Term
| Membranes maintain _____ of the cell. |
|
Definition
|
|
Term
| Membranes control the ____ of molecules into and out of the cell. |
|
Definition
|
|
Term
| Membranes regulate cell-cell ______. |
|
Definition
|
|
Term
| Uniform distribution of membrane proteins can be accomplished via ______. |
|
Definition
| insertion at localized sites. |
|
|
Term
| Membranes can ____ after injury |
|
Definition
|
|
Term
| ____ aggregation at localized sites of the PM is possible. |
|
Definition
|
|
Term
| _____ diffusion is restricted to own side of leaflet i.e. no spontaneous ______. |
|
Definition
Phospholipid
flip-flopping. |
|
|
Term
| Because phospholipid diffusion is restricted to own side of leaflet-no spontaneous flip-flopping. This maintains ______ |
|
Definition
|
|
Term
| membrane lipids are ______, meaning that they contain _____ & _____ regions. |
|
Definition
amphipathic
both polar and nonpolar |
|
|
Term
| Phospholipids Contain hydrophobic (nonpolar) _______ and polar (hydrophilic) ______. |
|
Definition
long chain fatty acids
head groups |
|
|
Term
| phosphatidylinositol (PI) are concentrated on the ____ leaflet. |
|
Definition
| Inner leaflet, except for GPI- anchored proteins |
|
|
Term
| _____ & _____ are important phospholipids in signal transduction pathways. |
|
Definition
| phosphatidylserine and phosphatidylinositol |
|
|
Term
| phosphatidylethanolamine (PE) are concentrated on the ____ leaflet. |
|
Definition
|
|
Term
| phosphatidylserine (PS) are concentrated on the ____ leaflet. |
|
Definition
| (Inner leaflet, neg. charged). |
|
|
Term
| sphingomyelin (PC) are concentrated on the ____ leaflet. |
|
Definition
|
|
Term
| sphingomyelin are concentrated on the ____ leaflet. |
|
Definition
|
|
Term
| _____ and _____ phospholipids are concentrated on the outer leaflet. |
|
Definition
| sphingomyelin & sphingomyelin (PC) |
|
|
Term
| Cholesterol contains a rigid ______ that increases membrane ______. |
|
Definition
steroid ring structure
packing |
|
|
Term
| The polar head group of cholestrol is ____ charged |
|
Definition
|
|
Term
|
Definition
|
|
Term
| Glycolipids derived from ____ instead of one of the major phospholipids named before. |
|
Definition
aka = glycosphingolipids
sphingosine |
|
|
Term
| The ______ of Glycolipids (=glycosphingolipids) is a carbohydrate |
|
Definition
|
|
Term
| Glycolipids (=glycosphingolipids) are found where? |
|
Definition
| exclusively in the outer leaflet |
|
|
Term
| Galactocerebroside are the main lipid component of the ________. |
|
Definition
| myelin sheath of nervous tissue |
|
|
Term
| Galactocerebroside is a type of _____ |
|
Definition
| Glycolipids (=glycosphingolipids) |
|
|
Term
| Gangliosides is a type of _____ |
|
Definition
| Glycolipids (=glycosphingolipids) |
|
|
Term
| Gangliosides found in the ____ of many cell types |
|
Definition
|
|
Term
| Gangliosides May involve localization of ____ at the cell surface |
|
Definition
|
|
Term
| Gangliosides are part of _____ in many cell types |
|
Definition
|
|
Term
| The lipid bilayer is a stable conformation for _____lipids in an aqueous environment |
|
Definition
|
|
Term
| Can lipid bilayers form spontaneously? |
|
Definition
|
|
Term
| The two leaflets of the lipid bilayer have _____ lipid compositions |
|
Definition
|
|
Term
| The outer (extracellular side) leaflet contains a higher concentration of: ________ |
|
Definition
| phosphatidylcholine, sphingomyelin, and glycolipids. |
|
|
Term
| Glycolipids are found only in the _____ leaflet. |
|
Definition
|
|
Term
| The inner leaflet is enriched in: ________ |
|
Definition
| phosphatidylserine and phosphatidylethanolamine. |
|
|
Term
| Cholesterol distribution with respect to the leaflets? |
|
Definition
|
|
Term
| The bilayer is ______ permeable to water |
|
Definition
|
|
Term
| The bilayer is weakly permeable to water, which can be enhanced considerably by the pore-forming, transmembrane proteins, _____ |
|
Definition
|
|
Term
| The bilayer is ____ permeable to small molecules such as oxygen and carbon dioxide |
|
Definition
|
|
Term
| The bilayer is ____ permeable to lipid-soluble hormones (eg. steroids) |
|
Definition
|
|
Term
| The water channels of the PM are very important for regulation of water retention in the _____. |
|
Definition
|
|
Term
| The bilayer is ______ permeable to macromolecules |
|
Definition
|
|
Term
| The bilayer is ______ permeable to ions. |
|
Definition
|
|
Term
| In the electron microscope the membrane appears ______. |
|
Definition
|
|
Term
| The trilaminar appearance of the PM under EM is due to the interaction of the electron-dense stain osmium tetroxide with the ______ of the membrane lipids but not with ________. |
|
Definition
polar headgroups
the central hydrophobic portion of the bilayer. |
|
|
Term
| The lipid bilayer serves as a "_____" for membrane proteins. |
|
Definition
|
|
Term
| Specialized areas of the PM serve ______. |
|
Definition
|
|
Term
| Lipid rafts are specialized “_____” within the plasma membrane. |
|
Definition
|
|
Term
| Lipid raft are enriched in: ______ |
|
Definition
| saturated phospholipids, cholesterol, glycolipids and a few proteins (including caveolin and GPI-anchored proteins). |
|
|
Term
| Lipid rafts are involved _____ signalling |
|
Definition
|
|
Term
| Lipid rafts are involved in _____ in the intestine |
|
Definition
|
|
Term
| Lipid rafts are a poorly defined route of ______ (not involving the protein clathrin) common to many cell types. |
|
Definition
|
|
Term
| Lipid rafts are ~_____nm in diameter |
|
Definition
|
|
Term
| Fusion of lipid rafts makes the PM ____, because of ______ |
|
Definition
thicker
due to the straighter fatty acid chains in the saturated lipids and the presence of sphingolipids |
|
|
Term
| Proteins within these domains of Lipid Rafts may be restricted from _____. |
|
Definition
|
|
Term
| Aberrant _____ metabolism in the brain, and therefore aberrant lipid raft functioning, facilitates the generation of ______ in Alzheimer’s patients. |
|
Definition
cholesterol
amyloid-beta peptide |
|
|
Term
| Lipid rafts may provide the necessary environment to convert ______ to the infectious form, thus facilitating the progression of various ____ diseases, including________. |
|
Definition
normal prion protein
prion
Creutzfeldt-Jacob disease (CJD) |
|
|
Term
| Various viruses (including those for HIV and influenza A) gain entry into cells via, __________ |
|
Definition
| raft-associated receptors (CD4, etc.) |
|
|
Term
| Various viruses (including those for HIV and influenza A) gain entry into cells via raft-associated receptors (CD4, etc.), while also making use of rafts to____ |
|
Definition
|
|
Term
| Caveolae, considered a subset of _____, is enriched in the protein _____. |
|
Definition
|
|
Term
| Caveolae are involved in a poorly described form of _____ as well as ______. |
|
Definition
|
|
Term
| Proteins perform most ____ membrane functions. |
|
Definition
|
|
Term
| Integral membrane proteins: ________ |
|
Definition
require disruption of the lipid bilayer to
be released from the membrane. |
|
|
Term
| Transmembrane proteins: span the membrane and have ____ and ____ domains. |
|
Definition
| intracellular and extracellular domains |
|
|
Term
| Domains within the lipid bilayer are more ______. |
|
Definition
|
|
Term
| Most receptors are ______ proteins. |
|
Definition
|
|
Term
| All transmembrane proteins are _____ membrane proteins. |
|
Definition
| integral (But not vice versa, necessarily!) |
|
|
Term
| Proteins that are covalently modified with fatty acid chains which insert into the lipid bilayer are ______ proteins, but not _____ proteins. |
|
Definition
integral membrane
transmembrane |
|
|
Term
| GPI-anchored proteins are attached to a _________ core in the lumen of the ER. |
|
Definition
| glycosylphosphatidylinositol (GPI) |
|
|
Term
| GPI-anchored proteins. These proteins are attached to a glycosylphosphatidylinositol (GPI) core in the lumen of the ER. Thus, after transfer to the plasma membrane these proteins are always oriented in the ____ monolayer. |
|
Definition
|
|
Term
| GPI-anchored proteins become part of _____. |
|
Definition
|
|
Term
| Peripheral membrane proteins: can be removed from the membrane by ______ |
|
Definition
| gentle extraction (including changes in the salt concentration or the pH) |
|
|
Term
| Peripheral membrane proteins are generally associated with the membrane by _____ |
|
Definition
| non-covalent interactions with other membrane proteins. |
|
|
Term
| Many cellular processes, such as proliferation (cell division) and gene expression, are regulated by ______. |
|
Definition
|
|
Term
| Receptors for chemical messages (ie, non-steroid hormones, neurotransmitters, and paracrine factors) are ______ proteins. |
|
Definition
|
|
Term
| The extracellular part of transmembrane receptors for chemical messages binds to the _____ and the intracellular portion initiates the intracellular response by ______ |
|
Definition
ligand (e.g., hormones)
interacting with other proteins inside the cell. |
|
|
Term
| As a general rule, each type of receptor is _____ for a particular hormone. |
|
Definition
|
|
Term
| Three major types of receptors are: |
|
Definition
1. Enzyme-linked
2. Ion channel-linked
3. G-protein-linked. (~1/2 of all known drugs work through G-protein coupled receptors.) |
|
|
Term
| Enzyme-linked receptors are often ____ enzymes. |
|
Definition
|
|
Term
| Steroid hormones are ________ and thus can _______. |
|
Definition
| lipid soluble and thus can diffuse through the plasma membrane |
|
|
Term
| Receptors for steroid hormones are ____ membrane proteins, but rather are soluble _______ proteins. |
|
Definition
not intergral
soluble cytosolic proteins |
|
|
Term
| The mechanism by which an extracellular chemical messenger is interpreted into an intracellular response is called ______. |
|
Definition
|
|
Term
| The result of signal transduction is that the initial signal (which may have been weak) gets ________. |
|
Definition
| gets amplified many times, at successive steps of the signal transduction pathway. |
|
|
Term
| Glycocalyx (or cell coat) is a carbohydrate-rich region on the external side of the plasma membrane formed primarily from the carbohydrate moieties of membrane ____ & _____ and from secreted (and transmembrane) _____ that adsorb to the cell surface. |
|
Definition
glycolipids and glycoproteins
proteoglycans |
|
|
Term
| The functions of the glycocalyx are still rather poorly defined, but may include: ______ |
|
Definition
| food molecules in the intestine destined for breakdown, recognition of other cells (T-cells, etc.), and protection of the cells from harsh environments (again, cells of the digestive tract). |
|
|
Term
| cytoskeleton-3 major filament systems: ______ |
|
Definition
| microfilaments, microtubules, and intermediate filaments. |
|
|
Term
| ________ are dynamic filament networks |
|
Definition
| Microfilaments and microtubules |
|
|
Term
| __________ are “polar” structures |
|
Definition
| Microfilaments and microtubules |
|
|
Term
| Microfilaments and microtubules have an _____ pool and a ______ pool of protein subunits. |
|
Definition
unpolymerized
polymerized |
|
|
Term
| what happens between the pools unpolymerized and polymerized subunits. |
|
Definition
| exchange protein subunits between the pools |
|
|
Term
| Various anti-cytoskeletal drugs can alter the _____ between the two pools. |
|
Definition
| steady-state (exchange of subunits between poly and unpoly pools) |
|
|
Term
| Microfilaments and microtubules have _____-growing (“plus”) and ____-growing (“minus”) ends |
|
Definition
|
|
Term
| Microfilaments and microtubules Have specific motor complexes that recognize the ______. |
|
Definition
|
|
Term
| Microfilaments and microtubules Are organized in the cytoplasm to appropriately exploit their _____ |
|
Definition
|
|
Term
| For MF, ______ polymerize to form ____-stranded filaments. |
|
Definition
|
|
Term
| MF Actin monomers polymerize to form double-stranded filaments. These strands wind around each other in a _____ conformation |
|
Definition
|
|
Term
| The double helical conformation formed by the winding of the double strand filaments for MF has a diameter of ____ |
|
Definition
|
|
Term
| Unlike MT, MF are not ______. |
|
Definition
|
|
Term
| ____ is one of the most ubiquitous and well-conserved proteins in nature. |
|
Definition
|
|
Term
| For MF there are ____ binding proteins |
|
Definition
|
|
Term
| actin binding proteins may either promote ____ or _____ of MFs |
|
Definition
polymerization
depolymerization |
|
|
Term
| Actin binding proteins may act to _____ into complex networks |
|
Definition
| link different MFs together |
|
|
Term
| Actin binding proteins may allow the _____ of MFs with other proteins and cytoskeletal systems. |
|
Definition
|
|
Term
| Myosin represents an MF-based ____ molecule |
|
Definition
|
|
Term
| Myosin represents an MF-based motor molecule, and is responsible for _______ |
|
Definition
| generating the force during muscle contraction |
|
|
Term
| MF length change occurs only by ______ |
|
Definition
| the addition or subtraction of subunits at the ends. |
|
|
Term
| For MF The ____ end grows faster than the ___ end. |
|
Definition
|
|
Term
| ATP-bound actin subunits bind on _____ end. |
|
Definition
|
|
Term
| ADP-bound actin subunits are ____ from the minus end |
|
Definition
|
|
Term
| Mechanism of assembly involves two steps: _____ |
|
Definition
|
|
Term
| In Nucleation for MF, ___ subunits are required to interact in the proper orientation to bind together and form a _____. |
|
Definition
|
|
Term
| In elongation for MF, subunits add on (head-to-tail) to the ______ at a ____ pace. |
|
Definition
|
|
Term
| What is the RDS of MF assembly? |
|
Definition
|
|
Term
| Drugs that affect turnover during assembly of MF therefore affect the _____ of MF. |
|
Definition
|
|
Term
|
Definition
|
|
Term
| Phalloidin is a ______ toxin |
|
Definition
|
|
Term
|
Definition
|
|
Term
| Fluorescently labeled phalloidin is often used to stain ____ instead of _____ antibodies. |
|
Definition
|
|
Term
|
Definition
|
|
Term
| MF severing protein: ______ |
|
Definition
|
|
Term
| MF Bundling (cabling) protein in stress fibers: _____ |
|
Definition
|
|
Term
| MF Bundling (cabling) protein in filopodia: _____ |
|
Definition
|
|
Term
| MF Meshwork X-linkers (Cross-linking protein): ______ |
|
Definition
|
|
Term
| MF Membrane attachment proteins: _____ |
|
Definition
spectrin
ERM family proteins like ezrin and moesin |
|
|
Term
| ERM protein family {WIKI} |
|
Definition
he ERM protein family consists of three closely related proteins, ezrin, radixin and moesin.
ERM proteins crosslink actin filaments with plasma membranes. |
|
|
Term
| The Nucleating/sequestering proteins of MF help ______ |
|
Definition
|
|
Term
| MF Nucleating proteins: _____ |
|
Definition
|
|
Term
| Arp 2/3 is a complex of proteins that _____ new filaments from the sides of ______ |
|
Definition
nucleates
pre-existing filaments |
|
|
Term
| Formins nucleate new filaments _____ |
|
Definition
|
|
Term
| Profilin _____ actin subunits and keeps them from ______. |
|
Definition
sequesters
assembling onto new filaments |
|
|
Term
| Arp 2/3 is an example of a MF ____ protein. |
|
Definition
|
|
Term
| Profilin is an example of a MF _____ protein. |
|
Definition
|
|
Term
| Formins are an example of a MF ____ protein. |
|
Definition
|
|
Term
| The Cell Cortex of MF is a cytoplasmic region near the _____ contains a rich network of actin MF and some actin binding proteins, especially ______. |
|
Definition
cytoplasmic region near the plasma membrane contains a rich network of actin MFs
spectrin |
|
|
Term
| spectrin is a ____ protein for MF. |
|
Definition
| Membrane attachment protein |
|
|
Term
| Membrane attachment proteins the _____. |
|
Definition
|
|
Term
| Can secretory vesicles must traverse the Cell Cortex of MF? |
|
Definition
|
|
Term
| ______ are a major component of the contractile apparatus in muscle. |
|
Definition
|
|
Term
| In muscle, the actin filaments can be observed in highly ordered arrays with ______. |
|
Definition
| the motor protein myosin II |
|
|
Term
| Muscle sarcomeres/myofibrils are examples of _____ structures. |
|
Definition
|
|
Term
| Stress fibers are bundles of: ______ |
|
Definition
| MF, Myosin II, and alpha actin |
|
|
Term
| Stress fibers are an example of a MF _____ |
|
Definition
|
|
Term
| Stress fibers are found near the_____ of _____ cells |
|
Definition
plasma membrane
non-muscle |
|
|
Term
| Stress fibers are found near the plasma membrane of non-muscle cells, especially ____ cells of large _____. |
|
Definition
|
|
Term
| Microvilli, a ____ structure. |
|
Definition
|
|
Term
| Microvilli are a specialized are of _____ |
|
Definition
|
|
Term
| Microvilli are a specialized are of MF cortex found in ________ cells contains numerous microvilli |
|
Definition
|
|
Term
| The microvilli of intestinal epithelial cells contain a contain a core bundle of MFs plus _____ and other actin binding proteins like ____ & ____. |
|
Definition
|
|
Term
| Contractile ring, a ___ structure. |
|
Definition
|
|
Term
| Contractile ring, a MF structure, is a circumferential ring of MFs, along with _____ cross-bridges and _____ anchors |
|
Definition
|
|
Term
| Contractile ring, a MF structure, is found adjacent to the ______ of _____ cells |
|
Definition
cytoplasmic surface of the plasma membrane
dividing |
|
|
Term
|
Definition
| is the process in which the cytoplasm of a single eukaryotic cell is divided to form two daughter cells. |
|
|
Term
| Cells undergoing Cytokinesis would have a _____ present near their PM. |
|
Definition
|
|
Term
| Focal contact is not really actin-containing structure, but an accessory structure that _______. |
|
Definition
| “hooks up” to microfilaments |
|
|
Term
| Invadosomes, a _____ structure. |
|
Definition
|
|
Term
| Invadosomes, a MF structure, are a small area located _____, often near the _____ |
|
Definition
under the PM
Golgi Apparatus |
|
|
Term
| Invadosomes a MF structure, that is a small area located under the PM, often near the Golgi Apparatus, is composed of actin filaments, ______ proteins, and on the _____ side _______. |
|
Definition
| actin filaments, focal contact proteins, and (on the extracellular side) metalloproteinases. |
|
|
Term
| Invadosomes function may be to extend processes that _______ to facilitate _____ |
|
Definition
degrade the local ECM (Extracellular matrix)
motility |
|
|
Term
| Invadosomes may also facilitate invasion of ______. |
|
Definition
|
|
Term
| Two examples of Invadosomes: _____ |
|
Definition
|
|
Term
| Which is the more abundant of the Invadosomes, Podosomes or Invadopodia? |
|
Definition
|
|
Term
| Which is extends more deeply into the ECM of the Invadosomes, Podosomes or Invadopodia? |
|
Definition
Invadopodia (extends Deeper)
Podosomes (shallow) |
|
|
Term
| Which lives longer of the Invadosomes, Podosomes or Invadopodia? |
|
Definition
|
|
Term
| Which is associated with a "more invasive function" the Invadosomes, Podosomes or Invadopodia? |
|
Definition
|
|
Term
|
Definition
Muscle contraction
Cell motility
Cytokinesis |
|
|
Term
| Cell motility is Characteristic of: ____ and many cell types during ______. |
|
Definition
| immune (macrophages, eosinophils, neutrophils) fibroblasts, endothelial cells, and many cell types during development. |
|
|
Term
| Cell motility usually requires the receipt of an ______. |
|
Definition
|
|
Term
| Cell motility usually requires the receipt of an extracellular signal, either ____ or ______ |
|
Definition
|
|
Term
| Mechanical extracellular signal example _____ |
|
Definition
| loss of contact with neighboring cells |
|
|
Term
| Cell motility is driven by _____ rearrangements and ____ production |
|
Definition
|
|
Term
| Cell motility may always require the presence of ______. |
|
Definition
|
|
Term
| For Cell motility in addition to the presence of invadosomes it also requires the activities of: ______ |
|
Definition
| filopodia, lamellopodia, contractile stress fibers, differential adhesion to the substratum, and (for directional motility) a rearranged microtubule cytoskeleton. |
|
|
Term
| The actin binding protein dystrophin binds to both actin and the plasma membrane of _____ & _____ cells. |
|
Definition
|
|
Term
| The actin binding protein dystrophin binds to both actin and the plasma membrane of muscle and neuronal cells. When defective, it gives rise to the _____ disorders |
|
Definition
| Duchenne/Becker muscular dystrophy |
|
|
Term
| Dystrophin normally impart strength and flexibility to muscle cell plasma membranes during cycles of _____ & ______. |
|
Definition
| contraction and relaxation. |
|
|
Term
| The neurofibromatosis type II gene encodes a protein, _______. |
|
Definition
|
|
Term
| The neurofibromatosis type II gene encodes a protein (merlin) that acts as an actin-binding protein. Merlin may bind both to actin filaments and the plasma membrane in _______ cells. |
|
Definition
|
|
Term
| merlin is part of the _____ family of actin binding proteins. |
|
Definition
|
|
Term
| Certain pollen allergies are caused by an immune response to plant ____. |
|
Definition
|
|
Term
|
Definition
| Sequestering actin subunits |
|
|
Term
| Two forms of a cardiac muscle actin-binding protein, _______ & ______ are found in the blood after a mild heart attack. |
|
Definition
| troponin I and troponin T |
|
|
Term
| Cancer cells often possess an enhanced ability to move _______ and past _____ to enter (and later exit) the bloodstream, to set up new sites of growth (metastasis). |
|
Definition
|
|
Term
| The process of metastasis by cancer cells involves ______ and sometimes altered forms of _______. |
|
Definition
| cytoskeleton-interacting proteins (e.g., src signalling protein). |
|
|
Term
| _______ compose about 15% of soluble protein in brain tissue |
|
Definition
|
|
Term
|
Definition
|
|
Term
| MT are found in all _____ cells. |
|
Definition
|
|
Term
| The main family members of MT are: _____ |
|
Definition
| α, β, and γ-tubulin (share ~35-40% identity) |
|
|
Term
| MT are part of the _____ superfamily |
|
Definition
|
|
Term
| MT are part of the G-protein superfamily, they have _____ activity and tubulin _____ have been strongly implicated in some signal transduction pathways. |
|
Definition
|
|
Term
| MTs are ____nm diameter fibers of varying lengths; hollow with a ___nm lumen. |
|
Definition
|
|
Term
| MT consist of ____ longitudinally oriented _____. |
|
Definition
|
|
Term
| A protofilament is composed of _____ |
|
Definition
| dimers of α and β tubulin |
|
|
Term
| Most MTs are initially formed at a perinuclear structure known as the _____, and remain _____ after they have polymerized. |
|
Definition
|
|
Term
| The centrosome consists of ______ and _____ material |
|
Definition
two centrioles (MT structures)
pericentriolar material (PCM-protein aggregates that associate specifically with centrioles) |
|
|
Term
| Centrioles are used as templates for the growth of _______, but are not involved in directly nucleating the growth of ______. |
|
Definition
cilia and flagella.
cytoplasmic MTS |
|
|
Term
| Centrioles possess _____ of MT, held together by _____ |
|
Definition
nine triplets
protein linkers |
|
|
Term
| ____ MTs in triplet of centriole are incomplete MTs |
|
Definition
|
|
Term
| The centrioles within the pair are arranged _______. |
|
Definition
| orthogonally (perpendicularly |
|
|
Term
|
Definition
|
|
Term
| PCM contains _______, which is directly responsible for _______. |
|
Definition
γ-tubulin
MT nucleation and elongation. |
|
|
Term
| The γ-tubulin contained in the PCM acts as ______. |
|
Definition
| “seeds” for cytoplasmic MT growth. |
|
|
Term
| 2 centrioles plus PCM = _____ |
|
Definition
|
|
Term
| Do MT undergo random polymerization in the cytoplasm? |
|
Definition
| No, The presence of “seeds” at the centrosome makes it the preferred site for MT growth |
|
|
Term
| Tublin dimers are hetero or homo? |
|
Definition
| heterodimers (alpha/beta) |
|
|
Term
| Tubulin heterodimers assemble into ____. |
|
Definition
|
|
Term
| Only tubulin subunits which have a ________ molecule bound to them will polymerize. |
|
Definition
|
|
Term
| Once in an MT, each subunit soon _____ ; therefore, tubulin is a ____(enzyme). |
|
Definition
hydrolyzes one phosphate of its GTP to make a GDP
GTPase |
|
|
Term
| Under steady-state conditions, there will normally exist together a pool of _____ subunits and a pool of ______ subunits for MT within the cell. |
|
Definition
polymerized
unpolymerized |
|
|
Term
| The plus ends of MT are at ______, while the minus ends are _______. |
|
Definition
the cell periphery
embedded in the centrosome. |
|
|
Term
|
Definition
| Microtubule-associated proteins |
|
|
Term
| Structural MAPs, Brain MAPs: _______, Non-neuronal MAPs: _____. |
|
Definition
Brain MAPs: 1, 2, and tau*
non-neuronal MAP4 |
|
|
Term
| Structural MAPs (Brain MAPs 1, 2, and tau; non-neuronal MAP4) aid in _____ and do what? |
|
Definition
| MT assembly and cross-link MTs. |
|
|
Term
| MAPs that are motor molecules: ______ |
|
Definition
|
|
Term
| Kinesin moves cargo toward the ____ ends of MTs. |
|
Definition
|
|
Term
| Dynein moves cargo toward the ____ ends of MTs. |
|
Definition
|
|
Term
| Cytoplasmic MTs. Arise from the _____ with ____ ends distal. |
|
Definition
|
|
Term
| Cytoplasmic MTs are involved in the Intracellular transport of: _____ . |
|
Definition
| vesicles, mRNAs, signalling complexes. |
|
|
Term
| Cytoplasmic MTs are involved in the Spatial distribution of _____ |
|
Definition
| major organelles, including the endoplasmic reticulum, mitochondria, lysosomes, Golgi apparatus. |
|
|
Term
| Cytoplasmic MTs are involved in protein trafficking between ________ |
|
Definition
|
|
Term
| Cytoplasmic MTs control directional, ______ |
|
Definition
|
|
Term
| Cytoplasmic MTs change the cell's ____ |
|
Definition
|
|
Term
| MT are the ____ of cilia and flagella |
|
Definition
|
|
Term
| MT serve as a _____ apparatus, the structure upon which ________. |
|
Definition
Mitotic
chromosomes are separated to daughter cells. |
|
|
Term
| The MT Mitotic apparatus serves in the Separation of the chromosomes in ____ part of mitosis. |
|
Definition
|
|
Term
| The MT Mitotic apparatus is involved in the induction and placement of the _____ |
|
Definition
|
|
Term
| The MT Mitotic apparatus is involved in the formation of the _______. |
|
Definition
| mitotic apparatus, or spindle. |
|
|
Term
| In MT there exists _____ in the center within the center sheath and _____ on the outside. |
|
Definition
2 central singlet MTs
alpha and beta MT outer doublets |
|
|
Term
| Clearance of mucous by the respiratory epithelium is an example of propelent of materials by ______ |
|
Definition
| ciliated cells (resp epithelium) |
|
|
Term
| How are oocyte passed to the uterus along the epithelium of the oviduct? |
|
Definition
| ciliated cells (resp epithelium) |
|
|
Term
| The beating of the ____ of spermatozoa is responsible for their motility. |
|
Definition
|
|
Term
| Cells with flagella usually have how many? |
|
Definition
|
|
Term
| For both cilia and flagella, the ____ generates motion by the ______. |
|
Definition
axoneme (MT)
sliding of filaments against each other. |
|
|
Term
| The sliding motion used in axoneme (MT) of cilia and flagella to produce movement requires the action of ________ |
|
Definition
| axonemal dynein and ATP hydrolysis (to provide the required energy) |
|
|
Term
| The whip-like movement of cilia and flagella requires the interaction of MTs with ______. |
|
Definition
| radial spoke protein and an axoneme-specific form of dynein |
|
|
Term
| The whip-like movement of cilia and flagella requires the interaction of MTs with radial spoke protein and an axoneme-specific form of dynein, this complex is called the |
|
Definition
| ciliary or flagellar axoneme |
|
|
Term
| The growth of the axoneme occurs via the activity of a ______ with specialized function called the _____. |
|
Definition
subplasmalemmal centriole
basal body |
|
|
Term
| The MTs of the axoneme have a ____ arrangement. |
|
Definition
| "9 + 2" arrangement with nine “doublet” MTs arranged in a ring around a central (singlet) pair of MTs. |
|
|
Term
| It is still a mystery how a “9 (doublet) + 2” arrangement in the axoneme arises from the _______ arrangement of the basal body. |
|
Definition
|
|
Term
| Primary cilia, which are present in most cell types as _____ structures. |
|
Definition
|
|
Term
| One BIG difference between primary cilia and "regular" cilia is that _______ or that the PM of primary cilia are often ______. |
|
Definition
the axonemal arrangement of MTs may vary
enriched with receptors specific for certain signal transduction pathways. |
|
|
Term
| The primary function of primary cilia is to act as a _____. |
|
Definition
|
|
Term
| _____ cells represent an important example of primary cilium function. |
|
Definition
|
|
Term
| Other cell types in addition to the Olfactory cells which primary cilia function is important include the: ________. |
|
Definition
| Hair cells of the inner ear and the light-sensing cells of the retina. |
|
|
Term
| Primary ciliary dyskinesia (PCD) occurs in _____ births. |
|
Definition
|
|
Term
| Primary ciliary dyskinesia (PCD, “Kartagener’s Syndrome”) is a _____ defect |
|
Definition
| genetic (autosomal recessive) |
|
|
Term
| Primary ciliary dyskinesia (PCD, “Kartagener’s Syndrome”) leads to ______, caused by defects in either the ______ or in the ______ (wherein it is called _____) |
|
Definition
immotility of the axoneme
inner or outer dynein arms (90%)
radial spokes
"Young's syndrome" |
|
|
Term
| Patients with Primary ciliary dyskinesia (PCD, “Kartagener’s Syndrome”) are susceptible to _______. |
|
Definition
| frequent respiratory tract infections (rhinitis, sinusitis, otitis media, and bronchiectasis) |
|
|
Term
| Males with Primary ciliary dyskinesia (PCD, “Kartagener’s Syndrome”) have _____, while females can suffer from ______ & _____ pregnancies. |
|
Definition
| Males often have immotile sperm, while females can suffer from infertility and ectopic pregnancies |
|
|
Term
|
Definition
|
|
Term
| In Primary ciliary dyskinesia (PCD, “Kartagener’s Syndrome”) hydrocephalus internus may result from inactivity of the cells that ___________. |
|
Definition
| line the ventricles of the CNS |
|
|
Term
| Aberrant mitoses in neoplasia is one indicator of ______. |
|
Definition
| the development of cancer |
|
|
Term
| one indicator of the development of cancer is the presence of cells undergoing abnormal division, often involving the formation of more than two _____ resulting from the production of too many ______. |
|
Definition
spindle poles
centrosomes |
|
|
Term
| The antimitotic drugs _____ & _____ kill dividing cells by depolymerizing the ______. |
|
Definition
vincristine (Oncovin) and vinblastine
mitotic spindle MTs. |
|
|
Term
| Paclitaxel, a Cancer chemotherapy, halts cell division by _________ |
|
Definition
| stabilizing the mitotic spindle and not allowing any MTs to depolymerize. |
|
|
Term
| Paclitaxel has been used most often to treat patients having ______ cancers. |
|
Definition
| either ovarian or breast cancers. |
|
|
Term
| colchicine has been used to treat patients with _____. |
|
Definition
|
|
Term
| colchicine has been used to treat patients with gout, It's action involves the suppression of the activation of _____. |
|
Definition
|
|
Term
| Colchicine is also used in the technique of chromosome isolation for ______. |
|
Definition
|
|
Term
| In Alzheimer's disease the MAP called, _____, is abnormally ______ and truncated in this disease |
|
Definition
|
|
Term
| In Alzheimer's disease the MAP called, tau, comprises the ______ found in Alzheimer's plaques, within the so called ______ |
|
Definition
paired helical filaments
"neurofibrillary tangles" |
|
|
Term
| Diseases involving faulty functioning of primary (non-motile) cilia: |
|
Definition
i. Polycystic kidney disease (PKD).
ii. Retinal degeneration
iii. Bardet-Biedl syndrome |
|
|
Term
| In Polycystic kidney disease (PKD), cells lining the urinary tubes cannot ______, and as a result _____ too much as a response, and form _____ in the kidney. |
|
Definition
sense the flow of urine
proliferate
large cysts |
|
|
Term
| Polycystic kidney disease (PKD) involves gene defects for the ________. |
|
Definition
| Ca-channel proteins polycystins 1 and 2 |
|
|
Term
| Retinal degeneration can result from faulty functioning of primary (non-motile) cilia, because ________. |
|
Definition
| the inner and outer segments of both rods and cones are connected by a primary cilium that is required for proper transport of material. |
|
|
Term
| Bardet-Biedl syndrome is characterized by _____ & _______, due to defects in _____. |
|
Definition
retinal degeneration & early-onset obesity
in cilium/basal body construction |
|
|
Term
| Bardet-Biedl syndrome is an example of a condition resulting from faulty _____ |
|
Definition
| primary (non-motile) cilia |
|
|
Term
| Cytoplasmic IFs are ________ in eukaryotes. |
|
Definition
| not universally expressed in eukaryotes |
|
|
Term
| There are more than ____ types of IF proteins. |
|
Definition
|
|
Term
| Microvili are composed of ______ |
|
Definition
|
|
Term
|
Definition
|
|
Term
| IF have a long, ______ region in the center, and two _____ ends. |
|
Definition
α-helical coiled coil
globular |
|
|
Term
| The coiled-coils of IF contain ____ repeats to allow ______. |
|
Definition
|
|
Term
| Changes in salt concentrations, pH, cold temps, or addition of chaotropes does or does not disassemble IFs |
|
Definition
|
|
Term
|
Definition
|
|
Term
| ____ different classes of IFs which are expressed in _____ ways. |
|
Definition
|
|
Term
| Type I IF: Acidic keratins are found where? |
|
Definition
|
|
Term
| Type II IF: Basic keratins are found where? |
|
Definition
|
|
Term
| Type III IF: Desmin are found where? |
|
Definition
|
|
Term
| Type III IF: Vimentin are found where? |
|
Definition
| Mesenchymal cells (fibroblasts) |
|
|
Term
| Type III IF: GFAP are found where? |
|
Definition
| Astrocytes, Schwann cells |
|
|
Term
| Type III IF: Peripherin are found where? |
|
Definition
|
|
Term
| Type IV IF: Neurofilaments are found where? |
|
Definition
|
|
Term
| Type V IF: Lamins are found where? |
|
Definition
|
|
Term
|
Definition
|
|
Term
| IF-associated proteins: ________ |
|
Definition
Plectin.
Desmoplakin.
BP230.
Filaggrin. |
|
|
Term
|
Definition
| links IFs to MTs and MFs. It is an IFAP |
|
|
Term
|
Definition
| links IFs to cell-cell junctions. It is an IFAP |
|
|
Term
|
Definition
| Links IFs to hemidesmosomes in epithelial cells. It is an IFAP |
|
|
Term
|
Definition
| Bundles keratin filaments in skin epithelia. It is an IFAP |
|
|
Term
| In IF assembly Monomers bind to form ________. |
|
Definition
| parallel, coiled-coil dimers |
|
|
Term
| In IF assembly Monomers bind to form parallel, coiled-coil dimers. The dimers then bind to each other in an _____ fashion to form ______. |
|
Definition
anti-parallel
staggered tetramers. |
|
|
Term
| The tetramers formed in IF are equivalent to actin monomers in solution, but are NOT structurally _____ , because of _____ arrangement. |
|
Definition
|
|
Term
| In IF assembly Monomers bind to form parallel, coiled-coil dimers. The dimers then bind to each other in an anti-parallel fashion to form staggered tetramers. The tetramers then form _______ which comprise the IF. |
|
Definition
| 8 parallel protofilaments |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
| Intermediate Filament Functions include maintaining the position of ______. |
|
Definition
| the position of the nucleus |
|
|
Term
| Intermediate Filament Functions include maintaining the size of _____ |
|
Definition
| size (caliber) of large axons |
|
|
Term
| Intermediate Filament providing the major constituent of _____ and the _____ of skin. |
|
Definition
hair
outerlayer (Protective function.) |
|
|
Term
| Intermediate Filament Functions in the _____ integrity of cells/tissues |
|
Definition
|
|
Term
| How do pathologists often determine origin of tumor? |
|
Definition
| stain for IF proteins to determine the cell type of origin for that tumor. Since there are different types of IF proteins that are specific for certain cell types. |
|
|
Term
| Hereditary skin blistering disease (_______), is caused bymutant ____ proteins that possess faulty ____ abilities, resulting in hemidesmosomes that lack structural integrity and skin tissue that blisters and does not hold together well. |
|
Definition
epidermolysis bullosis
cytokeratin
assembly |
|
|
Term
| Transgenic mice possessing mutagenized neurofilament proteins display symptoms of ______ |
|
Definition
| amyotrophic lateral sclerosis (Lou Gehrig's disease). |
|
|
Term
Mutant cytokeratin (IF) proteins results in epidermolysis bullosa, a
serious blistering condition, where cells in the ______ become disrupted. |
|
Definition
|
|
Term
| One hallmark of liver cirrhosis is the presence of _____, cytosolic aggregates of _______. |
|
Definition
Mallory bodies
intermediate filament proteins. |
|
|
Term
| Defects in the gene for ____ underlie the CNS disease called Alexander disease. |
|
Definition
|
|
Term
| Defects in the gene for GFAP underlie the CNS disease called Alexander disease, wherein the affected individual may develop ________ with macrocephaly, seizures, and psychomotor retardation. |
|
Definition
| leukoencephalopathy (brain infections) |
|
|
Term
| ______ are “polar” structures |
|
Definition
|
|
Term
| Microfilament assembly requires two steps: ______ |
|
Definition
| nucleation and elongation. |
|
|
Term
| Microfilament networks can be modified by turning over the actin subunits within individual filaments. The mechanism by which this is accomplished is called “______”. |
|
Definition
|
|
Term
The “cortex” of the cell, which is found _____, is usually enriched in
______. |
|
Definition
underlying the PM
microfilaments |
|
|
Term
| Some cells display thick cables of microfilaments called “_____”, |
|
Definition
|
|
Term
| ______are a major component of the contractile ring. |
|
Definition
|
|
Term
| _____ are like cellular “rivets”, that connect the ______ with external fibers or molecules. |
|
Definition
Focal contacts
internal cytoskeleton |
|
|
Term
| Dystrophin is an ____-binding protein |
|
Definition
|
|
Term
| Plant _____ acts as an allergen in some people. |
|
Definition
|
|
Term
| _______ are used as markers for heart attacks |
|
Definition
| Troponin I and troponin T (MF) |
|
|
Term
| The centrosome (THE PCM NOT THE CENTRIOLE) _____ and organizes the microtubule array in most cells. |
|
Definition
|
|
Term
| Centrioles and _____ have similar structures. |
|
Definition
| basal body (9 sets of triplets) |
|
|
Term
| Microtubules assemble from dimers with their ‘__’ ends buried in the centrosome and their ‘__’ ends arrayed in the cytoplasm. |
|
Definition
|
|
Term
| MAPs bind to the walls of ___ and do what? |
|
Definition
|
|
Term
|
Definition
| kinesin + end and dynein - end |
|
|
Term
| ___ “fill” the cytoplasm, allowing them to move cargo throughout the cell and maintain normal organelle distribution in the cell. |
|
Definition
|
|
Term
| The mitotic apparatus is composed mainly of ____ |
|
Definition
|
|
Term
| Tight regulation of ____ is required for mitosis to be completed successfully. |
|
Definition
|
|
Term
| Anti-MT drugs are used in chemotherapy because they “trap” cells in ____ and do not allow them to ____. |
|
Definition
|
|
Term
| parts of the axoneme: ______ |
|
Definition
doublet MTs, radial spokes, central
pair MTs, and dynein (outer and inner) arms. |
|
|
Term
| The _____ of MT convert the sliding motion of adjacent doublets into a bending motion |
|
Definition
|
|
Term
| Primary cilia are sensory structures, and are important during _______. |
|
Definition
|
|
Term
| _____-coated balloons are used in cardiac procedures to prevent restenosis (proliferation of smooth muscle cells). |
|
Definition
|
|
Term
|
Definition
| Anti-cancer chemotherapeutic drugs that acts by being anti MT |
|
|
Term
| ENDOPLASMIC RETICULUM has a Membrane system that extends from the _____ to the _____. |
|
Definition
outer nuclear membrane
plasma membrane |
|
|
Term
| A Liver Cell (Hepatocyte) has more or less rough or smooth ER than a Pancreatic Exocrine Cell? |
|
Definition
| Liver Cell (Hepatocyte) has more smooth ER but less rough ER |
|
|
Term
| The ER extends from the nucleus to the plasma membrane, and “fills” the ____ with an anastomosing network. |
|
Definition
|
|
Term
| The ER lumenal space occupies ~___% of the total cell volume and contains proteins at an estimated concentration of ___ mg/ml. |
|
Definition
|
|
Term
| The extended distribution of the ER is generated by interaction with _____, using the motor protein ____, to pull the membranes peripherally in the cell. |
|
Definition
|
|
Term
| It has been estimated that the “average” cell produces between ______ proteins per minute at the ER membrane. |
|
Definition
|
|
Term
| The lumenal compartment of the ER is topologically equivalent to the _____ |
|
Definition
|
|
Term
| The ER is the site of production of _____ proteins and ____for most of the other organelles. |
|
Definition
|
|
Term
| Most cellular lipids are manufactured in the ____. |
|
Definition
|
|
Term
| Cellular lipids are manufactured in the ER membranes who have their active site on the _____ side |
|
Definition
|
|
Term
| phospholipid synthesis occurs exclusively in the ____ leaflet of the ER membrane. |
|
Definition
|
|
Term
| Fatty acids are transported to the ER by _____. |
|
Definition
| fatty acid-binding proteins (FABPs). |
|
|
Term
| ______ in the ER membrane add two _____ to glycerol phosphate, forming phosphatidic acid. |
|
Definition
Acyl transferases
fatty acids |
|
|
Term
| Although phospholipid synthesis occurs in the cytosolic leaflet, the ER itself shows a _______. |
|
Definition
| fairly uniform distribution of all phospholipids between the two leaflets. |
|
|
Term
| The equilibration of the ER membrane with respect to is effected by the ER membrane protein called scramblase |
|
Definition
|
|
Term
| scramblase is a member of the “_______” family of proteins. |
|
Definition
|
|
Term
| In contrast to the ER, the plasma membrane exhibits ______. |
|
Definition
| an asymmetric distribution of phospholipids |
|
|
Term
| _______ are found exclusively in the cytosolic leaflet of the ER membrane. |
|
Definition
|
|
Term
| The uneven distribution found in the PM is facilitated by proteins called _______. |
|
Definition
|
|
Term
| The cell cycle is an orderly and _____ sequence of events whereby cells duplicate their cellular constituents before dividing in two. |
|
Definition
|
|
Term
| Some aspects of the cell cycle are universally _______. |
|
Definition
|
|
Term
| Cells must _____ DNA & ______ chromosomes equally before dividing into daughter cells |
|
Definition
| accurately replicate their DNA and then correctly segregate chromosomes equally |
|
|
Term
Additionally, cells must faithfully
duplicate their ______ & _____ and distribute them equally upon cell division. |
|
Definition
| organelles and most of their macromolecules |
|
|
Term
| Clinical correlates: Disruption of normal cell cycle control can lead to the unbridled _____ observation in cancer |
|
Definition
|
|
Term
| Disruption of normal cell cycle control can lead to loss of the ability to undergo normal _______ |
|
Definition
| programmed cell death known as apoptosis |
|
|
Term
| Disruption of normal cell cycle control can lead to premature ____ & _____ of cells |
|
Definition
|
|
Term
Disruption of normal cell cycle control can lead to loss of proliferative potential leading to an
inability of cells to _______. |
|
Definition
| regenerate and/or tissues to heal. |
|
|
Term
| Cell cycle progression and the time it takes to transit the cell cycle are _______ regulated. |
|
Definition
|
|
Term
| The average time it takes eukaryotic cells to divide has an ______. |
|
Definition
|
|
Term
| The eukaryotic cell cycle is divided into ____ phases |
|
Definition
|
|
Term
| ____ phase can be seen easily in light microscopy. |
|
Definition
|
|
Term
|
Definition
|
|
Term
| Mitosis is the process whereby the ____ |
|
Definition
|
|
Term
|
Definition
|
|
Term
| M-Phase further divided into ____ sub‐phases |
|
Definition
|
|
Term
| At the conclusion of M‐phase, cells _______ |
|
Definition
| divide into two by a process known as cytokinesis |
|
|
Term
| Mitosis is the _____ and most _____ phase of the cell cycle. |
|
Definition
|
|
Term
| ______ length is highly variable |
|
Definition
|
|
Term
| The time between two mitoses is called _____ |
|
Definition
|
|
Term
| Interphase is sub‐divided into: _____ |
|
Definition
|
|
Term
| G1‐ and G2‐ are abbreviations for ___ and are recognized as phases when cells _______. |
|
Definition
gap
prepare for either S‐phase or mitosis. |
|
|
Term
| G1‐phase is the ____ & ____ of the four phases. |
|
Definition
| longest and most variable |
|
|
Term
| During this G1, cells synthesize ____, translate proteins and ______. |
|
Definition
|
|
Term
| MPF is a _____ factor. (Location) |
|
Definition
|
|
Term
| The activity of MPF was high in ____ and low during _____. |
|
Definition
|
|
Term
| _____ can promote M‐phase in a naïve cell |
|
Definition
|
|
Term
| injection of MPF generated more ____ in a seemingly endless _______ feedback loop |
|
Definition
|
|
Term
| Biochemists working in clams identified a protein whose levels rose and fell during the cell cycle and peaked in M‐phase which they called _____. |
|
Definition
|
|
Term
| MPF is a _____ dependent ______. |
|
Definition
|
|
Term
| MPF is a cyclin dependent kinase whose activity rises and falls with ______ |
|
Definition
|
|
Term
| MPF is a cyclin dependent kinase whose activity rises and falls with B-Cyclins, which are actively destroyed via a _____ process at the end of _____. |
|
Definition
ubiquitination dependent
M‐phase |
|
|
Term
| The activation of MPF involves more than just the binding of cyclin to ____. |
|
Definition
|
|
Term
| Following the association of cyclin with Cdks, an _____ and ______, which _____ independent sites on the ____. |
|
Definition
inhibitory kinase
an activating kinase
phosphorylate
Cdk |
|
|
Term
| Following the association of cyclin with Cdks, an inhibitory kinase and an activating kinase phosphorylate independent sites on the Cdk. However, these Cdks are still inactive until ___________ |
|
Definition
| an activating phosphatase removes the inhibitory phosphate. |
|
|
Term
| Following the association of cyclin with Cdks, an inhibitory kinase and an activating kinase phosphorylate independent sites on the Cdk. However, these Cdks are still inactive until an activating phosphatase removes the inhibitory phosphate. This phosphatase is itself activated by ____ generating _______. |
|
Definition
active MPF
the positive feedback loop originally observed. |
|
|
Term
| In the simplest sense, the cell cycle is governed by ____ whose activity rises and falls ___ per cycle. |
|
Definition
|
|
Term
| humans have ____ Cdks: _____ that are constitutively expressed. |
|
Definition
3
(Cdk1, Cdk2, Cdk4, and Cdk6) |
|
|
Term
| Humans have ____ cyclins: _____ |
|
Definition
| four cyclins (cyclins D, E, A, and B) |
|
|
Term
| cyclins help activate _____ |
|
Definition
|
|
Term
| What cyclins are expressed during G1/S‐phase? |
|
Definition
|
|
Term
| What cyclins are expressed during S/G2‐phase? |
|
Definition
|
|
Term
| What cyclins are expressed during G2/M‐phase? |
|
Definition
|
|
Term
| starting in early G1‐phase, ____ & ____ are initially _____ by cyclins. |
|
Definition
|
|
Term
| Although Cdk4 and Cdk6 are initially unbound at the begining of G1-phase, as cells progress thru G1‐phase, these Cdks become increasingly bound and activated by ______. |
|
Definition
|
|
Term
| ______ complexes promote progression past the “Restriction point” and induce the expression of _____ which binds to and activates _____. |
|
Definition
cyclin D‐Cdk4/6
cyclin E
Cdk2 |
|
|
Term
| The expression of cyclin A is induced after ______. Cylcin A then binds _____ in early _‐phase and ____ late in _‐phase. |
|
Definition
Cyclin E binds and activated Cdk2
Cdk2 early in S-phase
Cdc2 (Cdk1) late s-Phase |
|
|
Term
|
Definition
|
|
Term
| Cdc2 (Cdk1) induces the expression of ______, which binds to Cdk1 and promotes ______. |
|
Definition
|
|
Term
| Following the initiation of mitosis, the remaining cyclins are actively destroyed by the _______ |
|
Definition
| Anaphase Promoting Complex (APC) |
|
|
Term
| The destruction of the remaining cyclins by Anaphase Promoting Complex (APC) does what? and allows the cell to do what? |
|
Definition
| resets the cell cycle and allows cells to exit M‐phase and enter G1‐phase |
|
|
Term
| In contrast to cyclins ______, cyclins _____ are constitutively unstable and repression of their mRNA expression is sufficient to protein levels to fall. |
|
Definition
Cylcins A and B stable (require APC to be degraded)
Cyclins D and E are unstable |
|
|
Term
| Clinical correlates: Because of their central role in promoting cell cycle progression and thereby proliferation, patients with tumors expressing high levels of ______ have a very poor prognosis. |
|
Definition
|
|
Term
| Mitosis is further divided into ____ sub‐phases. |
|
Definition
|
|
Term
| Order of the phases of Mitosis: _____ |
|
Definition
Prophase
prometaphase
metaphase
anaphase
telophase |
|
|
Term
| nuclear membrane breaks down when? |
|
Definition
|
|
Term
| chromosomes begin to decondense and the nuclear membrane begins to reform when? |
|
Definition
|
|
Term
| chromosomes become visible when? |
|
Definition
|
|
Term
| when is there maximally condensed chromosomes pair |
|
Definition
|
|
Term
| centromeres separate when? |
|
Definition
|
|
Term
| ______ is a very useful technique for monitoring cell cycle position. |
|
Definition
|
|
Term
For Flow Cytometry cells are stained with ______ and then passed past a laser in the flow cytometer which in
turn plots the number of cells versus their relative staining (a direct measure of the amount of _____). |
|
Definition
propidium iodide
DNA in a cell |
|
|
Term
| With Flow cytometry and measuring the amound of DNA in a cell the percent of cells ________ approximated |
|
Definition
| in G1, S, and G2/M can be |
|
|
Term
| BrdU is a _______ molecule. |
|
Definition
|
|
Term
| BrdU is a nucleoside analog that incorporates only into the DNA of cells ________. |
|
Definition
| actively replicating their DNA. |
|
|
Term
| BrdU identifies cells in the ____ phase. |
|
Definition
| S (presumably replicating cells) |
|
|
Term
| Meiosis is the process whereby _____ cells are produced from diploid cells. |
|
Definition
|
|
Term
| _____ results in clonal proliferation |
|
Definition
|
|
Term
| During ______, the chromosome complement of offspring cells is halved such that individual cells inherit either the ____ or the ______. |
|
Definition
meiosis I
paternal or maternal copy |
|
|
Term
| ___ different gametes can be generated by meiosis I without recombination. |
|
Definition
|
|
Term
| Meiosis consists of two sequential divisions: Meiosis I (a ____ division) and Meiosis II (an ____ division). |
|
Definition
|
|
Term
| Unlike _____, meiotic prophase I is divided in ____ sub‐phases |
|
Definition
|
|
Term
| Meiosis follows which phase? |
|
Definition
|
|
Term
| Five sub‐phases of meiotic prophase I: _____ |
|
Definition
leptotene
zygotene
pachytene
diplotene
diakinesis |
|
|
Term
| The synaptonemal complex forms when? |
|
Definition
| During zygotene of meiotic prophase I |
|
|
Term
| the nuclear membrane breaks down when during meiosis? |
|
Definition
| diakinesis (subphase of prophase I) |
|
|
Term
| When does the synaptonemal complex dissolve in Meiosis I? |
|
Definition
| diplotene (subphase of prophase I) |
|
|
Term
| homologous chromosomes pair when during Meiosis I? |
|
Definition
| leptotene (subphase of prophase I) |
|
|
Term
| crossing over occurs when in Meiosis I? |
|
Definition
| pachytene (subphase of prophase I) |
|
|
Term
| The pairing of duplicated maternal and paternal chromosomes is called a ______. |
|
Definition
|
|
Term
| crossing over within the bivalent begins dependent upon a structure called the _______ |
|
Definition
|
|
Term
| After synaptonemal complex breaks down during, _____, bivalents are held together by structures called ______. |
|
Definition
|
|
Term
| Meiosis II is similar to ____ cell division and results in the production of ______ in males or ______ in females. |
|
Definition
mitotic
four spermatozoa
1 oocyte and 3 polar bodies |
|
|
Term
| Clinical correlates: Occasionally, chromosome homologues fail to properly segregate during meiosis, a phenomenon called _____, as a result some haploid gametes ______ while others _____. |
|
Definition
non‐disjunction
have no copies of a given chromosome
get two copies. |
|
|
Term
| Clinical correlates: ______ is one of the processes responsible for causing Down syndrome (trisomy 21) |
|
Definition
|
|
Term
| Clinical correlates: the rate of non‐disjunction increases with _____. |
|
Definition
|
|
Term
| Tissues within organisms are composed of at least three general populations of cells: _______ |
|
Definition
1) cells that have permanently exited the cell cycle
2) cells that have temporarily left the cell cycle and are resting but are capable of proliferation
3) cells that constantly and rapidly proliferating. |
|
|
Term
| Terminally differentiated cells are ____ static cell populations that are no longer capable of _____. |
|
Definition
|
|
Term
| Most of our cells in our bodies are ______ with respect to the cell cycle, but are capable of re-entering the cell cycle and proliferating. |
|
Definition
|
|
Term
| Cells that are quiescent (aka G0) may be stimulated by damage or injury to ______. |
|
Definition
| re-enter the cell cycle proliferate, and repair or regenerate damaged tissue. |
|
|
Term
| Examples of populations of cells that are constantly and rapidly renewing: _____ |
|
Definition
| blood cells, dermal fibroblasts, and epithelial cells. |
|
|
Term
| Research has demonstrated that there is a unique relationship between cell growth and the _____ potential of cells. |
|
Definition
|
|
Term
| Under normal conditions, cell division is ____ dependent. |
|
Definition
|
|
Term
| If growth is blocked, cells usually will _____. |
|
Definition
|
|
Term
| resting cells often continue to _____. |
|
Definition
|
|
Term
| frog oocyte can achieve sizes ___ times larger than a typical somatic cell or ___ times larger than a red blood cell. |
|
Definition
|
|
Term
| Because of the absence of a _____ requirement for cell division, embryogenesis is composed of very rapid cell cycles. |
|
Definition
|
|
Term
| The rapid embryonic cell divisions that are growth independent consist almost exclusively of alternating ___ and ___ phases until cells divide below the size of average somatic cells. |
|
Definition
|
|
Term
| _____ cells frequently continue growing throughout life |
|
Definition
|
|
Term
| Clinical correlates: The genetic pathways that link cell growth/size to the cell cycle have integral roles in _______. |
|
Definition
|
|
Term
| there are _____ molecules that alter the rate at which cells grow and divide and even impact their ability to survive. |
|
Definition
|
|
Term
| Mitogens are molecules that ______. |
|
Definition
|
|
Term
|
Definition
|
|
Term
| Mitogens act through _____ to _____ stimulate _______. |
|
Definition
directly
signal transduction pathways
G1/S-phase Cdks |
|
|
Term
| Growth factors increase cell growth and ____ stimulate ______ by promoting the accumulation of ______. |
|
Definition
indirectly
G1/S-phase Cdks
G1/S-cyclins |
|
|
Term
| _____-phase Cdks are like a “gas pedal” in a car. |
|
Definition
|
|
Term
| the INK4 family inhibits cyclin D-Cdk4/6 complexes while the p57, p27, and p21 family inhibits other Cdk complexes function as the _______ |
|
Definition
|
|
Term
| p21 and p27 appear to _____ the _____ complexes |
|
Definition
stimulate
cyclin D-Cdk4/6 |
|
|
Term
| ________ phosphorylate both p21 and p27 to induce their degradation |
|
Definition
| cyclin D-Cdk4/6 complexes |
|
|
Term
| In addition to phosphorylating both p21 and p27 to induce their degradation cyclin D-Cdk4/6 complexes also phosphorylate and inhibit another cell cycle brake called ________. |
|
Definition
| retinoblastoma protein or pRB |
|
|
Term
| pRB functions to _______. |
|
Definition
| represses the transcription of G1/S-phase cyclins |
|
|
Term
| “Restriction point” is the name given to the ____ phase checkpoint. |
|
Definition
|
|
Term
| Checkpoints are a type of molecular _____ that prevents cell cycle progression unless specific criteria are met. |
|
Definition
|
|
Term
| Restriction point involves the activation of G1/S-phase _____ and the inactivation of a wide range of ____ inhibitors as well as inactivation of ____. |
|
Definition
|
|
Term
| Clinical correlates: many proteins involved in _____ can be oncogenic and promote cancer formation |
|
Definition
| activation of cell cycle progression (e.g. cyclin D-Cdk4/6 complexes) |
|
|
Term
| Clinical correlates: many proteins involved in ____ are tumor suppressors and act to prevent cancer. |
|
Definition
| checkpoints (e.g. pRb, p27, etc) |
|
|
Term
| p53 protoncogene or tumor suppressing gene? |
|
Definition
|
|
Term
| The p53 protein is sometimes referred to as the “______” since its overarching function is to prevent cell cycle progression in cells with _____. |
|
Definition
guardian of the genome
damaged DNA |
|
|
Term
| p53 checkpoints of checking whether DNA is damaged can be triggered where? |
|
Definition
| G1/S-phase boundary or the G2/M-phase boundary |
|
|
Term
|
Definition
|
|
Term
| p53 functions as a tetramer and promotes cell cycle ______. |
|
Definition
|
|
Term
| p53 functions as a tetramer and is responsible for initiating _______. |
|
Definition
|
|
Term
| Clinical correlates: ____ is the most frequently mutated gene in cancers. |
|
Definition
|
|
Term
| Loss of p53 function eliminates both _____ & _____ in cancer cells |
|
Definition
| apoptosis and checkpoint arrests |
|
|
Term
| apoptosis is a major means of maintaining tissue cellular _____. |
|
Definition
|
|
Term
| excessive proliferation can be offset via increased ______. |
|
Definition
|
|
Term
| damage induced by: _______ can signal to a cell to undergo apoptosis. |
|
Definition
| radiation, toxins, or free radicals |
|
|
Term
| withdrawal of _____ factors or the presence of specific factors like _____ can induce apoptosis |
|
Definition
|
|
Term
| _____ function is integrally involved in the regulation of apoptosis |
|
Definition
|
|
Term
| In cells undergoing apoptosis, _____ is rapidly released from mitochondrion which in turn triggers a ______. |
|
Definition
cytochrome c
caspase cascade |
|
|
Term
| The end result of the caspase cascade is the activation of “_____” that degrade: ________ |
|
Definition
execution capases
nuclear lamins, DNA, and cytoplasmic proteins. |
|
|
Term
| telltale signs of apoptotic cells in the laboratory include: ______ |
|
Definition
| visualization of DNA regular laddering, TUNEL assays (Tdt-mediated UTP nick end labeling), or cytochrome c release |
|
|
Term
| necrosis is a form of _____ cell death |
|
Definition
|
|
Term
| necrosis is a form of pathological cell death that can be induced by: _______ |
|
Definition
| trauma, loss of nutrients, chemicals, and or viruses. |
|
|
Term
| necrosis results in cells _____ into the local tissue environment this leads to a strong _____ response and potential additional tissue damage. |
|
Definition
swelling until they burst and release cellular contents
inflammatory |
|
|
Term
| _____ is a form of auto-digestion |
|
Definition
|
|
Term
| autophagy is a form of auto-digestion of cells via a vacuole called the _____ that call ultimately result in programmed cell death. |
|
Definition
|
|
Term
| With De novo synthesis of cholesterol the first steps occur in the _____, while the latter steps take place _______. |
|
Definition
cytosol
on the ER membrane. |
|
|
Term
| ________ is the enzyme involved in cholesterol de novo synthesis that is the target of statin drugs and is found where?. |
|
Definition
HMG [3-hydroxy-3-methylglutaryl] Coenzyme A reductase
on the ER membrane |
|
|
Term
| The ER is a major _____ repository |
|
Definition
|
|
Term
| The ER ____ contains various calcium-binding proteins, such as ______ and in muscle cells _______, that allow high levels to be retained until release is needed. |
|
Definition
lumen
calreticulin
calsequestrin in muscle c |
|
|
Term
| The ER ____ contains calcium-releasing channels called ______ that allow calcium to be released into the cytosol upon binding of the second messenger, ____. |
|
Definition
membrane
IP3 receptors
IP3 |
|
|
Term
| Small areas that are devoid of ribosomes are called “transitional ER”, to denote areas such as exit sites and buds that will form ______. |
|
Definition
|
|
Term
| SER predominates in ____ and ______ cells. |
|
Definition
hormone-producing
drug-detoxifying |
|
|
Term
| In muscle cells, the ER is mostly ____ and is given a different name (the ______). |
|
Definition
smooth
sarcoplasmic reticulum, or SR |
|
|
Term
| The smooth ER generates other organelles including: _______ |
|
Definition
| peroxisomes, autophagosomes |
|
|
Term
| Areas of smooth ER (that become cleared of ribosomes, if necessary) accumulate particular ______ and ______ before budding off to form _______. |
|
Definition
cargo (soluble ligands that become concentrated in particular microdomains within the lumen)
and
cargo receptors (transmembrane proteins that bind to—and “trap”—cargo molecules)
peroxisomes |
|
|
Term
| The smooth ER Detoxifies ____ toxins |
|
Definition
|
|
Term
| ______ enzymes of the smooth ER are able to detoxify ingested toxins in hepatocytes, to be excreted as harmless chemicals. |
|
Definition
|
|
Term
| The ER functions in the production of _____ hormones. |
|
Definition
|
|
Term
| The ______ enzymes of the smooth ER begin the further processing of cholesterol into steroid hormones via _____ reactions. |
|
Definition
cytochrome P450
hydroxylation |
|
|
Term
| In muscle cells, the main function of the SER is to ______ for each contraction cycle. |
|
Definition
| sequester and release calcium |
|
|
Term
| The smooth ER is involved in the synthesis of ____ components of lipoprotein particles (mostly in liver cells) |
|
Definition
|
|
Term
| chemicals such as the fungal toxin _____ and ______ (a component of tobacco smoke) become much more potent carcinogens after modification by cytochrome P450 enzymes. |
|
Definition
|
|
Term
| Ribosomes _______ & ______ from the ER membrane constantly. |
|
Definition
| associate and disassociate (DYNAMIC BITCHES) |
|
|
Term
| Ribosomes are structures composed of both _____ & ______. |
|
Definition
|
|
Term
| Ribosomes have a ____ subunit and a _____ subunit. |
|
Definition
|
|
Term
| A “typical” cell may have _____ of ribosomes. |
|
Definition
|
|
Term
| Rough ER predominates in _____ cells. |
|
Definition
| protein-producing (and secreting) |
|
|
Term
| Protein Synthesis always begins where? |
|
Definition
|
|
Term
| After protein translation begins in the cytosol if a signal sequence is translated, then an _____ binds to the complex and temporarily halts translation. |
|
Definition
| SRP (signal recognition particle) |
|
|
Term
| If no signal sequence is translated at the beginning in the cytosol, then the process ________. |
|
Definition
| continues in the cytosol until protein synthesis is complete. |
|
|
Term
| _____ ribosomes are usually found in association with a single mRNA, and are called ________. |
|
Definition
Multiple
polyribosomes or polysomes |
|
|
Term
| If the polysomes are cytosolically located, then the proteins synthesized in this manner will either: ______, _____, or _______ |
|
Definition
reside in the cytosol
be transported to and from the nucleus
or be transported into mitochondria or peroxisomes |
|
|
Term
| Upon docking the SRP on the _____ leaflet of the ER with an SRP receptor and a _____ protein already in the membrane, the SRP detaches and _______. |
|
Definition
cytosolic
translocator
translation resumes |
|
|
Term
| Proteins that are inserted co-translationally into the ER membrane may either be pushed on into the lumen to become _____ proteins or may stay “stuck” in the membrane to become ____ membrane proteins. |
|
Definition
|
|
Term
| Single pass proteins may have ______ facing the cytosolic compartment. |
|
Definition
| either end (N-terminus or C-terminus) |
|
|
Term
| To generate a protein having the N-terminus facing the ER lumen for a single pass protein the presence of _____ downstream of the N-terminal signal sequence is required. |
|
Definition
| an internal stop-transfer sequence |
|
|
Term
| The stop-transfer sequence halts _____ but not _____. |
|
Definition
|
|
Term
| To generate a single pass protein having the N-terminus facing the cytosol , the protein being translated has no _____, but does have an internal ______, which acts similarly to a signal sequence. |
|
Definition
N-terminal signal sequence
start-transfer sequence |
|
|
Term
| The presence of a signal sequence, start-transfer sequences and stop-transfer sequences in the same polypeptide chain allows the cell to generate _____ proteins with various placements of their N- and C-termini |
|
Definition
|
|
Term
| ion channels form “pores” in the membrane by assuming a barrel-like conformation within the membrane, which requires ______ of the polypeptide. |
|
Definition
| multiple passages through the membrane |
|
|
Term
| ER lumen is equivalent to the ______. |
|
Definition
|
|
Term
| ______ cleaves off the signal sequence of proteins that are extruded into the ER lumen |
|
Definition
|
|
Term
| reduced cysteines are oxidized to form intramolecular disulfide bonds by a resident ER protein called _____ in the ER lumen, producing proteins with a significantly different tertiary structure from their initial state. |
|
Definition
| protein disulfide isomerase (PDI) |
|
|
Term
| The ER resident protein ____ acts as a chaperone protein, preventing unfolded proteins from progressing to the Golgi apparatus and helping lumenal proteins to get folded properly. |
|
Definition
|
|
Term
| About half of all eucaryotic proteins are _____. |
|
Definition
|
|
Term
| Almost none of the glycosylated proteins are on the _____ side of the ER. |
|
Definition
| cytosol (BC the lumen is what is equivalent to the ECspace) |
|
|
Term
| glycosylation occurs in the ER for which proteins? |
|
Definition
| both lumenal and transmembrane |
|
|
Term
| A core group of carbohydrate molecules, including:_______ are added in the ER. |
|
Definition
| N-acetylglucosamine, mannose, and glucose, |
|
|
Term
| The calcium-requiring proteins ______ & _____ act as _____ in the ER (much like BiP), by binding to the ____ groups already present on proteins in the ER. |
|
Definition
calnexin and calreticulin
chaperones
carbohydrate |
|
|
Term
| In addition to being a chaperone _____ also functions as a calcium sink, given its high capacity to bind to calcium |
|
Definition
|
|
Term
| Transport vesicles continually bud off from one membrane compartment and fuse with another, carrying both membrane components and soluble molecules (called ____) |
|
Definition
|
|
Term
| Proteins synthesized in the RER but destined for other cellular destinations all head to _______, and then on to ______ and then eventually to the golgi apparatus in a process known as _______. |
|
Definition
ER exit or export sites
vesicular tubular clusters
anterograde trafficking |
|
|
Term
| The exit sites of the RER have _____ |
|
Definition
|
|
Term
| The exit sites of the RER (export sites) become coated with two layers of proteins in what is called a _____ coat |
|
Definition
|
|
Term
| The exit sites of the RER (export sites) concentrate receptors (called ____ receptors) for ____ items that need to travel next to the Golgi apparatus. |
|
Definition
|
|
Term
| cargo receptors are recycled back to? |
|
Definition
|
|
Term
| Some protein, such as ____ & ____ as well as numerous membrane proteins need to stay in the RER. In order to maintain this distribution, they must be re-routed from the VTCs back to the RER. In order to maintain this distribution, they must be re-routed from the VTCs back to the RER. |
|
Definition
|
|
Term
|
Definition
| vesicular tubular clusters |
|
|
Term
| vesicular tubular clusters are a compartment considered to be _____ of the RER |
|
Definition
|
|
Term
| The _____ coat forces vesicles to bud off of the ___ and go back to the RER. |
|
Definition
COPI
VTC (vesicular tubular clusters) |
|
|
Term
| Retrograde trafficking, and is facilitated by ____ and the ____-end directed motor _____. |
|
Definition
|
|
Term
For RER and Golgi:
Anterograde trafficking = COP_ coats and ____ motors. |
|
Definition
|
|
Term
For RER and Golgi:
Retrograde trafficking = COP__ coats and ____ motors. |
|
Definition
|
|
Term
| Vesicular Tubular Clusters are vesicles that, once free of their COP__ coats, begin to fuse to form the irregular looking tubules that give this compartment its name. |
|
Definition
|
|
Term
| Vesicular Tubular Clusters contain membrane and lumenal contents destined for the ______, but also membrane and lumenal material that must be _______. |
|
Definition
Golgi apparatus
returned to the ER. |
|
|
Term
| Soon after losing their ____ coats, some Vesicular Tubular Clusters acquire ____ coats in order to sort material destined for the Golgi from material that needs to go back to the RER. |
|
Definition
|
|
Term
| Vesicular Tubular Clusters function in the Retrieval of ER resident molecules by the budding off of ______. |
|
Definition
|
|
Term
| cis Golgi network (CGN). function |
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
| trans Golgi network (TGN) function |
|
Definition
|
|
Term
| The Golgi, like the ER is also associated with the ______ network |
|
Definition
|
|
Term
| Golgi membrane proteins interact with the MT motor _____, which helps maintain the Golgi near the ______, which in turn is located close to the nucleus in most cell types. |
|
Definition
|
|
Term
| If ______ is inhibited or if _____ are disassembled, the Golgi apparatus “disappears” into randomly located tubules and sacs |
|
Definition
|
|
Term
| Golgi Apparatus functions in the Synthesis of _______. |
|
Definition
|
|
Term
| Processing of proteins and lipids that arrive from the ER includes _____ion, _____ion, ______ion by the Golgi. |
|
Definition
Sulfation
Hydroxylation
Glycosylation |
|
|
Term
| The golgi assembles protein ____ into larger structures |
|
Definition
|
|
Term
| Most of the processing occurs in the _____ of the Golgi, while sorting occurs mostly in the _______. |
|
Definition
Golgi cisternae
cis- and trans-Golgi networks |
|
|
Term
| Because ______ is compartmentalized within the Golgi, we can use the presence of _______ as markers for those compartments. |
|
Definition
processing
processing enzymes |
|
|
Term
| we can define specific regions of the Golgi either by enzyme _____ or _____ techniques on the processing enzymes. |
|
Definition
| cytochemistry or immunocytochemistry |
|
|
Term
| For the secretory route off the Golgi, some area buds off,sometimes using a ____ machinery, associates with microtubules and ____ motors, and heads to the cell periphery as a secretory vesicle |
|
Definition
|
|
Term
| Instead of going the secretory route from the Golgi, it can either lead to ______ or _____ formation. |
|
Definition
Peroxisome formation.
Late endosomes (and eventual lysosome formation). |
|
|
Term
| What results in cystic fibrosis? |
|
Definition
| Because of the quality control mechanisms present in the ER, chloride transporter molecules with mild mutations are kept in the ER and eventually degraded in the cytosol instead of being transported to the plasma membrane, even though they would function normally. |
|
|
Term
| I-cell disease results from aberrant processing of _____ in the cis-Golgi network causing their _____ instead of _______. |
|
Definition
lysosomal hydrolases
secretion
incorporation into lysosomes |
|
|
Term
| Four important processes for successful vesicular transport: _______ |
|
Definition
Formation of transport vesicle
Inclusion of appropriate molecules in the vesicle lumen
Inclusion of correct “packaging” info. for appropriate target destination.
Successful docking and fusion upon arrival at destination |
|
|
Term
| _____, _____, & _____ proteins allow vesicles to fuse only with appropriate target membranes. |
|
Definition
| rabs, SNARE proteins, and tethering |
|
|
Term
| v-SNARES are used for __________ |
|
Definition
| close-range docking and fusion |
|
|
Term
| t-SNARES are used for _______ |
|
Definition
| close-range docking and fusion) |
|
|
Term
| tethering proteins are used for _______ |
|
Definition
| longer-range recognition and vesicle attachment |
|
|
Term
| rabs are ______ proteins. |
|
Definition
|
|
Term
| G-proteins (rabs) are used for ______ |
|
Definition
| activation of various stages of the process of vesicular transport |
|
|
Term
| V-snare binds with ______. |
|
Definition
|
|
Term
| where is the t-snare located? |
|
Definition
|
|
Term
| where is the v-snare located? |
|
Definition
|
|
Term
| The rab protein binds to the ______. |
|
Definition
|
|
Term
| tethering protein is located where? |
|
Definition
|
|
Term
| the rab protein is located where? |
|
Definition
|
|
Term
| Cells collect material from their environment using: _______ |
|
Definition
Pinocytosis.
Receptor-mediated endocytosis.
Caveolin-mediated endocytosis (and transcytosis).
Phagocytosis. |
|
|
Term
| SNARE complexes are disassembled using _______ complex. |
|
Definition
|
|
Term
| Uptake of extracellular materials is called? |
|
Definition
|
|
Term
| Pinocytosis provides a cell a way to ingest fluid and other macromolecules _______. |
|
Definition
|
|
Term
| Does Pinocytosis involve coated or uncoated |
|
Definition
|
|
Term
| In ______, large amounts of plasma membrane are continuously ingested through Pinocytosis |
|
Definition
|
|
Term
| _________ is accomplished by coordination of endocytosis and exocytosis. |
|
Definition
|
|
Term
| In "receptor-mediated endocytosis", Integral membrane proteins on the plasma membrane called “______” become occupied with molecules called ______ on their extracellular surfaces. |
|
Definition
|
|
Term
| In “receptor-mediated endocytosis”, Ligand occupancy of the Cargo Receptor recruits intracellular _____ proteins to bind to the _____ side of the cargo receptor. |
|
Definition
|
|
Term
| first layer of the “coat” in "receptor-mediated endocytosis" is formed by ______ |
|
Definition
|
|
Term
| The presence of adaptins stimulates the recruitment of _____ molecules to the adaptins, in the form of _____, to form the ____ layer of the coat. |
|
Definition
clathrin
triskelions
second |
|
|
Term
| The ____-assembly of clathrin triskelions into a basketlike network induces curvature of the membrane, and thus _____ formation. |
|
Definition
|
|
Term
| Towards the end of "receptor-mediated endocytosis", the protein ____ wraps around the stalk, and along with other recruited proteins, squeezes the two closely apposed membranes together until the outer leaflets fuse. |
|
Definition
|
|
Term
| Is specific or non specific material captured in "receptor-mediated endocytosis" |
|
Definition
|
|
Term
| Once the vesicle is formed in "receptor-mediated endocytosis", the clathrin coat quickly ______ (___-dependent) |
|
Definition
|
|
Term
| Receptor-mediated endocytosis provides a way to ________ for cell entry so that huge volumes of fluid do not need to be ingested in order to acquire nutrients (LDL particles) or to start a signalling cascade (proliferation factors like EGF). |
|
Definition
| concentrate dilute ligands |
|
|
Term
| Mutations in the gene encoding the ______ cause accumulation of LDL in the blood, leading to ______ and, generally, premature mortality. |
|
Definition
LDL receptor
atherosclerosis |
|
|
Term
| Caveolin-mediated endocytosis has _____ protein caveolin instead of having the ______ protein clathrin on their cytoplasmic surfaces as in "receptor mediated endocytosis". |
|
Definition
integral membrane
peripheral membrane |
|
|
Term
| caveolin is most often associated with _____. |
|
Definition
|
|
Term
| Caveolin-mediated endocytosis can form vesicles called _______. |
|
Definition
|
|
Term
| Caveolin-mediated endocytosis can form vesicles called caveolae, which can be transported to the ______ at other parts of the cell in a process known as ______. |
|
Definition
|
|
Term
| In vascular endothelial cells caveolae can pass completely through the cytoplasm to fuse with the plasma membrane at the opposite end of the cell, allowing for ______ across the cell. |
|
Definition
|
|
Term
| Phagocytosis is mediated by _______. |
|
Definition
|
|
Term
| Phagocytosis has _____ pits. |
|
Definition
|
|
Term
| Phagocytosis involves the uptake of large particles such as bacteria, old red blood cells, and cell debris into _____. |
|
Definition
|
|
Term
| Phagosomes then fuse with _____. |
|
Definition
|
|
Term
| Phagocytosis is generally limited to a few specialized cell types such as _____ & ______. |
|
Definition
| macrophages and neutrophils. |
|
|
Term
| Phagocytosis functions in _____ & _____. |
|
Definition
|
|
Term
| Phagocytosis functions in the recycling of ______. |
|
Definition
| components of dead or senescent cells. |
|
|
Term
| Post-Endocytic Compartments: _____ |
|
Definition
Early endosome compartment
Multivesicular body compartment
Late endosome compartment
Lysosomal compartment |
|
|
Term
| Which Post-Endocytic Compartment is found closest to the PM? |
|
Definition
| Early endosome compartment |
|
|
Term
| A _____ compartment is between early and late endosomes |
|
Definition
| Multivesicular body compartment |
|
|
Term
| Late endosome compartment is found? |
|
Definition
|
|
Term
| For all the Post-Endocytic Compartments the vesicles possess proteins on their outer surfaces called ____ that allow them to recognize the appropriate target compartments with which to fuse. |
|
Definition
|
|
Term
| What is the First intracellular membrane compartment that endocytosed vesicles encounter? |
|
Definition
| Early endosome compartment |
|
|
Term
| After ____ coat is lost, the vesicles fuse with early endosomes. |
|
Definition
|
|
Term
| After the vesicles fuse with early endosomes, _____ of vesicle contents occurs. |
|
Definition
|
|
Term
| the endosome membrane has ______, in order to keep the lumen ______. |
|
Definition
proton pumps
acidic (~pH 6.0-6.5). |
|
|
Term
| Because the endosome lumen is acidic (~pH 6.0-6.5), this causes the ____ and _____ to fall apart of the endocytosed vesicle. |
|
Definition
|
|
Term
| After the ligand and receptor have dissociated post fusion with the endosome, When they dissociate, the transmembrane receptors are ______, while the ligand ______. |
|
Definition
redirected to the plasma membrane
remains in the endosome |
|
|
Term
| Most of the luminal contents of the early endosome are destined for the next compartment, the _______. |
|
Definition
|
|
Term
| Multivesicular bodies are merely a _____ that matures after formation |
|
Definition
|
|
Term
| Multivesicular bodies travel along _____ and use ____ as their motor protein. |
|
Definition
|
|
Term
| Multivesicular bodies, begin as ______ and are induced to invaginate to form _______. |
|
Definition
early endosome membranes
intralumenal vesicles (ILVs) |
|
|
Term
| Multivesicular bodies Begin as early endosome membranes are induced to invaginate to form intralumenal vesicles (ILVs). Next, larger vesicles containing the ILVs bud off and travel to deeper parts of the cell, maturing along the way by acquiring new membrane proteins. Finally, they reach the _____ compartment and become part of it. |
|
Definition
|
|
Term
| Vesicles are transported from the multivesicular bodies to the _____ |
|
Definition
|
|
Term
| late endosomes have an internal pH of? |
|
Definition
|
|
Term
| Early endosomes have an internal pH of? |
|
Definition
|
|
Term
| After becoming part of the late endosome compartment, the contents are again resorted. Some vesicles will pinch off, together with hydrolytic enzymes, to become ______. |
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
| All cells must balance _____ of membrane with ____ of the plasma membrane. |
|
Definition
|
|
Term
| Some membrane gets recycled from early ______, but most derives from the _______ |
|
Definition
endosomes
protein synthesis/packaging pathway |
|
|
Term
| the simplest route of membrane recycling involves? |
|
Definition
|
|
Term
| In Constitutive pathway of secretion, vesicles are continuously formed at the _____ of the Golgi (usually using _____), bud off from the Golgi using _____, and diffuse to the cell surface, where they fuse with the plasma membrane. |
|
Definition
trans face
clathrin coats
dynamin |
|
|
Term
| Secretion involves transport along _____, using the motor protein ____, and when it reaches the cell cortex, transport through the dense ___ web using the ____-based motor protein _____. |
|
Definition
microtubules
kinesin
actin
actin
myosin |
|
|
Term
| Vesicles of the Constitutive pathway of secretion carry both proteins to be ____ and _____ proteins. |
|
Definition
secreted
integral membrane |
|
|
Term
| ______ of secretion is necessary for maintenance of the composition of the plasma membrane and replenishment of components, and occurs in all cells. |
|
Definition
|
|
Term
| Regulated pathway of secretion is? |
|
Definition
| Some products processed by the Golgi are concentrated and stored in vesicles that are only released in response to a specific extracellular signal. |
|
|
Term
| ____ transport requires no energy. |
|
Definition
|
|
Term
| Two kinds of transport mechanisms for passive: _____ |
|
Definition
| channels and carrier proteins. |
|
|
Term
|
Definition
Voltage-gated
Ligand-gated
Mechanically gated
Ungated channels |
|
|
Term
| Channels are pore-like openings made by transmembrane proteins or groups of proteins, which passively let ____ flow ________ |
|
Definition
ions
down their concentration gradients |
|
|
Term
| With Voltage-gated, _____ opens the channel. |
|
Definition
| Membrane depolarization opens the channel |
|
|
Term
| With Ligand-gated, _____ opens the channel. |
|
Definition
| Binding of a ligand opens the channel. |
|
|
Term
| With Mechanically gated, _____ opens the channel. |
|
Definition
| movement of membrane specializations called stereocilia opens the channel |
|
|
Term
| Carrier proteins are transmembrane proteins that take one or a few ___ molecules on the outside of the membrane, and through a _____ in the protein, release the ions on the cytoplasmic side. |
|
Definition
ion
conformational change |
|
|
Term
| ____ proteins can be either passive or active. |
|
Definition
|
|
Term
| What is faster channels or carriers? |
|
Definition
| Channels are much faster than carriers |
|
|
Term
| Types of Carrier proteins |
|
Definition
Uniport
Coupled- (Symport & Antiport) |
|
|
Term
| ____ carrier proteins involve the transport of one type of molecule in only one direction |
|
Definition
|
|
Term
| With Coupled carrier proteins, _____ molecules are involved. |
|
Definition
|
|
Term
| _____ carrier proteins the different molecules both pass through the membrane in the same direction. |
|
Definition
|
|
Term
| with _____ carrier proteins The different molecules pass through the membrane in opposite directions (one travels into the cell, the other travels outward) |
|
Definition
|
|
Term
| ______-gated ____ & _____ channels that are responsible for the electrical excitability of neuron and muscle cell membranes are examples of passive transporters. |
|
Definition
|
|
Term
| The ______ is an energy requiring "pump" that maintains the intracellular ionic balance. |
|
Definition
|
|
Term
| Up to one third of total cellular energy may be devoted to operating ________. |
|
Definition
| Na+/K+ ATPase pump (active transport) |
|
|
Term
| Lysosomes are organelles possessing a _____ membrane that contain at least 40 ______. |
|
Definition
|
|
Term
| Lysosomes can digest most ______. |
|
Definition
|
|
Term
| the hydrolases of Lysosomes are heavily ______. |
|
Definition
|
|
Term
| lysosomal membranes contain a modified phospholipid called _______, which resists degradation. |
|
Definition
| bis(monoacylglycero)phosphate, also called lysobisphosphatidic acid |
|
|
Term
| can lyosomes be observed as stained objects by light microscopy? |
|
Definition
|
|
Term
| ______ activity can be used to identify lysosomes more readily. |
|
Definition
| acid phosphatase activity |
|
|
Term
| Lysosomal membranes contain proton pumps to acidify the interior as well as _______ which are important for autophagic events, and various carrier proteins that transport digested molecules to the cytoplasm for their reuse. |
|
Definition
| Lysosome-Associated Membrane Proteins (LAMPs, for short) |
|
|
Term
| Structural Variants of lysosomes: ______ |
|
Definition
Primary lysosomes
Secondary lysosomes
Residual bodies |
|
|
Term
| Primary lysosomes are those that appear ____ by electron microscopy, and may represent organelles that are not “visibly” _______. |
|
Definition
homogeneous
engaged in digestion. |
|
|
Term
| Primary lysosomes with larger diameters are found in ___ cells such as neutrophils and macrophages. |
|
Definition
|
|
Term
| Secondary lysosomes with EM show some _______ and are _____ engaged in the digestion of materials. |
|
Definition
sub-structure (both light and dark gray areas)
actively |
|
|
Term
| The interiors are very acidic (~ pH 5) of ____ lysosomes. |
|
Definition
|
|
Term
| Residual bodies are structures that contain ____ material (mostly _____). |
|
Definition
|
|
Term
| There are _____ areas as well as the light and dark gray areas found in secondary lysosomes in Residual bodies. |
|
Definition
|
|
Term
| In some long-lived cell types (such as neurons or cardiac myocytes) large quantities of residual bodies accumulate and are called _____. |
|
Definition
|
|
Term
| Lysosomal enzymes are made in the _____. |
|
Definition
|
|
Term
| Lysosomal enzymes are made in the RER, are further processed in the ______ (where they acquire ______ moieties) |
|
Definition
cis Golgi network
mannose-6-phosphate |
|
|
Term
| Lysosomal enzymes are made in the RER, are further processed in the cis Golgi network (where they acquire mannose-6-phosphate moieties) and accumulate in the ______ in places that are enriched with _______, which they bind to. |
|
Definition
trans-Golgi network
mannose-6-phosphate receptors |
|
|
Term
| On the cytoplasmic side of the TGN where the lysosomal enzymes have accumulated there is an accumulation of ______ & ______, allowing the vesicle to bud off the TGN using _____. |
|
Definition
adaptins (called AP-1)
clathrin coats
dynamin |
|
|
Term
| After the Lysosomal enzyme filled vesicles bud off the TGN they immediately lose their ______, and then fuse with _____, where sorting of the contents occurs. |
|
Definition
clathrin coats
late endosomes |
|
|
Term
| In the acidic environment of the late endosomes, the Lysosomal enzymes are released from their ____ and are then ____ so that they can no longer re-bind. |
|
Definition
receptors
dephosphorylated |
|
|
Term
| After breaking from their receptors and be dephosphorylated in the late endosomes, the lysosomal enzymes are packaged into new vesicles, the ________. |
|
Definition
| lysosomes (primary lysosomes). |
|
|
Term
| Part of the functional definition of a lysosome is that it lacks _____ in its membrane. |
|
Definition
|
|
Term
| The Man-6-P receptors aggregate and pinch off the late endosomes into return vesicles after their cytosolic domains are bound by a multi-subunit complex called _____ so that they can return to the _____ for recycling. |
|
Definition
|
|
Term
| Lysosomes function in the degradation of components acquired from ________ |
|
Definition
| late endosomes (what was left over and not recycled back) |
|
|
Term
| Lysosomes function in the degradation of ______(in some cell types such as macrophages). |
|
Definition
|
|
Term
| In phagocytic cells such as macrophages, the membrane-enclosed object generated by phagocytosis (______) fuses with a lysosome to generate a ______, where lysosomal enzymes digest the foreign particles that were endocytosed. |
|
Definition
|
|
Term
| Lysosomes function in the Degradation of _______(all cells) |
|
Definition
|
|
Term
| Degradation of autophagosomes by Lysosomes accomplishes the turnover of older and/or dysfunctional ______. |
|
Definition
|
|
Term
| Digestion of cellular macromolecules occurs in ______ through _______. |
|
Definition
| lysosomes (autophagosomes) |
|
|
Term
| Macroautophagy is important during _____, as a part of the _____ pathway. |
|
Definition
|
|
Term
| Macroautophagy is under _____ regulation |
|
Definition
|
|
Term
| Macroautophagy is under tight regulation, via several ______ pathways. |
|
Definition
|
|
Term
| Microautophagy small parts of the _____ extend outward, grab a bit of the cytoplasm, internalize it, and digest the contents. |
|
Definition
|
|
Term
| Chaperone-mediated autophagy involves docking of unfolded proteins at the lysosomal membrane at specific receptors ____ passing through a membrane channel, and then becoming digested. |
|
Definition
|
|
Term
| Lysosomal enzymes have optimal activity at _____. |
|
Definition
|
|
Term
| Lysosomes have membrane proton pumps that decrease the interior pH to ____, |
|
Definition
|
|
Term
| Normally, proteins found in the cytoplasm are protected from lysosomal digestion by two means: |
|
Definition
| 1) the membrane surrounding the lysosomal enzymes, and 2) the cytoplasmic pH (~7.2), which inactivates the acid hydrolases. |
|
|
Term
|
Definition
|
|
Term
| With Lysosomal Storage Diseases the causative agent may be that theres deficits in the trafficking of that enzyme (_____ disease) |
|
Definition
|
|
Term
| Hurler's syndrome is a defect in the enzyme _______, an enzyme involved in the turnover of ________(an abundant macromolecular component of______). |
|
Definition
αL-iduronidase
glycosaminoglycans
connective tissue |
|
|
Term
| With Hurler's syndrome, Patients suffer: ________ |
|
Definition
| mental retardation, skeletal deformities, and cardiac malfunction due to arterial occlusion. |
|
|
Term
| Tay Sachs is a defect in ________, which breaks down ______ called ______. |
|
Definition
hexosaminidase A
membrane glycolipids
gangliosides |
|
|
Term
| In Tay Sachs The clinical problems are most significant in the nervous system because that is where the concentration of ____ is highest, although most cell types are involved. |
|
Definition
|
|
Term
| In I-cell disease the ______ information in the Golgi is lost, so that the enzymes do not acquire ______ moieties and are lost to the _______ via the ______ pathway. |
|
Definition
targeting
mannose-6-phosphate
extracellular matrix
constitutive secretory |
|
|
Term
| In I-cell disease lysosomes form but are _______, showing “_____” by TEM. |
|
Definition
devoid of luminal content
lysosomal ghosts |
|
|
Term
| Current clinical procedures for Lysosomal Storage Diseases include ____ & _____ therapies, but each have significant limitations. |
|
Definition
| enzyme-replacement and pharmacological chaperone |
|
|
Term
| During Starvation or malnutrition, ____ allows the cell to survive by digesting part of itself. Under these conditions, the ____ surface area can increase by ~10x. |
|
Definition
Macroautophagy
autophagic |
|
|
Term
| During various muscle wasting diseases (muscular dystrophies) and neurodegenerative processes (Parkinson’s, Alzheimer’s, and prion diseases) the cells die due to excessive loss of _____ via _____-. |
|
Definition
organelles
macroautophagy |
|
|
Term
| Macroautophagy may assist growing tumors (which, early on, have _____ cores) by allowing the cells in the center to ________. |
|
Definition
avascular
survive until vascularization occurs |
|
|
Term
| "Cellular woodchipper" (_______) |
|
Definition
|
|
Term
| *The proteasomal machinery involves nearly ___ of total celllular protein. |
|
Definition
|
|
Term
| The proteasomal machinery also involves over ____ gene products. (______ identified by sequence homology). |
|
Definition
|
|
Term
| Proteasomes requires ______. |
|
Definition
|
|
Term
| _____ (of particular ____) leads to the proteasome pathway, while ______ provides a signal for that protein to be broken down in the lysosome (and also for “normal” signal transduction pathways). |
|
Definition
Poly-ubiquitination
lysines
mono-ubiquitination |
|
|
Term
| Proteasomes possesses a central,____, with the active sites of various degradative enzymes facing the _____. |
|
Definition
hollow cylindrical core
lumen |
|
|
Term
| There is a ___ on each end of the cylinder of Proteasomes. |
|
Definition
|
|
Term
| There are ___ activating and conjugating components present in Proteasomes. |
|
Definition
|
|
Term
| Proteasomes are found in the: ______ in eukaryotes; homologues found in E. coli. |
|
Definition
| nucleus, cytoplasm and mitochondria |
|
|
Term
| Proteins destined for destruction (usually, but not always) become tagged with _____ of the small molecule called ubiquitin, via the activity of a _____. |
|
Definition
ubiquitin ligase
multiples |
|
|
Term
| A _______ protein (E1) activates ubiquitin in an ATP-requiring step, forming a high-energy ____ bond. |
|
Definition
ubiquitin-activating
thiol-ester bond |
|
|
Term
| A ubiquitin-activating protein (E1) activates ubiquitin in an ATP-requiring step. Forms high-energy thiol-ester bond. It then conjugates ubiquitin to an ___ protein, which hands it off to an E3 ligase (_____). |
|
Definition
|
|
Term
| A ubiquitin-activating protein (E1) activates ubiquitin in an ATP-requiring step. Forms high-energy thiol-ester bond. It then conjugates ubiquitin to an E2 protein, which hands it off to an E3 ligase (ubiquitin ligase), which adds ubiquitin subunits to ____ of a so-called “_____” on the substrate protein. Occurs _____ times. |
|
Definition
lysines
degradation site
multiple |
|
|
Term
| Degradation signals include sites on _____ or _____ proteins, _____ or ____ amino acids. |
|
Definition
misfolded or denatured proteins
oxidized or abnormal |
|
|
Term
| A degradation site may be generated by a single cleavage event which produces a ______. The “____ rule”. |
|
Definition
destabilizing N-terminus
N-End Rule |
|
|
Term
| There are many (>1,000) ubiquitin ____ in cells, each with the ability to recognize a specific _____ sequence. |
|
Definition
|
|
Term
| Proteasomes are aided by ___ proteins |
|
Definition
|
|
Term
| The _____ of the proteasome selectively recognizes and allows the ubiquitin-tagged proteins to enter the cylinder. |
|
Definition
|
|
Term
| The end-cap of the proteasome ____ the protein and presents it to the proteases inside. |
|
Definition
|
|
Term
| The end-cap of the proteasome uses at least ___ ATP molecules. |
|
Definition
|
|
Term
| _______ is an important regulatory step for proteasomes, because the proteases inside the core are proteases inside the core are ______. |
|
Definition
end-cap of the proteasome selectively recognizes
non-specific. |
|
|
Term
| Recognition and admission into the core (in other words, ___ selectivity) occurs at the “___” of the proteasome. |
|
Definition
|
|
Term
| A battery of ____ located in the central cylinder of a proteasome degrade proteins into small peptides. |
|
Definition
|
|
Term
| In a few cases, a large ____ is cleaved into a functional protein by proteasomes |
|
Definition
|
|
Term
| Cytosolic enzymes finish the job of proteosomes by _______ |
|
Definition
| reducing the short peptides to single amino acids. |
|
|
Term
| De-ubiquitinating enzymes exist where? |
|
Definition
|
|
Term
| Proteosomes function in the degradation or turnover of ____-lived proteins |
|
Definition
|
|
Term
| Proteosomes function in the “____” of errors in transcription or translation. Possibly as much as 30% of _____ proteins are quickly degraded. |
|
Definition
|
|
Term
| Proteosomes function in the degradation of specific proteins at particular _____ times. |
|
Definition
|
|
Term
| Example of Proteosomes degrading specific proteins at particular cell-cycle times |
|
Definition
| cyclin B by the Anaphase Promoting Complex/cyclosome (or APC/C) |
|
|
Term
| Proteosomes function in the degradation of ______ proteins |
|
Definition
|
|
Term
| Proteosomes function in the removal of _____ damaged proteins. |
|
Definition
|
|
Term
| Proteosomes function in the activation of ______. |
|
Definition
| transcriptional regulators |
|
|
Term
| Example of Proteosomes functioning in the activation of transcriptional regulators? |
|
Definition
| NFκB is made as a 100 kDa precursor. After it exits the proteasome, it is a functional, 50-52 kDa protein. |
|
|
Term
| Faulty ubiquitination system results in the ________. |
|
Definition
| accumulation of proteins in the cytosol |
|
|
Term
| Cancer can result from stabilized and/or elevated ____ levels, or destabilization of ______ proteins, all due to faulty ______ system. |
|
Definition
oncogene
tumor suppressor
ubiquitination |
|
|
Term
| Proteosomes disorders are primarily _____ disorders |
|
Definition
| neurological degenerative (Huntington’s disease and Alzheimer’s) |
|
|
Term
| Proteins overexpressed due to invasion of ____ virus may result in the accelerated ____ of important proteins. |
|
Definition
|
|
Term
|
Definition
| Small ubiquitin-like modifier proteins |
|
|
Term
| SUMO (Small ubiquitin-like modifier) proteins are similiar in mechanism to _______, but don’t usually send material to the _______. |
|
Definition
ubiquitin (E1-, E2-, and E3-like proteins)
cellular garbage dump |
|
|
Term
| SUMO (Small ubiquitin-like modifier) proteins may influence ____ pathways or transport of molecules into the _____. |
|
Definition
signal transduction
nucleus |
|
|
Term
| A degradation site may be generated by a single cleavage event which produces a ______. The “____ rule”. |
|
Definition
destabilizing N-terminus
N-End Rule |
|
|
Term
| There are many (>1,000) ubiquitin ____ in cells, each with the ability to recognize a specific _____ sequence. |
|
Definition
|
|
Term
| Proteasomes are aided by ___ proteins |
|
Definition
|
|
Term
| The _____ of the proteasome selectively recognizes and allows the ubiquitin-tagged proteins to enter the cylinder. |
|
Definition
|
|
Term
| The end-cap of the proteasome ____ the protein and presents it to the proteases inside. |
|
Definition
|
|
Term
| The end-cap of the proteasome uses at least ___ ATP molecules. |
|
Definition
|
|
Term
| _______ is an important regulatory step for proteasomes, because the proteases inside the core are proteases inside the core are ______. |
|
Definition
end-cap of the proteasome selectively recognizes
non-specific. |
|
|
Term
| Recognition and admission into the core (in other words, ___ selectivity) occurs at the “___” of the proteasome. |
|
Definition
|
|
Term
| A battery of ____ located in the central cylinder of a proteasome degrade proteins into small peptides. |
|
Definition
|
|
Term
| In a few cases, a large ____ is cleaved into a functional protein by proteasomes |
|
Definition
|
|
Term
| Cytosolic enzymes finish the job of proteosomes by _______ |
|
Definition
| reducing the short peptides to single amino acids. |
|
|
Term
| De-ubiquitinating enzymes exist where? |
|
Definition
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Term
| Proteosomes function in the degradation or turnover of ____-lived proteins |
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Definition
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Term
| Proteosomes function in the “____” of errors in transcription or translation. Possibly as much as 30% of _____ proteins are quickly degraded. |
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Definition
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Term
| Proteosomes function in the degradation of specific proteins at particular _____ times. |
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Definition
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Term
| Example of Proteosomes degrading specific proteins at particular cell-cycle times |
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Definition
| cyclin B by the Anaphase Promoting Complex/cyclosome (or APC/C) |
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Term
| Proteosomes function in the degradation of ______ proteins |
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Definition
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Term
| Proteosomes function in the removal of _____ damaged proteins. |
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Definition
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Term
| Proteosomes function in the activation of ______. |
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Definition
| transcriptional regulators |
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Term
| Example of Proteosomes functioning in the activation of transcriptional regulators? |
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Definition
| NFκB is made as a 100 kDa precursor. After it exits the proteasome, it is a functional, 50-52 kDa protein. |
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Term
| Faulty ubiquitination system results in the ________. |
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Definition
| accumulation of proteins in the cytosol |
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Term
| Cancer can result from stabilized and/or elevated ____ levels, or destabilization of ______ proteins, all due to faulty ______ system. |
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Definition
oncogene
tumor suppressor
ubiquitination |
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Term
| Proteosomes disorders are primarily _____ disorders |
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Definition
| neurological degenerative (Huntington’s disease and Alzheimer’s) |
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Term
| Proteins overexpressed due to invasion of ____ virus may result in the accelerated ____ of important proteins. |
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Definition
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Term
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Definition
| Small ubiquitin-like modifier proteins |
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Term
| SUMO (Small ubiquitin-like modifier) proteins are similiar in mechanism to _______, but don’t usually send material to the _______. |
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Definition
ubiquitin (E1-, E2-, and E3-like proteins)
cellular garbage dump |
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Term
| SUMO (Small ubiquitin-like modifier) proteins may influence ____ pathways or transport of molecules into the _____. |
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Definition
signal transduction
nucleus |
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