Term
|
Definition
| special PROTEIN found in the MEMBRANE as a CHANNEL for H2O to flow through |
|
|
Term
|
Definition
|
|
Term
|
Definition
a prok bacteria that grows best at cold temps
grows on food in fridge |
|
|
Term
|
Definition
| prok bacteria that grows best at medium temps. responsible for some human infections. |
|
|
Term
|
Definition
prok bacteria that grows best at hot temps.
bacteria that is in hot springs |
|
|
Term
|
Definition
| refers to info that cells pass to progeny cells, but is not carried in the sequence of DNA |
|
|
Term
|
Definition
| covalent linkage which joins a fatty acid to the glycerol backbone for a phospholipid |
|
|
Term
|
Definition
| the evolutionary theory that mitochondria arose due to the swallowing of one prok by another |
|
|
Term
| 3 ways in which an ion channel can be gated |
|
Definition
VLT
voltage
ligand binding
temperature |
|
|
Term
|
Definition
| the MEMBRANE that is contiguous with the ER membrane |
|
|
Term
|
Definition
|
|
Term
| which membrane is thicker? Gram (-) or (+) |
|
Definition
|
|
Term
| are GRAM (-) and (+) prok or euk? |
|
Definition
|
|
Term
| which control cheek cell from lab would contain more purple color? |
|
Definition
| the (+) control cheek cell |
|
|
Term
| which has the greater pH? mito or lyso? |
|
Definition
|
|
Term
| what do all cells have/are bound by? |
|
Definition
| lipid bilayer with proteins |
|
|
Term
| which is simplier? unicellular or multicellular? |
|
Definition
|
|
Term
| multicellular cells cannot reproduce. if they do, they can cause ______. |
|
Definition
|
|
Term
|
Definition
Plasma Membrane: protects cells, control systems to import/export out of cell.
Cellular compartment construct from food sources
DNA/RNA |
|
|
Term
|
Definition
membrane which contains hydroPHOBIC tails in the middle and hydroPHILIC heads on either side.
has a macromolecular structure and is built from lipids |
|
|
Term
| what is one place in which an aqueous environment is found? |
|
Definition
lipid bilayer.
h.phobic tails agitate causing non-ionic center. similar to a drop of oil in H2O. |
|
|
Term
| L. Bilayer is permeable to ______, but not to _______. |
|
Definition
|
|
Term
| what causes osmotic pressure? |
|
Definition
| ionic differences on either side |
|
|
Term
|
Definition
|
|
Term
| what does the production of cells require? |
|
Definition
| division of preexisting cells |
|
|
Term
| what does a cell membrane contain? |
|
Definition
phospholipid bilayer, proteins, sugar chains attached to proteins/lipids.
somewhat permeable to water, not to ions. |
|
|
Term
|
Definition
something that is both water loving and water hating.
example: lipid bilayer. hydrophob and philic. triglycerides are NOT amphipathic. have fatty R groups. |
|
|
Term
| 3 minimal features of a cell: |
|
Definition
1. membrane
2. genome
3. information transfer |
|
|
Term
| how many cellular compartments do proks contain? |
|
Definition
| 1. unless you count the compartments b/t the cell membrane and cell walls |
|
|
Term
| what two kingdoms are contained in proks? also, are they uni or multi cellular? |
|
Definition
archea and bacteria
they are both unicellular |
|
|
Term
| which prok kingdom is able to live in extreme environments? |
|
Definition
|
|
Term
| what does the cell wall of PROKS do, and what two groups is it divided into? |
|
Definition
1. gram (-)cells have THIN walls and additional OUTER MEMBRANE
2. gram (+) cells have thick walls and plasma membrane |
|
|
Term
| which cell wall is thicker gram (-) or (+). also what additions do they each contain? |
|
Definition
thickest is positively the (+) wall. in addition to the plasma membrane.
(-) is addition to the outer membrane |
|
|
Term
| who were gram (+) and (-) cell walls named after? |
|
Definition
| Sir Hans Christian Graham |
|
|
Term
| at the molecular lever, what kingdom the components of archea most similar to? |
|
Definition
|
|
Term
| what are the largest and smallest cells? |
|
Definition
|
|
Term
| can proks or euks live under various environments? |
|
Definition
|
|
Term
|
Definition
| grow best at a pH BELOW 7 |
|
|
Term
|
Definition
| grow best at a pH ABOVE 7 |
|
|
Term
| what is another term for alkalinophiles? |
|
Definition
|
|
Term
|
Definition
| do not need oxygen, do not want it, and will not use it. but O2 is not toxic to it. |
|
|
Term
|
Definition
usually a bacterium, that makes ATP by aerobic respiration if oxygen is present but is also capable of switching to fermentation. In contrast, obligate anaerobes die in presence of oxygen.
examples: Staphylococcus (Gram positive), Escherichia coli (Gram negative), Corynebacterium (Gram positive), and Listeria (Gram positive). Organisms in the kingdom Fungi can also be facultative anaerobic, such as yeasts. |
|
|
Term
| what are some examples of Gram (+) |
|
Definition
Staphylococcus (Gram positive), corynebacterium (Gram positive),
Listeria (Gram positive). |
|
|
Term
| what is an example of gram (-) |
|
Definition
| Echerichia coli (Gram negative) |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
| what 2 compartments does a EUK cell contain? |
|
Definition
|
|
Term
| would you have a greater chance of finding nuclear pores in a prok or euk cell? |
|
Definition
euk cell.
large protein complexes that cross the nuclear envelope, which is the double membrane surrounding the eukaryotic cell nucleus. |
|
|
Term
|
Definition
found in euk cells surrounding the cell nucleus.
it allows the transport of water-soluble molecules across the nuclear envelope.
This transport includes RNA and ribosomes moving from nucleus to the cytoplasm and proteins (such as DNA polymerase and lamins), carbohydrates, signal molecules and lipids moving into the nucleus.
It is notable that the nuclear pore complex (NPC) can actively conduct 1000 translocations per complex per second. Although smaller molecules simply diffuse through the pores, larger molecules may be recognized by specific signal sequences and then be diffused with the help of nucleoporins into or out of the nucleus. |
|
|
Term
| what are nuclear pores regulated by? |
|
Definition
| the NPC (nuclear pore complexes). |
|
|
Term
| what do nuclear pores control? |
|
Definition
entry/exit of nucleic acids, and proteins in euk cells.
they DO NOT control ions, gases, water |
|
|
Term
| what do some intracellular membranes communicate with? |
|
Definition
1. fission and fusion. (ER, golgi, endosomes, PM, lysosomes)
2. secretory pathways- proteins made in RER--> vesicle-->golgi-->vesicle-->PM |
|
|
Term
|
Definition
Lysosome ~4.5
Endosome ~5.0-6.0(late) and ~6.5-6.8(early)
Golgi ~6.5-6.7
Intermembrane space of mito ~7.0
Cytosol (+ Nucleus and ER) ~7.4
Mito Matrix ~8.0 |
|
|
Term
| the envelope surrounds the _______ |
|
Definition
|
|
Term
|
Definition
1. hetero: stains darkly due to heavy complex of protein
2. euchromitin: stains lightly due to not much protein |
|
|
Term
| what are 6 of the non membrane bound subcompartments in the nucleus? |
|
Definition
Nucleolis
inclusion bodies
cajal bodies
GEMS
storage SNURPS
modifying location
etc.... |
|
|
Term
| seperation of tsl and tcr: cotranscriptional translation occurs in ____ only. NOT _____. |
|
Definition
|
|
Term
| not ALL ____ cells have 1 nucleus |
|
Definition
EUK.
Mamalian RBC's, HIV T-cells etc.. |
|
|
Term
| in regard to the plasma membrane, what 3 things does it allow for the cell? |
|
Definition
1. an internal environment different from the extracellular matrix
2. communication b/t cells--> components in extra cellular matrix
3. some molecules to pass more readily than others! |
|
|
Term
| in the plasma membrane, which molecules are allowed to pass the fastest, slowest and med? |
|
Definition
fastest: gas and other hydroPHOBIC molecules
med: H2O- aqua porins influence
slowest: ions and sugar |
|
|
Term
| if passing WITH the gradient, an _________ is required which enables _______. |
|
Definition
ion channel protein
facilitated diffusion
those which are NOT passive are gated by voltage, temp and ligand binding |
|
|
Term
| if passing against the gradient, a ______________ is required |
|
Definition
carrier protein
most ion channels are gated and NOT passive. |
|
|
Term
| nucleus was once a cell that more than likely got _______ up. |
|
Definition
|
|
Term
| ribosomes of mitochondria resemble |
|
Definition
|
|
Term
|
Definition
DNA, dsDNA
circular: proks
linear: euks |
|
|
Term
|
Definition
DNA/RNA
and kind of Nuc Acid imaginable (ss/ds, DNA/RNA, circular/linesr etc...) |
|
|
Term
| what can proofread while replicating? |
|
Definition
|
|
Term
3'-5' exonuclease activity:
what does it do, and when does it occur? |
|
Definition
does: DNA pol's proofreading mechanism
occurs: during replication |
|
|
Term
| what acts directly after replication to catch any mistakes which have occured? |
|
Definition
|
|
Term
| what do mistakes which do not get fixed become? |
|
Definition
mutations.
occur: one millionth of an event per gene per generation |
|
|
Term
|
Definition
|
|
Term
| define the anatomy of the mitochondria |
|
Definition
2 lipid bilayers
mito matrix
intermembrane space; contain DNA |
|
|
Term
| where does glycolysis occur? |
|
Definition
| occurs in both aerobic and anaerobic in the cytoplasm outside the mitochondria |
|
|
Term
|
Definition
converts some of the energy in glucose to ATP and to NADH.
1st gets energy, not much ATP
always occurs in the cytoplasm |
|
|
Term
| what is another term for the creb cycle? |
|
Definition
citric acid cycle
TCA cycle |
|
|
Term
| where does the creb cycle occur in proks and where does it occur in euks? |
|
Definition
PROKS: in the cytoplasm
EUKS: in the mito matrix. it converts some of the energy from glucose to ATP, NADH,FADH2 |
|
|
Term
| where would be the better chance of finding the creb cycle of proks? |
|
Definition
|
|
Term
| where would be the better chance of finding the creb cycle of euks? |
|
Definition
|
|
Term
| where do ETS and ATP synthesis occurin proks and where does it occur in euks? |
|
Definition
across the membrane
PROKS: plasma membrane
EUKS: inner mitochondrial membrane |
|
|
Term
|
Definition
| converts NADH and FADH2 energy to an H-ion gradient form of energy (like pumping H2O up a waterfall), which ATP synthase then converts to APT energy |
|
|
Term
|
Definition
electon transfer system
it accepts energy from carriers in the matrix and stores it to a form that can be used to phosphorylate ADP. Two energy carriers are known to donate energy to the ETS, namely nicotine adenine dinucleotide (NAD) and flavin adenine dinucleotide (FAD). Reduced NAD carries energy to complex I (NADH-Coenzyme Q Reductase) of the electron transport chain. FAD is a bound part of the succinate dehydrogenase complex (complex II).
It is reduced when the substrate succinate binds the complex. |
|
|
Term
|
Definition
bounded by 2 p.-lipid bilayers
stroma
intermembrane space
thylakoid membranes and spaces inside; contain DNA |
|
|
Term
| what do plastids perform? |
|
Definition
biosynthetic reactions such as:
nitrogenous base and aa synthesis |
|
|
Term
| where are plastids found? and what is their function? |
|
Definition
location: plants and algea
function:photosynthesis
Undifferentiated plastids (proplastids) may develop into any of the following plastids:
Chloroplasts: for photosynthesis; see also etioplasts, the predecessors of chloroplasts
Chromoplasts: for pigment synthesis and storage
Leucoplasts: for monoterpene synthesis; leucoplasts sometimes differentiate into more specialized plastids:
Amyloplasts: for starch storage
Statoliths: for detecting gravity
Elaioplasts: for storing fat
Proteinoplasts: for storing and modifying protein |
|
|
Term
|
Definition
differentiated to synthesize and store starch
i.e. corn, seeds, potato roots etc. |
|
|
Term
|
Definition
| are differentiated with chlorophyll and have enzymes, etc. for photosynthesis |
|
|
Term
|
Definition
| differentiated to contain many various pigments |
|
|
Term
| each differentiated organelle requires a unique collection of _______ in order to function properly |
|
Definition
| proteins (and other molecules) |
|
|
Term
| where were most proteins in an organelle synthesized? in addition, where and by what means must they be redirected? |
|
Definition
synthesized in: the cytosol
to: final location
via: signal sequence
a sorting signal is needed to transport it, and must usually traverse a membrane at least once. sometimes more than once! |
|
|
Term
|
Definition
| A discrete sequence of amino acids in a protein that serves to identify it to transport mechanisms within a cell so as to guide the protein to its destination. |
|
|
Term
| in the nucleus.. proteins are directed there via a _____________. and go through the _________________. |
|
Definition
|
|
Term
| proteins that go in the NPC get ___________ and go enter in their ___________ form. |
|
Definition
|
|
Term
for the mito, and chloro, sequences target priteins to the organelle, and are transported through a __________.
must they get folded or unfolded before transport? |
|
Definition
channel
must get unfolded. then folded again when they return. |
|
|
Term
| for the ER, golgi, endosomes, and plasma membrane... a _________ protein just being synthesized on a ribo has its _________ halted until it goes to ____, there _____ resumes while ______ ensues as a protein emerges. |
|
Definition
nascent
tsl
RER
tsl
translocation |
|
|
Term
|
Definition
unfolded:
mito/chloro: post tsl
ER: co transcriptional
folded:
all post tsl
nuc: through NPC
peroxisome: |
|
|
Term
|
Definition
| ER is the only place that does cotranslational tralslocation |
|
|
Term
| where does the protein go from the ER? |
|
Definition
| ER-->golgi etc. via budding/fussion vesicles |
|
|
Term
| protein trafficking moves proteins through the ER and golgi by what type of mment? |
|
Definition
| movement is via coated vesicles |
|
|
Term
| what are two options for proteins outside the cell to be? |
|
Definition
constitutive-does all the time
induced-does on command |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
| similar movement which occurs during exocytosis works in _______ during _______. |
|
Definition
|
|
Term
| anterograde (w in the cell) |
|
Definition
| forward transport (ER-->golgi-->PM) |
|
|
Term
| reterograde (w in the cell) |
|
Definition
|
|
Term
|
Definition
assist in folding and unfolding proteins
unfolding is in preperation for translocation across mito or chloro |
|
|
Term
| where are chaperones found, and what energy do they use to carry out their task? |
|
Definition
location: most compartments in cells
energy used: ATP |
|
|
Term
| @ which 3 points do proteins get folded or unfolded by chaparones? |
|
Definition
1. when they are 1st made.
2. after they enter the compartment
3. after heat (or other) stress to a cell
the chaparone is NOT modified in the process |
|
|
Term
| what do exposed hydorPHOBic patches signal? |
|
Definition
| that a protein needs help folding itself |
|
|
Term
| what is the shape of a euk cell determined by? |
|
Definition
| the shape of its cytoskeleton |
|
|
Term
| when do most cytoskeletal fibers rearrange themselves in meiosis and mitosis? |
|
Definition
at the beginning of mitosis,
during prophase (and then again in telophase) of meiosis |
|
|
Term
| what are the largest cytoskeletal fibers? and what are they made of? |
|
Definition
microtubules
made of tubulin
2 dif types of tubulin: alpha and beta |
|
|
Term
| what are 2 dif types of tubulin? and what does tubulin make? |
|
Definition
alpha + beta
makes microtubules |
|
|
Term
|
Definition
| is a cellular "scaffolding" or "skeleton" contained within the cytoplasm. The cytoskeleton is present in all cells; it was once thought this structure was unique to eukaryotes, but recent research has identified the prokaryotic cytoskeleton. It is a dynamic structure that maintains cell shape, protects the cell, enables cellular motion (using structures such as flagella, cilia and lamellipodia), and plays important roles in both intracellular transport (the movement of vesicles and organelles, for example) and cellular division |
|
|
Term
|
Definition
| introduceed the cytoskeleton in 1931 |
|
|
Term
|
Definition
part of the cytoskeleton.
medium size
Like actin filaments, they function in the maintenance of cell-shape by bearing tension
(microtubules, by contrast, resist compression. It may be useful to think of micro- and intermediate filaments as cables, and of microtubules as cellular support beams).
They also participate in some cell-cell and cell-matrix junctions. |
|
|
Term
|
Definition
| smallest- also called microfilaments- made of actin dimers |
|
|
Term
| location in cell structure... |
|
Definition
barr bodies next to nuclear envelope- (nuc skeleton tells barr body to go there)
rRNA genes
golgi bodies adjacent to the RER
centrioles templating perpendicularly on existing centrioles
dorsal ventral gradients of proteins INSIDE the cytoplasm |
|
|
Term
| what executes predefined responses in the cell? |
|
Definition
| signal transduction pathways |
|
|
Term
|
Definition
| transduce a signal from outside the cell to an effector region inside the cell (often regulation gene expression in the nuc) |
|
|
Term
| where is a place gene expression occurs? |
|
Definition
|
|
Term
| to illustate a signal transduction pathway, you would need a... |
|
Definition
| to begin w a ligand binging to a cell-surface receptor |
|
|
Term
| translocation- folded and unfolded |
|
Definition
folded- all post tsl, nuc through NPC, peroxisome
unfolded- post tsl in mito and chloro, co-tsl in ER |
|
|
Term
| do all organisms have cells that can grow and divide? |
|
Definition
|
|
Term
| how do BAC and ARC grow and divide? |
|
Definition
bionary fussion (split into two)
No stages of mitosis |
|
|
Term
| how do yeast and other fungi grow and divide? |
|
Definition
| budding. (vesicle coming off ER or golgi) |
|
|
Term
| division and growth of mitosis and meiosis cells? |
|
Definition
|
|
Term
| what is the purpose of differentiation? |
|
Definition
| to produce specialized cell types, inc terminally differetiated cells |
|
|
Term
| differetiation in somatic cells |
|
Definition
| somatic cells are specialized for a specific function in the organism, are DIPLOID vs germ cells (sperm and oocytes) which are HAPLOID |
|
|
Term
|
Definition
the ability to form any cell
i.e. a fertilized zygote |
|
|
Term
|
Definition
| multipotent or pleuripotent- meaning they have more potential functions or "having more than one potential outcome." |
|
|
Term
| do terminally differetiated cells have the capacity to divide? |
|
Definition
| no they lost their capacity to divide |
|
|
Term
| what 5 things do membranes enable cells to do? |
|
Definition
1. maintain homeostasis
2. control solute concentrations across membranes
3. process info
4. transport nutrients in and waste out
5. adapt to altered metabolic situations |
|
|
Term
| other than the nuc envelope, membranes require proteins to transport what? |
|
Definition
| ions, and small polar molecules |
|
|
Term
| what maintains ion concentration differences? |
|
Definition
membrane proteins.
they create electron gradients |
|
|
Term
| in the electron gradients from membrane proteins, what 3 things are highest outside the cytosol? |
|
Definition
|
|
Term
| in the electron gradients from membrane proteins, what is highest inside the cytosol? |
|
Definition
|
|
Term
| inside of a resting animal cell is slightly __________ due to membrane proteins |
|
Definition
|
|
Term
| channel proteins contain a |
|
Definition
| pore region through which solutes are able to pass at HIGH flux (widespread) rates when the channel is OPEN |
|
|
Term
| solutes can pass through the pore region at low or high rates when the channel is open or closed? |
|
Definition
| can pass at HIGH rates when the channel is OPEN |
|
|
Term
| pore regions are: _______ to ________ concentration when guards are ______. |
|
Definition
high --> low
when guards are open |
|
|
Term
| what 3 things do channel proteins have? |
|
Definition
SRG
1. solute selectivity
2. rapid rate of solute permeation
3. gating mechanism |
|
|
Term
| what are 5 examples of ion channels? |
|
Definition
1. aquaporins --> H2O
2. porins (in proks, mit) porin like protein (mito outer membrane)
3. gap junctions b/t synaptic regions- nerve-->nerve
4. NPC's in nuc envelope
5. ER protein translocaters for nascent polypeptides during the process of tsl |
|
|
Term
|
Definition
| coming or having recently come into existence |
|
|
Term
| most ion channel proteins are selective for a particular solute, however, some are general |
|
Definition
cationic or anionic.
normally cannot do both. |
|
|
Term
| what are channel proteins regulated by? and what changes do they undergo? |
|
Definition
regulated by gating
they undergo conformational changes to open and close in response to a specific stimuli |
|
|
Term
| what are 5 types of channel gating? |
|
Definition
1. ligand gated (something to which, usually a protein, will be binding to the channel)
2. voltage gating
3. stretch-activated
4. temperature-activated
5. pressure-activated |
|
|
Term
| what gradient dictates the direction of the movement in channels |
|
Definition
| the electro-chemical gradient (ECG) |
|
|
Term
| in ECG, are the speeds fast or slow? |
|
Definition
| the speed is very fast! up to 10^8/s which is also close to the max rate of diffusion of ions in H2O. |
|
|
Term
| what do carrier proteins bind solutes to? |
|
Definition
| one side of the membrane. they also undergo ALLOSTERIC change, and release them on the other side of the membrane, but are NOT as fast as a channel!!! |
|
|
Term
| which are faster? channel proteins or carrier proteins? |
|
Definition
|
|
Term
|
Definition
| of, relating to, undergoing, or being a change in the shape and activity of a protein (as an enzyme) that results from combination with another substance at a point other than the chemically active site |
|
|
Term
| carrier proteins transduce their energy from which 3 things? |
|
Definition
AEO
ATP
Electrochemical gradients
other energy sources
into transport of substrates AGAINST A CONCENTRATION GRADIENT (active transport!!!) |
|
|
Term
| are transporters and pumps a part of carrier or channel proteins? |
|
Definition
|
|
Term
| what are 2 main types of carrier proteins? |
|
Definition
|
|
Term
| what are 3 types of transporters and where do they get their energy from? |
|
Definition
1. unitransporters
2. symporters (cotransporter)--> both molec's are moving in same direction across the membrane
3. anti-porter: (exchangers) moving in opposite directions
they get their energy from electochemical gradients to facilitate movement of substrates across the membrane |
|
|
Term
| where do pumps get their energy from and what do they use it for? |
|
Definition
| ATP. they use it directly to drive energetically less favorable substrate accumulation or efflux |
|
|
Term
| what are 2 catagories of active transport and what are they a part of? |
|
Definition
| primary and secondary active transports. they are a part of carrier proteins! |
|
|
Term
| primary transports use what as their energy source and what does it do? |
|
Definition
| ATP. and this transports solutes AGAINST the gradient! |
|
|
Term
| what are some examples of primary transports? |
|
Definition
Ca2+ -ATPase
Na+/K+ -ATPase
they work to maintain gradients of solutes across membranes
and are a part of the carrier proteins |
|
|
Term
| do primary or secondary active transports (pumps) use ATP directly? |
|
Definition
| primary does. secondary DOES NOT!! |
|
|
Term
| secondary transport pumps-carrier proteins |
|
Definition
do not use ATP directly.
use energy stored in electochemical gradient to drive trans-membrane solute transport |
|
|
Term
| hydration of ions influences their flux through what? |
|
Definition
|
|
Term
| ions in hydration are what? |
|
Definition
hydrated...
need to know how to draw hydrated ions |
|
|
Term
| a hydration shell is formed around each ion, its formation is |
|
Definition
|
|
Term
| what does the size of the hydration shell depend on? |
|
Definition
| the size of the ion and charge density |
|
|
Term
| what enables part of the the dehydration of ions as they travel through? |
|
Definition
ion channels.
as the ions travel through, it forms weak bonds with aa residues, these help to make the transport process energetically favorable and selective. |
|
|
Term
| what needs to bond in order to help to make the transport process energetically favorable and selective |
|
Definition
| aa residues and ions. they make weak bonds |
|
|
Term
| what is critical to hydration of ions? |
|
Definition
| specific channel and ion binding sites are important |
|
|
Term
| electrochemical gradients occur where? |
|
Definition
|
|
Term
| what is the charge difference across the plasma membrane characterized by? |
|
Definition
| the inside being (-) charged relative to the outside |
|
|
Term
| what is the electrochemical gradient composed of and what is it maintained by? |
|
Definition
| the charge dif. and the concentration dif. across a membrane. it is maintained by channels and carrier proteins. |
|
|
Term
| when does a membrane potential exist? |
|
Definition
when there is an electrochemical gradient, which requires 2 things...
1. the ion concentration dif across the membrane resulting in a charge separation.
2. membrane which is SELECTIVELY PERMEABLE for at least one of the ionic species |
|
|
Term
| what are the major contributors to membrane potential in animal cells? |
|
Definition
|
|
Term
| what are the minor contributors to membrane potential in animal cells? |
|
Definition
|
|
Term
| is there more K+ on the inside or the outside? |
|
Definition
|
|
Term
| what kind of channels open at the resting potential allowing K+ ions out of the cell, and down the ECG? |
|
Definition
|
|
Term
| what what Na+/K+ -ATPase do? |
|
Definition
helps to:
1. make the INSIDE more NEGATIVE
2. maintain K+ gradient so the leak channels keep working |
|
|
Term
| what keeps the K+ leak channels working? |
|
Definition
| the maintaining of the K+ gradient |
|
|
Term
| how many K+'s and Na+'s are pumped in a cell? and which is pumped in and which is pumped out? |
|
Definition
2K+ INTO cell
3Na+ out of cell
in the K+/Na+ -ATPase |
|
|
Term
|
Definition
carrier protein
primary pump
uses ATP |
|
|
Term
| membrane potential changes according to what? |
|
Definition
| which ions have the MOST OPEN channels at a time |
|
|
Term
|
Definition
occurs when Na+ or Ca2+ channels OPEN, and the ions flow INTO the cell.
this makes the membrane potential more positive! |
|
|
Term
|
Definition
occurs when K+ channels OPEN, and K+ moves OUT of the cell.
this makes membrane potential more NEGATIVE |
|
|
Term
| what do K+ channels catalyze? |
|
Definition
| selective and rapid ion permeation |
|
|
Term
| K+ channels form a narrow ___________, and are _____ selective for K+ over other cations. |
|
Definition
|
|
Term
|
Definition
tetromeres
each additional subunit contributes to a centra pore |
|
|
Term
| what are the 2 main parts of the K+ channel? |
|
Definition
1. central cavity
2. selectivity filter |
|
|
Term
| what does the central cavity a part of, and what does it do? |
|
Definition
part of: the K+ channel
function: helps to stabilize K+ ions BEFORE they go through |
|
|
Term
| what does the selective filter do, and what is it part of? |
|
Definition
part of: K+ channel
function: partly dehydrates the ions in order for them to pass through. this is possible due to the (-) charge of the O2 atoms in the selectivity filter which act as surrogate water molecules and thus LOWER the dehydration energy for the permeating K+ ions. |
|
|
Term
| why are Na+ ions not likely to go through the K+ channel? |
|
Definition
| bc they have the wrong size hydration shell to fit through in a way to allow dehydration to be energetically favorable to the cell. |
|
|
Term
| what are voltage dependent Na+ channels activated by? |
|
Definition
membrane depolarization
translate electrical signals |
|
|
Term
| what do voltage dependent Na+ channels require? |
|
Definition
| electrochemical Na+ grad. generated by the Na+/K+ -ATPase |
|
|
Term
| where are IMP's formed, and what are they for? |
|
Definition
| they are formed in the voltage dependent Na+ channels and are important bc they transport Na+ ions down their electrochemical gradient |
|
|
Term
| what is easily removed? IMP or PMP? |
|
Definition
|
|
Term
| what includes all transmembranes + others? IMP or PMP? |
|
Definition
|
|
Term
| what happens within depolarization? |
|
Definition
| Na+ channels open, it flows in the cell and down the gradient, and within milliseconds the channel closes. Na+ influx then ceases. |
|
|
Term
| LAB QUESTION: what part of these Na+ channels also binds to tetrodotoxin from puffer fish, and causes paralysis by inactivating the voltage gated Na+ channels involved in initiation and propagation of action potentials in nerve cells? |
|
Definition
| the selectivity filter of Na+ channels |
|
|
Term
| what is a target for local anesthetics? |
|
Definition
| Na+ channels. bc they bind to the INTRACELLULAR side of the Na+ channel and inhibit membrane depolarization |
|
|
Term
| what is an ENaC, and what does it do? |
|
Definition
epithelial Na+ channel
1. regulated by hormones which are not rapidly inactivated
2. partially voltage dependent
3. 1st found in epithelial cells
4. are found in many other cells but still called ENaC's
5. mediate bulk flow of Na+ ions, influence water transport across cell layers
6. function depends on the Na+ gradient established by the Na+/K+ -ATPase |
|
|
Term
| where are ENaC's located? |
|
Definition
| in the apical membrane of epithelial cells in the distal tube and collecting ducts of each kidney neuron. |
|
|
Term
|
Definition
| they allow Na+ ions from the filtrate to enter the cells down their gradient. the Na+/K+ ATP-ase help by removing Na+ out of the cells and transporting it back to the capillary. |
|
|
Term
| what 2 things is the reabsorption of Na+ regulated by? |
|
Definition
aldosterone from the adrenal glands
vasopressin from the pituitary gland which bind to the receptors on kidney cells |
|
|
Term
| which drug blocks Na+ reabsorption by ENaC in the luminal membrane of the kidney dorsal tubule and collecting duct? |
|
Definition
| the diuretie drug amiloride |
|
|
Term
| what does decreased Na+ reabsorption do? |
|
Definition
| lowers Na+ concentration in the blood and lowered or normalized blood pressure |
|
|
Term
| what activates intracellular functions? |
|
Definition
| plama membrane Ca2+ channels |
|
|
Term
| Ca2+ concentrations are _________ in the extracellular fluid and in the ____ and ____. |
|
Definition
higher
ER
SR
they are 10^4 times lower in the cytoplasm for resting cells |
|
|
Term
| what catalyzes the selective transport of Ca2+ ions down their ECG into the cytosol? |
|
Definition
| Ca2+ channels in the ER SR or PM |
|
|
Term
| what are Ca2+ channels gated by? |
|
Definition
| extra or intracellular ligand, voltage charges or Ca2+ itself! |
|
|
Term
| what impact does Ca2+ have on the intracellular Ca2+ |
|
Definition
it increases it.
also triggers:
1. muscle contraction
2. Hormone or neurotransmitter release
3. activation of Ca2+ dependent signaling cascades
4. gene transcriptions |
|
|
Term
| why are Ca2+ channels highly sensitive? |
|
Definition
| bc of selectivity filters\\they have a permeation factor rate of 10^6/s |
|
|
Term
| in invitro assays, what functions as a non-selection anion channel? |
|
Definition
| Cl- channels. they can conduct other anions. |
|
|
Term
| in vivo, ______ is the most abundant _____. |
|
Definition
|
|
Term
| what is the predominant ion transported by these channels in vivo? |
|
Definition
|
|
Term
| what 2 things are intrinsically coupled in Cl- channeling? |
|
Definition
ion conductance
gating
they have (+) regions pointing into the center plane of the membrane |
|
|
Term
| 3 diff gene families in Cl- channeling |
|
Definition
1. CLC gene family
2. cystic fibrosis transmembrane conductance regulator
3. ligand-gated (amniobutyric acid GASA) receptor and glycerine receptor family |
|
|
Term
| what 6 things are aquaporins involved in? |
|
Definition
1. concentration of urine by the kidneys
2. digestion
3. regulation of body temp
4. secretion and absorption of spinal fluid
5. secretion of tears/saliva, sweat, bile,
6. reproduction |
|
|
Term
|
Definition
aquaporins.
each subunit from a pore |
|
|
Term
| which 3 feature confer water-specificities of an aquaporin? |
|
Definition
SEW
1. size restriction--via a constriction region
2. electrostatic repulsion--via (+) R groups lining the pore
3. water dipole orientation |
|
|
Term
| in kidneys, what does aquaporin 1 do? |
|
Definition
| it helps to concentrate 18L of blood filtrate per day into a urine volume of ~1.5L per day by reabsorbing |
|
|
Term
| aquaporin 1 has high water permeability in the epithelial cells of the proximal convoluted tubules and decending thin limbs of the _____________. |
|
Definition
|
|
Term
| what does vasopressin do? |
|
Definition
| stimulates expression of aquaporin 2 in the collecting ducts, resulting in increased urine concentration! |
|
|
Term
| what are action potentials? |
|
Definition
| electrical signals that depend on several types of ion channels |
|
|
Term
| what does action potential begin w? |
|
Definition
| the opening of the voltage gated Na+ channels, rapid flow of Na+ ions into the cell-->membrane depolarization |
|
|
Term
| in action potentials, what do K+ currents do? |
|
Definition
they balance the Ca2+ channels.
more K+ exit the cell-->repolarization
Na+/K+ ATP-ase is at work the entire time, and now drives the membrane toward repolarization to reestablish the resting (-) potential. |
|
|
Term
| what are cardiac and skeletal muscles activated by? |
|
Definition
| excitation contraction coupling |
|
|
Term
| are Ca2+ primary or secondary messengers? |
|
Definition
|
|
Term
| what signal regulates heart rhythm and muscle contraction? |
|
Definition
| Ca2+ signaling regulates these |
|
|
Term
| Ca2+ is lower in what cells? |
|
Definition
| resting. as opposed to the ECM or ER concentrations |
|
|
Term
| voltage dependent Ca2+ channel cells sense the change and open allowing for a small flux in Ca2+ to enter the cytosol |
|
Definition
| in excitation-contraction coupling when depolarization occurs from an incoming action potential |
|
|
Term
| what stimulates lots of release of Ca2+ from the Er through RyR's? |
|
Definition
| voltage dependent Ca2+ channel cells sense the change and open allowing for a small flux in Ca2+ to enter the cytosol |
|
|
Term
|
Definition
Ca2+, Ca2+ channels
also bind to a plant alkaloid ryanodine w/ high specificity, BLOCKING the channel!!! |
|
|
Term
| what activates a Ca2+ sensitive protein troponinc? and what does it do? |
|
Definition
huge increase in cytosolic Ca2+
it stimulates the concentration of myofilaments |
|
|
Term
| what causes a muscle to relax? |
|
Definition
| extrusion of Ca2+. you must get the Ca2+ out of the muscle. |
|
|
Term
| how does extrusion of Ca2+ from a muscle occur? |
|
Definition
1. re-uptake of Ca2+ ions into the SR by the SR, Ca2+ ATPase (pump)
2. removal of Ca2+ ions from the cytosol by the Na+/Ca2+ exchanger in the PM |
|
|
Term
| **********what is another type of Ca2+ release channel?******* |
|
Definition
| IP3 receptor, or inositol 1,4,5-triphosphate |
|
|
Term
| what are 2 families of glucose transporter proteins? |
|
Definition
1 .GLUTS-uniporters whichi mediate facilitated transport of glucose DOWN concentration gradient
2. Na+/glucose:cotransporters couple energy from the transmembrane Na+ gradient to the transport of glucose |
|
|
Term
| what superfamily are GLUTS a part of? |
|
Definition
MES
largest family of proteins involved in the membrane transport |
|
|
Term
| what 2 things can GLUTS do? |
|
Definition
1. carry glucose, galactose, water, painkillers
2. mediate transport of soplutes in or out of cells, depending on solute concentration
3. |
|
|
Term
|
Definition
| important to facilitate glucose into the brain by transporting glucose from the blood into the epithelial cell into the ECM and them into an astrocyte |
|
|
Term
|
Definition
insulin responsive transporter,
undergoes regulated induced by transport of insulin to the cell surface.
it mediates glucose uptake by muscle and adipose tissues |
|
|
Term
| the GLUT 4 proteins are located where? |
|
Definition
| in intracellular vesicles that upon cell signals fuse with the PM resulting in delivering the GLUT 4 transporters to the PM |
|
|
Term
| what causes TYPE II diabetes? |
|
Definition
| not enough GLUT 4 in the plasma membrane |
|
|
Term
| which way to symporters and antiporters move across the concentration gradient? |
|
Definition
| they move AGAINST its transmembrane ny using the energy of the other solute moving DOWN |
|
|
Term
| many transporters are a part of the MFS |
|
Definition
|
|
Term
|
Definition
bacterial lactose permease, a monomeric ogliosaccharide/H+ symporter
it uses the H+ gradient (towards cytosol) to drive accumulation of nutrients AGAINST its concentration gradient |
|
|
Term
| LacY can go which direction? |
|
Definition
| in the other direction and use a lactose gradient to generate a H+ gradient |
|
|
Term
| what is a H+ gradient of a LacY generated by? |
|
Definition
| ETS and ATP synthase (f0/F1 ATPase) which couples ATP hydrolosis to the export of protons from the cytosol |
|
|
Term
|
Definition
| out to going in. with lactose coming in. |
|
|
Term
| what are 4 transporters which utilize the Na+ gradient? |
|
Definition
1. voltage dependent Na+ channels
2. epithelial Na+ channels (ENaC)
3. Na+/substrate transporters
4. Na+ dependent transporters involved in pH rehulation |
|
|
Term
| what 5 things do Na+/substrates transport? |
|
Definition
1. ions
2. sugars
3. aa's
4. vitamins
5. urea |
|
|
Term
| the Na+/Ca2+ exchanger transports |
|
Definition
| 3 Na+ in exchange for 1 Ca2+. this generates a net electrogenetic current of +1 per cycle |
|
|
Term
| what cotransporter mediates eletroneutral transport with a stoichiometry of 1:1:2? |
|
Definition
the Na+/K+ ATPase. these are transported INTO cells and are important to:
1. maintain intracellular Cl- concentration
2. reabsorption of NaCl from the kidney filtrate |
|
|
Term
| Na+/Mg+ exchanger transports what? |
|
Definition
2Na+ for each 2Mg+ extruded
thus transport is electroneutral under psyiological conditions
it is imp to rid the excess Mg2+ that permeates into the cytosol at a very slow rate |
|
|
Term
| the Na+/H+ exchanger and the Na+/HCO3- both use what? |
|
Definition
| the energy of the transmembrane Na+ gradient to regulate pH |
|
|
Term
| how do the lungs and the kidney assist in maintaining the acid-base balance of the plasma? |
|
Definition
| by excreting CO2 OUT OF THE LUNGS and H+ INTO THE URINE |
|
|
Term
| the secretion of H+ into the luminal filtrate (urine) does what? |
|
Definition
| the apical membrane Na+/H+ exchanger |
|
|
Term
| (NHE)is coupled to the transport of an equal # of |
|
Definition
| HCO3- INTO blood via the Na+/HCO3- cotransporter in the basolateral membrane of the epithelial cells of the prok tubule |
|
|
Term
| what functions as a intracellular Ca2+ storage compartment? |
|
Definition
|
|
Term
| after what signaling has occurred does the resting Ca2+ concentration reestablish? |
|
Definition
|
|
Term
| what is the main type of Ca2+ transport protein to extrude from the cytosol? |
|
Definition
| Ca2+ ATPase in the ER and in the PM |
|
|
Term
|
Definition
| sarcaplasmic recticuleum Ca2+ ATPase |
|
|
Term
| what does SERCA do in muscles? |
|
Definition
| it gets most of the Ca2+ out |
|
|
Term
| the SERCA pump reaction cycle consists of what? |
|
Definition
| a sequence of phosphorylation and dephos. events that power the uphill transport of Ca2+ into the SR per hydrolyzed ATP in exchange for 2 H+ ions |
|
|
Term
| what does the PMCA pump do? |
|
Definition
| the pump functions similarly to the SERCAs except that they transport 1 Ca2+ per ATP instead of 2 Ca2+'s.. also there are not as many of them |
|
|
Term
| how are PMCA pumps and SERCA pumps different? |
|
Definition
1. SERCA pumps 2Ca2+ for every ATP
2. PMCA pumps 1Ca2+ for every ATP |
|
|
Term
| how are SERCA and PMCA the same? |
|
Definition
1. both P-type pumps
2. ATP dependent
3. use ATP to autophosphoylate a conserved aspartic acid residue |
|
|
Term
| what maintains the OM Na+ and K+ gradients? |
|
Definition
|
|
Term
| what are the 2 MAJOR components of the ECG across the euk PM? |
|
Definition
|
|
Term
| what is it that reg.'s the osmotic pressure and allows for 2ndary Na+ dependent transport of molecules? |
|
Definition
| it is the (-) resting membrane potential |
|
|
Term
| the electro chemical gradient is generated and maintained by the ______________, which belongs to the family of ___________ ATPases, which means that it ________________ an aspartic acid residue as an intermediate during ion transport. the terminal phosphate is transferred from ____ to the active site on the enzyme. |
|
Definition
Na+/K+ ATPase
P-type
autophosphorylates
ATP |
|
|
Term
| for each ATP hydrolyzed, __ Na+ are moved ___ and ___ K+ are moved from the ___ into the cytosol. this cycle operates ~____/s |
|
Definition
|
|
Term
| an _____ potential difference and an _____ ion gradient across the PM are created as 3 Na+ are moved out and 2 K+ are moved from the ECF--> cytosol |
|
Definition
|
|
Term
| which pump is reversible and is targeted by drugs and toxins? |
|
Definition
|
|
Term
| plant steriods called ____________, eg __________, __________ -specifically inhibit ion transport by which pump? |
|
Definition
cardiac glycosides
oubain
digitalis
it is the Na+/K+ ATPase pump! |
|
|
Term
| what is from the foxglove plant, and what can it be used to treat? |
|
Definition
digitalis.
can be used to treat heart failure bc a small amt will increase cytoplasmic [Na+] which results in higher cytoplasmic [Ca2+] which increases the contractility of the heart. |
|
|
Term
| what synthase couples H+ mment to ATP synthesis or hydrolysis? |
|
Definition
|
|
Term
| in F1/Fo-ATP synthase, the molecular motor couples energy of the electrochemical _________ across the ___ of ____ cells, or the ______ of EUK cells. |
|
Definition
H+ gradient
PM of PROK cells
inner membrane of EUK cells |
|
|
Term
structure of the F1/Fo-ATP synthase:
the ____ domain is the Fo region, is involved in translocation of protons down their ECG, the _____ (prok) or _____(euk) globular domain in the F1 region, contains catalytic sites responsible for ATP synthase |
|
Definition
transmembrane
cyto
mito matrix |
|
|
Term
| in the F1/Fo-ATP synthase, how many protons are transported for ATP synthesized? |
|
Definition
|
|
Term
| the F1/Fo-ATP synthase pump can work |
|
Definition
|
|
Term
| how does the F1/Fo-ATP synthase pump work in reverse? |
|
Definition
| some bacterial cells use ATP hydrolysis to generate H+ gradient which other membrane proteins can use to move solutes |
|
|
Term
| what transports protons out of the cytosol? |
|
Definition
|
|
Term
| in the ________ pump, ______ proton [umps (V-ATPases) are H+/ATPases essential for maintaining the pH of organelles such as ________, endosomes, which need a more acidic environment that the cytosol. |
|
Definition
H+ -ATPases
vacuolar
lysosomes |
|
|
Term
| H+ -ATPases have 2 functional domains. what are they and what do they do? |
|
Definition
V1 and Vo.
V1- which binds and hydrolyses ATP which provides the energy for proton translocation across the membrane bound Vo domain. |
|
|
Term
|
Definition
|
|
Term
| What is the smallest cell? |
|
Definition
|
|
Term
| what is the largest cell? |
|
Definition
|
|
Term
| what are 4 minimal features of a cell? |
|
Definition
PIGE
Plasma membrane, genome, information transfer, energy utilization |
|
|
Term
| what is the lipid bilayer impermeable to? |
|
Definition
| ions, small charged molecules, and all large molecules |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
| segregates the cell from its environment |
|
|
Term
| which cells have a lipid bilayer? |
|
Definition
|
|
Term
| Some proteins that are located in the plasma membrane are called what? |
|
Definition
|
|
Term
| Why are the proteins and lipids called glycoproteins and glycolipids? |
|
Definition
| bc of the sugar on the proteins makes a coat around the cell |
|
|
Term
| What kind of linkage is there between the phospholipids heads and tails? |
|
Definition
|
|
Term
What is the area contained by the plasma
membrane called? |
|
Definition
|
|
Term
| what is the simplest form of bacteria? |
|
Definition
|
|
Term
| what does a gram (+) cheek cell look like? |
|
Definition
| It will stain a darker purple because of the Thicker cell wall the cell wall surrounds the plasma membrane |
|
|
Term
| what does a gram (-) cheek cell look like? |
|
Definition
| It will stain pink because the color gets washed Out due to the thinner cell wall it has a plasma membrane and thin cell wall and another membrane around that |
|
|
Term
| what is the region between the outer and inner membrane called? |
|
Definition
|
|
