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cell bio II
cell bio 401 exam II
195
Biology
Undergraduate 3
03/22/2009

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Term
cell size
Definition
10-20 micrometers
Term
resolution
Definition
wavelength and apature determines it
Term
wavelength
Definition
inversely related to resolution
Term
resolution limit of light microscpope
Definition
200nm
Term
Light can be
Definition
reflected, emmitted, absorbed, refracted
Term
absorption method
Definition
staining, can stain black or individual organelles
Term
antibody linked enzymes
Definition
create colored stains for light microscopy
Term
refraction/phase contrast
Definition
good for seein living cells, use phase anulus and phase ring
Term
fluoresence microscopy
Definition
absorbin light and reflecting longer wavelength, called "stokes shift"
Term
excitation filter
Definition
lets in only blue light for fluorescent microscopy 450-490nm
Term
dichoric beam splitter
Definition
reflects 450-490 and transmits light above 510nm
Term
emission filter
Definition
allows only 520-560nm to get through
Term
confocal microscopy
Definition
improves fluorescent microscopy by detecting only light from focus object
Term
Total internal reflection fluorescence microscopy (Tirf)
Definition
allows visualization of molecules close to surface
Term
Electron Stains
Definition
absorb electrons, are metal, can give 3d images, gold silver or tungsten.
Term
Scanning electron microscopy
Definition
electrons bounced toward detector light spot and electrons bounced away produce dark spot
Term
Endosymbiosis
Definition
one organism resides in another, established in mitochondria by Lynn Margulis
Term
Endosymbiosis support
Definition
own genome, double membrane, and divide by fission process
Term
Mitochondria # variance
Definition
depends on energy use in cell, sperm have no mitochondria info, mother donates mitochondria, used to track metabolic diseases
Term
Porin
Definition
decorate mitochondrial outermembrane and allow water molecules and small ions through
Term
inner mitochondrial membrane
Definition
have folds called christae and surrounds mitochondrial matrix space
Term
cristae
Definition
most abundant in high energy cells, contains cardiolipin, and the components of the electron transport chain and ATP synthase.
Term
Matrix space
Definition
contains citric acid cycle that produces NADH
Term
4 steps of electron trasnport
Definition
1.)NADH is oxidize by NADH hydrogenase freeing two eletrons
2.)Electrones go to diffusable ubiquinone which goes to cytochrome bc1 complex
3.)Cytochrome c diffusable takes it to cytochrome oxidase complex
4.)electrons removed from cytochrome oxidase by oxygen to form water
Term
at each complex a proton is
Definition
is recruited from matrix and then released in the intermembrane which creates .2volt potential
Term
Short circuits by .2volt potential
Definition
are prevented by protein insulators and metal ions and heme groups which mediate electron transport
Term
superoxide radicals
Definition
generated in electron transport can be sequestered by cytochrome oxidase. can cause damage and aging
Term
ATP synthase
Definition
converts proton motive force into energy. composed of F0 head and F1 head connected by protein arm.
Term
F0 stalk region
Definition
spins with electron flow and attaches to head. similar to spinning of flagella
Term
F1 head
Definition
3 binding sites, ADP + P, ATP, empty,
Term
Plastids
Definition
proplastids, amyloplast for storage, chromoplasts, for color, and chlorplast
Term
chloroplast
Definition
double bound membrane plus thylakoid
Term
thylakoid membrane
Definition
enlcoses thylakoid space, houses electron transport chain, ATP synthase, and photosynthetic material.
Term
chloroplast create NADH and ATP with
Definition
using electrons donated from water, light energy (light reaction) photosynthetic electron transfer)
Term
chloroplast make Carbs with
Definition
energy from NADH and ATP (dark reaction or carbon fixation)
Term
Calvin Cycle (dark reaction)occurs in thylakoid
Definition
fixes Carbon using Co2 and with Ribulose 1,5 biphosphate to produce 2 3-phosphoglycerates. Regenerates Ribulose 1,5 biphosphate using ATP and NADH while producing 3 carbon carb, glycerate.
Term
Ribulose phosphate carboxylase
Definition
rubisco catalyzes catalzyes Calvin Cycle, most abundant protein on earth
Term
C4 plants (dark reaction)
Definition
in dry areas cuz pores close. C4 plants compartmenatilize Calvin cycle to bundle sheath cells. Mesophyll cells convert malate from Co2 and transport it to bundle sheath cells. Rubisco Oxidizes ribulose 1,5 biphosphate.
Term
Energy use in calvin cycle
Definition
uses 9 atp and 6 NADPH from 3 co2 to form 1-glyceraldehyde 3 phosphate
Term
Photosynthetic transfer step 1
Definition
photon energy is captured by antenna complex of chlorophyll which funnels electrons to its center which is the photochemical reaction center, whcih collects electron energy. IT also seperates an electron from H20 to produce hydrogen and oxygen
Term
Photosynthetic electron transfer step 2
Definition
Photon of light energizes electron in chlorophyll (photosystem II) Electron is transferred by resonance electrons transfer. The electron is replaced by removin electron from water. Manganese in proteins stabilize oxygen radicals created.
Term
photosynthetic electron transfer 3
Definition
photosystem II passes electron to plastiquinone, and then to cytochrome b6-f complex.cytochrome b6-f pumps an H+ to thylakoid space as it passes its electron to the second photosystem using plastocyanin
Term
Photosythetic Electron Transfer 4
Definition
photosystem I uses light energy from second photon to excite electron furhter. Electron is passed to ferrodoxin, and added to NADP+ +H by ferrodoxin NADP reductase. High energy NADPH is created, and AtP is created from protein gradient like mitochondria
Term
Dual System Evolution
Definition
evolved from precursors using H2S as electron Donor
Term
charge seperation
Definition
accomplished by two unique chlorophyll in photochemical reaction center, electrons are replaced by removing them from water.
Term
Actin structure
Definition
small globular, called gactin when unassembled. Actin filament is called f-actin, can be few micrometers in lenght.
Term
actin evolution
Definition
from small primitive prokaryotic cytoskeletal proteins. Mlb, MreB, or ParM
Term
actin motor proteins
Definition
transport cargo along actin and apply force to exterior
Term
Actin Assembly
Definition
Requires nucleation, forms trimer of Gactin, Atp which is hydrolyzed quickly after assembly, uses polarity
Term
barbed filament end
Definition
assembly of actin preferentially occurs also called + end
Term
pointed end
Definition
or - end, where disassembly occurs
Term
treadmilling
Definition
disassembly and assembly occur at same rate
Term
prolifin
Definition
promotes actin assembly
Term
thymosin B4
Definition
inhibits actin assembly
Term
ARP2/3 (actin related protein)
Definition
nucleates branched actin meshworks
Term
Gelsonin
Definition
CA++ activated regulates actin severin proteins and caps at severence
Term
cofilin
Definition
promotes actin instability by unwinding (actin turnover is 20x higher with cofilin presence)
Term
Cap Z
Definition
caps end of actin bundle and prevents subunit exchange
Term
Alpha Actinin
Definition
bundling protein that forms loose actin budles(muscle fibers) form dense plaque for cell membrane binding
Term
Vilin and Fimbrin
Definition
form tight actin bundles (microvilli)
Term
Spectrin, MyosinI and Erm family of proteins
Definition
actin associated proteins that interact with membranes to allow support of membrane structures by actin. (spectrin=plasma membrane, links blood to actin meshwork), microvilli (myosin I)
Term
Lamellar protrusion
Definition
activity of actin caused by CapZ ucapping, ARP 2/3 mediated assembly and cofilin mediated disassembly
Term
platelet activation
Definition
involves calcium mediated nucleation of filaments by gelsolin
Term
Cell Crawling
Definition
Actin anchors cell in cellcell cell substrate attachments, (cell junctions and focal adhesions.)
Term
RAS family of proteins
Definition
include Rac, rho, and cdc42 which are regulated by membrane receptors.
Term
Rac protein
Definition
stimulates lamellar protrusion
Term
Rho proteins
Definition
stimulate stress fiber formation
Term
CDC42 protein
Definition
stimulates filapod formation
Term
myosin superfamily
Definition
includes all actin motor proteins and have globular heads with actin activated ATPase activity and a variable tail domain
Term
Ischemia
Definition
alters actin cytoskeleton
Term
nucleation factors
Definition
reduce critical concentration for actin assembly
Term
FAK, focal adhesion kinase
Definition
for focal adhesion binding
Term
myosin atpase activity cycle
Definition
Atp binding releases myosin from actin
ATp hydrolysis moves myosin forward
release of ADP from myosin allows reattachment to actin, and release of ADP creates force for movement.
Term
Myosin VI
Definition
only myosin to move towards negative end.
Term
myosin tail modification
Definition
allows for different behaviors and cargos on myosin
Term
Contractile force generation
Definition
generated by action of bipolar myosin II thick filaments
Term
myosin II thick filaments
Definition
myosin dimers linked at their tails
Term
phophorylation of myosin light chains
Definition
form thick filaments in smooth muscle cells as needed
Term
skeletal muscles
Definition
large multinucleated cells containing thick filaments organized into permanent sarcomeres
Term
sarcomeres
Definition
dark binds=actin+myosin, light bands=actin
Term
nebulin protein
Definition
determines actin thin filament length in sarcomeres
Term
Z disc and Capz
Definition
the + ends of actin in sarcomere attach to z disc and are bound by capZ
Term
tropomodulin
Definition
bind and protect - end of actin
Term
titin
Definition
positions thick filaments
Term
regulation of smooth muscles contraction
Definition
phosphorylation of light chains
Term
regulation of smooth muscles contraction
Definition
phosphorylation of light chains
Term
regulation of smooth muscles contraction
Definition
phosphorylation of light chains
Term
regulation of smooth muscles contraction
Definition
phosphorylation of light chains
Term
sarcomere contraction regulation
Definition
regulated by calcium
Term
Calcium contaction regulation 4 steps
Definition
1.)nerve impulses induce depolarization of cell plasma membrane and transverse tubule system occurs first
2.)depolarization of transverse tubular stimulates release of calcium from sarcoplasmic ER (modified er)
3.) calcium binds troponin complex causing tropomysin to detach from actin
4.)myosin binding sites are revealed allowing contraction to occur
Term
Cell locomotion involves
Definition
protrusion, attachments, transport and retraction of trailing attachments
Term
protrusion
Definition
Lamellar protrusion is driven by cyclical actin polymerization at cell periphery, and cofilin dependent depolymerization at interior sites
Meshworks are assembled at edge of cels, by uncappin plus ends and filament branchin (ARP 3/2)
Meshworks are dissassemble by in interior by cofilin providing new subunits for assembly
Term
attachment
Definition
mediated by formation of focal adhesion
Term
Forward transport of organelles mediated by
Definition
motor protein myosin I and V transport toward + ends, and dyneins, and kinesins
Term
retraction of trailing cellular attachments is mediated by
Definition
myosin II concentrated at trailing end of motile cells
Term
structure of striated muslce cell
Definition
microfibrils with m-lines, z-lines, a bands, i bands, transverse tubules, and sarcoplasmic reticulum
Term
actin of striated muscles
Definition
ancohred in Z using alpha ACtinin, myosin assembled in thick filaments
Term
smooth muscle contraction initiation and actin stucture
Definition
activated by light chain kinase, causing mini myosin filaments to form, and structure is mesh anchored by alpha actinin in dense plaqus.
Term
tubulin dimer
Definition
made up of alpha and beta monomers, smallest unit of tubulin
Term
circumfrence and diameters of microtubules
Definition
13 subunits in circ, 24nm in diameter
Term
Microtubule associated proteins...
Definition
stabilize and bundle microtubules
Term
Tubulin
Definition
homolgous to FtsZ protein in bacteria, and is involved in division of bacteria, mitochondria and chloroplast
Term
Key features of microtubule assembly
Definition
disassembly and assembly occur at + end
assembly uses GTP
Beta subunit GTP is hydrolyzed which occurs shortly after assembly
GDP tubulin dissassembles readily
Term
GTP cap
Definition
protects growing microtubule, loss of cap creates catastrophe (disassembly)
Term
dynamic instability
Definition
growin and shrinkin microtubules present at same time too probe for targets like chromosomes
Term
microtubule treadmilling
Definition
rare!
Term
ends of microtubule
Definition
- end attaches to centrosome, and + goes searching in cell peripherary
Term
Microtubules nucleation occurs at
Definition
centrosome
Term
Centrosomes contain
Definition
two centrioles, supporting material and microtubule nucleation sites
Term
Rings of Gamma tubulin
Definition
nucleation sites
Term
special centrosome cases:plants, fungi, and neurons
Definition
plants and fungi lack centrioles, and in neurons microtubules can detach from centriole
Term
Stabilization of microtubules is done by
Definition
MAP, and phophorylated maps fall off and create less stable more dynamic microtubules
Term
MAP 2
Definition
makes loose bundles of microtubules
Term
Tau
Definition
involved in neurons and involved in alzheimers generates closely packed bundles
Term
Catastrophins
Definition
induce microtubule catastrophe, are phophorylated and activated during prophase.
Term
katanin
Definition
a catastrophin that cuts microtubules
Term
Stathmin
Definition
nonphoshporylated causes tubulin dimer splitting, and dephophorylation lowers effective tubulin concentration
Term
EB1`
Definition
associates with growing microtubule ends and helps them attach to target sites
Term
microtubule motors
Definition
microtubule dependent ATPases
Term
Dynein
Definition
- end tubular motor, involved in chromosome seperation, cillia and flagella movement,and moving organelles to cell center
Term
Kinesin
Definition
+ end kinesin motor, involved in mitochondria distribution, ER, pigment granules)
Term
motor inactivation
Definition
can be accomplished by phosphorylation
Term
6 steps of cell division
Definition
prophase, prometaphase, metaphase, anaphase, telophase, cytokinesis
Term
prophase
Definition
packagin of dna into chromosomes, membrane systems like golgi and mitochondria fragment and diffuse througout dividing cells
Term
prometaphase
Definition
nuclear membrane breakdown by phophorylation of laminins, formation of mitotic spindles, attachment of chromosome to spindle
Term
metaphase
Definition
allignment of chromosome, metaphase spindles are dynamically balanced at metaphase plate, - end directed motors pull chormosome poleward,
Term
anaphase
Definition
seperation and movement of chromosome to opposing spindles, seperation of spindles
Term
telophase
Definition
reconstruction of nuclear envelope
Term
cell division is proceded by
Definition
chromosome replication in interphase
Term
cell division is regulated by
Definition
M-CDK, cyclin and proteases like APC
Term
Cohesin
Definition
link sister chromatids during prophase, they are degraded during anaphase
Term
condensins
Definition
condense and package chromosomes
Term
astral tubules
Definition
position spindle in cell center during prometaphase
Term
interzonal tubules
Definition
build spindle, + end motors assemble spindle poles, and - end motors seperate spindle poles during prometaphase
Term
Kinetochore microtubuels
Definition
attach chromosome to mitotic spindle during prometaphase. and exhibit flux, a form of treadmilling during metaphase
Term
Kinetochores
Definition
- microtubule motors,and capture and stabilize microtubules, and move towards metaphase plate
Term
APC (anaphase promoting complex)
Definition
triggers anaphase, degrades M-CDK, and degrades inhibitory domain of seperase
Term
Seperase
Definition
cleaves cohesin subunit and leads to daughter chromosome seperation
Term
Anaphase A
Definition
Minus end directed microtubule motors move chromosome along kinetochores, kinetochore microtubules shorten at kinetochore and spindle pole
Term
Anaphase B
Definition
plus end microtubule motors slide interzonal microtubules apart, which elongate, - end motors pull on astral microtubules
Term
Deactivation of M-CDK
Definition
in telophase causes active phosphatases to reduce phosphorylation of proteins such as MAPs, actin associated proteins, nuclear lamin, this allows reformation of nucleus reattachment of cell to substrate
Term
cytokinesis in animals
Definition
contractile ring is formed in interzonal region which has actin and myosin II which create a cleavage furrow, which leads to a mid body of tightly pack tubules.
Term
cytokinesis in plants
Definition
a preprophase band of actin and microtubules is formed before mitosis and predicts the site of division. after chromosome seperation, microtubules called phragmoplast guides secretory vescicles with cell wall components to the division plane to form a cell plate, which forms new cell wall
Term
cilia and flagella move by
Definition
atp dependent dyneins sliding
Term
axoneme
Definition
microtubule structure that supports cilia
Term
cilia contain..
Definition
9 outer doublets of microtubules and i inner doublet known as 9+2 configuration
Term
outer doublet
Definition
contains complete microtubule which has dynein arm(A), and incomplete (B), and are linked to inner doublet by spoke proteins made of nexin
Term
inner doublet
Definition
surrounded by dense protein sheath
Term
cilia ends
Definition
+ end are at the end of cilia or flagella, - end are imbedded in cell
Term
cilia and flagella are nucleated from
Definition
centriole in embedded in cell cortex by actin and filaments
Term
centrioles
Definition
short barrel shapes of triplet microtubules abc, A is complete and b and c aren't
Term
How cilia move
Definition
dynein is anchored to A microtubule and the motor interacts with neighboring b microtubule. Atp causes neighbors to slide toward their plus ends. this movement is converted to a bending motion.
Term
Kinesin in cilia
Definition
move subunits to plus end for maintenance as old subuints are removed at the near end
Term
chlamydomonas
Definition
algae used for studying cilia and flagella
Term
intermediate filaments characteristics
Definition
easily bent but dont break, provide mechanical strength to cells often,and are specialized in function and aren't expressed in all cells of an organism
Term
Formation of intermediate filaments
Definition
two alpha helical domains form coil coiled dimer, which are linked head to tail to form tetramer, eight tetramers form intermediate filament. These can be bundled or crosslinked to make larger structures. Lateral interaction of IF makes them strong.
Term
assembly and disassembly of IF
Definition
assemble readily and disassemble by phosphorylation
Term
organization of IF occurs by
Definition
neurofilament IF can bundle itself, plectin can associate IF with actin and microtubules,organization regardless is dynamic and distribution is determined by microtubules
Term
nuclear lamins are
Definition
a major class of IF, found in nucleus and are regulated during cell cycle by phosphorylation
Term
Vimentin IF
Definition
mesechymal tissue is where it is found aka blood bone muscle, and form dense support network.
Term
desmin IF
Definition
found in all muscle typers, if desmin IF gene is broke, myopathies are caused, a genetic disorder in muscles
Term
Glial Fibrial acidic proteins (Glap)
Definition
found in astroglical cells which support the brain, like schwann cells
Term
Keratins IF
Definition
found in epithelial cells, and supports skin and structures like hair and nails. mutations of skin keratin cause blistering disease.keratin is formed from a basic and acidic monomer. over 15 of each monomer
Term
neurofilaments IF
Definition
found in neurons, play role in neurogenesis, dimers formed by L protein with an N or an H protein.neurofilament determines neuron size. irregular regulation contributes to lougherigs disease.
Term
occludan junctions...
Definition
regulate fluid across epithelial cell barriers
Term
anchoring junctions
Definition
provide strong attachment of cells to eachother and extracellular matrix
Term
communication junction
Definition
allow movement of ions and small signals between cells
Term
two types of occluden junctions
Definition
tight (vertebrate) and septate (invertabrates)
Term
function of occluden junction
Definition
variably permeable,regulate fluid across epithelial barriers, and functionally seperate apical membrane from basolateral membrane
Term
structure of occluden junction
Definition
branched network of contacts between cell membranes create sealing strand.
Term
homodimers of claudins and occludins
Definition
form sealing strand in tight junction
Term
disc large
Definition
form septae junction
Term
two classes of anchoring junctions
Definition
IF associated and actin assocciated
Term
actin associated anchoring junction two types and proteins involved
Definition
adherins junction (cell,cell)use cadherin in transmembrane and vinculin intracellularly
Focal adhesion (cell matrix):integrin in transmembrane and vinculin intracellularly
Term
IF associated anchoring junction, two types and proteins involved
Definition
Desmosomes:(cell,cell), use cadherin in transmembrane and desmoplakin or globin intracellularly
Hemidesmosomes:(cell matrix), use intergrins in transmembrane, and plectin intracellularly
Term
anchoring junction structure
Definition
intracellular anchor protein with transmembrane adhesion protein. IF are stronger. Junction can form isolated adhesion spots (macula adhesions, desmosomes,hemidesmosomes) or bands (zonula adherins)
Term
two classes of communication junctions
Definition
gap junction in animals and plasmodesmata in plants
Term
function of communication junction
Definition
allow signaling by small ions between cellls, permeability of gap junctions can be regulated
Term
gap junction structure
Definition
two connexons one from each cell, 6 connexin proteins form connexon
Term
plasmodesmata structure
Definition
channels of cytoplasm that join neighboring cells through holes in cell wall
Term
plasmatubules
Definition
ER derived membrane tubes in center of plasmodesmata
Term
integrins
Definition
calcium dependent adhesion molecules with that form heterodimers from 24 alpha subunits and 9 beta for adhesion specificity
Term
morphology of extracellular matrix
Definition
basal lamina and connective tissue
Term
extracellular matrix formed by
Definition
fibroblast, chondroblast, osteoblast
Term
composition of extracellular matrix
Definition
grounnd substance with embedded fibers
Term
ground substance types for extracellular matrix
Definition
glycosaminoglycans (gag), proteoglycans, glycoproteins
Term
glycosaminoglycans
Definition
long polysachirride, with negative which binds water and makes gel that resists compression, most common form is hyaluronic acid, a single linear molecule
Term
Proteoglycans
Definition
GAG linked with proteins, with for functions (space filling, molecular sieving, cell signaling including proliferation, and regulate extracellular proteins)
Term
glycoproteins
Definition
huge molecules that bind gag's, fibers, and cell surface receptors.
Term
fibronectin
Definition
glycoprotein, abundant in connective tissue, regulates cell adhesion and deletion cause fetal lethal mutation. Uses RGD to be recognized by integrins. can be remodeled by fibroblast
Term
Laminin
Definition
glycoprotein abundant in basal lamina and helps form it, recognized by epithelial integrins
Term
Collagen
Definition
25% of dry mass in collagen,strong as steel, 20 types.
Term
collagen synthesis
Definition
forms long monomer called pro-alpha collagen, in ER this is hydroxylated and glycosolated, which allows it to form trimer called procollagen.after secretion the proteins at the end are cleaved to make collagen non soluble
Term
Elastin
Definition
Fiber that makes elastic fibers, found in tissues that strethc like skin and arteries
Term
matrix proteases
Definition
allow cell migration, could be used antimetastatic therapies
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