MidTerm 2 Flashcards
roles of actin
muscle fibers
microvilli
projections (gut)
roles of microtubules
mechanical support cytoplasm organization transport motility - digestion chromosomal segregation
intermediate filaments
lamins
structural
subunits of actin
G-actin monomer
F-actin fibers
Arp2/3 - nucleating/branch
formin - nucleating/head
subunits of microtubules
aB heterodimers G turc centrosome GTP tubulin GDP tubulin cap of GTP tubulin
_______ is hard, _________ is easy
nucleation, elongation
intermediate filaments subunits
monomer
coiled-coil dimer
staggered tetramer
two tetramers
intermediate filament polarity (micro/macro)
polar/ non-polar
microtubule polarity (micro/macro)
polar/polar
actin polarity (micro/macro)
polar/polar
nucleating element of microtubules
G turc
nucleating element of actin
formin and Arp2/3
myosin walks on _______ in the ______ direction
actin , positive
formin adds subunits to the _____ end, and then filament extends to the ______ direction, and grows to the ______ direction
positive, negative, negative?
what causes dynamic instability?
the GTP tubulin dimers hydrolyze into GDP, and lose stability
what are the benefits of dynamic instability?
“search and capture” mode, where they explore until they find their destination
microtubule motor proteins and direction
dynine - negative
kinesin - positive
dynine purpose
motor protein, carries vesicles etc., cilia, flagella
kinesin purpose
motor protein, axonal transport etc.
what role does actin play in mitosis?
the contractile ring
what role do microtubules play in mitosis?
chromosomal organization
myosin power stroke steps
- release - ATP binds
- reach - ATP hydrolysis
- bind - Pi released
- power stroke - ADP released
another name for H+
proton
if you remove an electron from hydrogen, you get…
a proton
H+ is purely____
acidic
pH stands for ______
power of hydrogen
pH of 7 is _____
neutral
hexokinase
enzyme that catalyzes breakdown of glucose to glucose 6 phosphate
substrates can bind through what bonds
ionic, hydrogen and covalent
a catalyst will ______ a reaction
speed up
does catalysis change delta G
no
two factors that determine the rate of a reaction
activation energy and concentration
an irreversible reaction has a _____ delta G going backwards
positive
if a reaction is reversible, it’s likely that delta G is _________
very small
reversible reactions generally proceed in the direction of _________
lower concentration
Glycolysis input
glucose, 2 ATP, 2 NAD+
Glycolysis output
2 pyruvate, 4 ATP, 2 NADH
Glycolysis location
cytoplasm
Fermentation input
2 pyruvate, 2 NADH
Fermentation output
2 lactate, 2 NAD+
Fermentation location
cytoplasm
CAC input
acetyl CoA / oxaloacetate, FAD, GDP, 3 NAD+
CAC output
3 NADH, 1 FADH2, 1 GTP, 2 Co2
CAC location
matrix
ETC input
NADH, FADH2 (electrons)
ETC output
ATP, NAD+, FAD
ETC location
inner mito. membrane
Glucose carbon number
6
Fructose 1,6 biphosphate carbon number
6
G3P carbon number
3
1,3 BPG carbon number
3
pyruvate carbon number
3
acetyl CoA carbon number
2
oxaloacetate carbon number
4
citrate carbon number
6
ketogenesis
starvation response, triggered by glucagon
does ketogenesis make the blood acidic?
YES! it releases ketones, which are acidic
3-phosphoglycerate number of carbons
3
citrate carbon number
6
to get G3P molecules we______
isomerize
citrate is made from _____ + ______`
acetyl CoA + oxaloacetate
poly uria
excessive urination
polydipsia
excessive thirst
polyphagia
increased appetite
are intermediate filaments polar
subunits yes, but not the macro
hexokinase
enzyme that phosphorylates hexoses (glucose) , making glucose 6-phosphate
TGF Beta downstream and role in dev
influence gene expression as tf, stimulates cell growth
WnT downstream and role in dev
gene expression as tf, cell-cell adhesion(bcat-cadherin), cell polarity (frizzled –> rho–>actin)
Hh (hedgehog) downstream and role in dev
gene expression as tf, limb bud diff, floorplate formation of neural tube
Nodal
TGF beta signal that is involved in left/right determination
GPCR downstream and role in dev
ion channels in neurons, gene regulation through other proteins ex: odorants, adrenaline, glucagon
what signal pathway does glucagon use?
GPCR (G protein)
adrenaline pathway
GPCR
RTK (receptor tyrosine kinase) downstream and role in dev
cell cycle control, changes in expression, ie insulin other mitogens
is insulin a mitogen
yes
name one mitogen
insulin
Delta/Notch downstream and role in dev
cell differentiation around neurons, gene expression by tf, keeps adjacent cells from becoming neurons
phosphoglycerate kinase
enzyme for ADP to ATP or reverse
ATP synthhase
enzyme that generates ATP in the ETC from the proton electrochemical gradient. It acts like a hydraulic generator, spinning a wheel with the protons and generating ATP from ADP
proteins destined for the plasma membrane have what kind of sequences?
“stop and/or start transfer” sequences
If you tmp has its N terminus in the cytoplasm, does it have a signal sequence?
no
Can you have two start/stop sequences in a row, in a tmp?
no
proteins destined for the cytosol are translated by what kind of ribosomes?
free ribosomes
proteins destined for a plasma membrane or for secreation are translated associated with what organelles?
ribosomes attached to the ER
What directs the polypeptide and its associated ribosome to the ER membrane?
SRP (signal recognition particle) binds to the signal sequence on the polypeptide and directs proteins to the ER
What is the cytochrome oxidase complex and what does it do?
3rd step in ETC, located in the inner membrane of mitochondria. Is an active transporter, moving protons into the inter membrane space against the electrochemical gradient
How does cyanide break respiration?
Cianide inhibits the cytochrome oxidase complex in step 3 of ETC, which eventually inhibits NADH production in the CAC, halting the ETC and leading to a decrease in ATP production
what binds the cells in cell-cell adhesion?
cadherin
the protein from the WnT signal, beta-catenin, also activates _______, a molecule that provides cell-cell adhesion
cadherin
cadherin
molecule that binds cells in cell-cell adhesion
protease that cleaves notch
presinilin
presinilin
protease that cleaves notch
APP
alzheimers precursor protein
how does presinilin lead to alzheimers
mutated presinilin cuts APP in the wrong spot, so it doesn’t degrade, and instead collects and forms amyloid plaques
cadherin is involved in _______ junctions
desmosome
Frizzled activates Rho and causes
cell polarization
what causes cell polarization
Frizzled activates Rho
what do APC and APC have in common?
they both degrade their target
desmosome
connecting fibers between cells
