MidTerm 1 Flashcards
1
Q
subunits of actin
A
G-actin monomerF-actin fibersArp2/3 - nucleating/branchformin - nucleating/head
2
Q
if a reaction is reversible, it’s likely that delta G is _________
A
very small
3
Q
How do cells overcome the activation barrier for reactions?
A
a catalyst!!
4
Q
hexokinase
A
enzyme that catalyzes breakdown of glucose to glucose 6 phosphate
5
Q
can the delta G from two reactions be added together
A
yes! if they’re coupled
6
Q
does NADH have a higher affinity for electrons than O2?
A
no
7
Q
How do enzymes maintain specificity?
A
they have unique structures and binding sites for subsrates
8
Q
anion
A
+electrons
9
Q
what downstream enzyme inhibits M-Cyclin
A
APC
10
Q
what role does actin play in mitosis?
A
the contractile ring
11
Q
can phosphorylation inhibit?
A
yes
12
Q
nucleating element of actin
A
formin and Arp2/3
13
Q
an irreversible reaction has a _____ delta G going backwards
A
positive
14
Q
myosin walks on _______ in the ______ direction
A
actin , positive
15
Q
dynine purpose
A
motor protein, carries vesicles etc., cilia, flagella
16
Q
what does delta G predict?
A
possibility/spontanaeity
17
Q
3 ways an enzyme catalyzes (lowers activation barrier) of a substrate
A
- binds 2 substrates and orients2. binds and reorients electrons of 1 substrate3. binds and strains / conforms 1 substrate to favorable transition state
18
Q
formin adds subunits to the _____ end, and then filament extends to the ______ direction, and grows to the ______ direction
A
positive, negative, negative?
19
Q
pH stands for ______
A
power of hydrogen
20
Q
intermediate filaments
A
laminsstructural
21
Q
types of cell energy
A
ATP, GTP, NADH, FADH2, pyruvate, acetyl coa
22
Q
4 major molecules in human body
A
carbohydrates, lipids, proteins, nucleaic acids
23
Q
reversible reactions generally proceed in the direction of _________
A
lower concentration
24
Q
a catalyst will ______ a reaction
A
speed up
25
Some enzymes require non-protein _________ for activity
cofactors
26
a molecule that resembles a substrate, and fills active/binding pocket without catalyzing a reaction is a __________
competitive inhibitor
27
malonate _______ succinate hydrogenase by filling its active site and preventing the conversion of succinate to fumarate
inhibits
28
where does phospholipid synthesis take place?
endoplasmic reticulum
29
in a normal resting states, humans use which process to re-generate the majority of their NAD +
ETC --- > ATP and NAD+, FAD
30
what are the benefits of dynamic instability?
"search and capture" mode, where they explore until they find their destination
31
examples of co-factors
vitamins etc.
32
roles of actin
muscle fibersmicrovilliprojections (gut)
33
covalent bond
two atoms share electrons (valence electrons)
34
catalysis
speeding a reaction by lowering the activation barrier
35
ionic bond
electrostatic attraction between 2 oppositely charged ions - result of transfer of electrons from one atom to the other
36
_______ is hard, _________ is easy
nucleation, elongation
37
does delta G predict rate?
NO
38
intermediate filaments subunits
monomercoiled-coil dimerstaggered tetramertwo tetramers
39
non-polar covalent bond
equal/balanced sharing of electrons
40
two types of catalytic enzyme inhibition
allosteric (regulatory site binding) and competitive (active site binding)
41
polar covalent bond
unequal sharing of electrons, causing partial ionic charge
42
where does the CAC take place
the mitochondrial matrix
43
Enzymes can be _______ by molecules that resemble the substrate
inhibited
44
catabolism
energetically favorable reactions
45
pH of 7 is _____
neutral
46
H+ is purely____
acidic
47
substrates can bind through what bonds
ionic, hydrogen and covalent
48
myosin power stroke steps
1. myosin bound to actin2. ATP binds to myosin, myosin releases3. ATP hydrolyzed, myosin returns to resting position4. cross bridge forms, and myosin head binds to new position on actin5. P released, myosin heads change conformation, causing power stroke, filaments slide past eachother6. ADP release, and myosin remains bound to actin.
49
anabolism
energetically unfavorable reaction
50
another name for H+
proton
51
AC - ref GPCR
adenylyl cyclase
52
a product is made from a ______
reactant
53
providing ______ can be helpful for patients with methanol poisoning
ethanol
54
does catalysis change delta G
no
55
what's an enzyme?
a highly specific catalyst
56
where does glycolysis take place?
cytoplasm
57
microtubule motor proteins and direction
dynine - negativekinesin - positive
58
AP ref - RTK
adaptor protein
59
APC (ref cell cycle )
anaphase promoting complex
60
the lipid present in Wnt does what?
helps bind it to it's origination cell
61
roles of microtubules
mechanical supportcytoplasm organizationtransportmotility - digestionchromosomal segregation
62
a kinase _____ a substrate
phosphorylates
63
nucleating element of microtubules
G turc
64
catabolism
glucose --> glycolysis or citric acid cycle
65
what motor proteins make sperm swim?
dynein motor proteins
66
is ATP stored?
no! it's continuously generated
67
RAP ref- rtk
ras activating protein
68
subunits of microtubules
aB heterodimersG turccentrosomeGTP tubulinGDP tubulincap of GTP tubulin
69
actin polarity (micro/macro)
polar/polar
70
are carbons oxidized to C02 in the CAC
yes
71
how do enzymes work?
they lower the activation energy of their substrate , catalyzing a reaction
72
intermediate filament polarity (micro/macro)
polar/ non-polar
73
types of bonds that determine protein and enzyme structure:
electrostatic attractionsvan der Waals attractionshydrogen bond
74
can phosphorylation activate?
yes
75
a reactant makes a ______
product
76
3 activities powered by ATP hydrolysis
pumping/transportmovement/mechanicalbiosynthetic
77
can the CAC occur in anaerobic conditions?
no, it indirectly requires O2
78
cation
-electrons
79
what role do microtubules play in mitosis?
chromosomal organization
80
polar molecule
resulting from polar bonds, asymmetric electron sharing
81
APC (ref - wnt)
adenomatous polyposis coli)
82
what causes dynamic instability?
the GTP tubulin dimers hydrolyze into GDP, and lose stability
83
the inhibition/degradation of securin leads to ______
anaphase
84
two factors that determine the rate of a reaction
activation energy and concentration
85
polar molecules are hydro_______
philic
86
motif/scheme of signaling pathways
1. signal reception - on receptor, in or out2. relay mechanism - pathway/cascade3. downstream effects - on effector, what happens?
87
microtubule polarity (micro/macro)
polar/polar
88
kinesin purpose
motor protein, axonal transport etc.
89
A ______ helps cells overcome activation barriers
catalyst
90
the hydrophobic portions of amino acids is typically found in/on the _________ of the conformation
inside
91
APC ubiquitinates both ______ and _______
M-Cyclin, Securin
92
sperm are made of _______ exoskeletal component
microtubules
93
if you remove an electron from hydrogen, you get...
a proton
94
non-polar molecules are hydro_______
phobic
95
are enzymes and substrates bound by covalent bonds?
NO!
96
active transport
movement of molecules against the electrochemical gradient
97
passive transport
movement of molecules down the electrochemical gradient
98
channel protein
channel that facilitates transport without a major conformational change
99
symport
two proteins moving through one
100
opposite of channel protein
carrier or transporter protein
101
is a uniport a channel or carrier?
can be both
102
is a symport a channel or carrier?
carrier
103
is a symport passive or active?
both, a symport will usually have one solute that's moving down the electrochemical gradient, while another is moving up
104
is an antiport passive or active?
both! An antiport will facilitate one molecule moving against the gradient, powered by one molecule moving down the gradiet
105
is an antiport a channel or carrier
carrier
106
Rab proteins
proteins on the cytoplasmic face of vesicle that provide the address code for interaction with correct target membrane
107
Where is the V-snare?
on the vesicle
108
where is the T- snare?
on the target membrane
109
what docks to the Rab?
tethering proteins
110
endocytosis
taking in of a vesicle
111
exocytosis
exportation of vesicle
112
dynamin
pinches off vesicle bud neck during exocytosis
113
clathrin coat
coat of vesicle that buds off
114
adaptin
barrier between clathrin coat and cargo receptor
115
kinesin movement
huge conformational change, moves it's back head forward/"forward step" / power stroke
116
how does ATP affect myosin
it causes it to release
117
M-Cyclin ________ MCdk
activates
118
are the levels of MCdk in the cell variable
no
119
are the levels of M-Cyclin in a cell variable
yes
120
how does G protein stop the formation of cancer cells
G protein has inherent GTPAse activity. Can hydrolyze GTP--> GDP and become switched off, so it's not constantly active.
