Lecture 4 Flashcards
1
Q
Another name for ATP synthase
A
Complex V
2
Q
What is ATP synthase responsible for
A
Generating ATP
3
Q
You produce the same amount of ATP as ____ in a single day
A
Your weight
4
Q
How is F0F1 ATPase portrayed
A
Globular protein with a transmembrane region
5
Q
What is ATP produced from
A
ADP and inorganic phosphate
6
Q
Major regions of ATPase
A
F0 and F1
7
Q
How many subunits in F1
A
5
8
Q
How many subunits in F0
A
3
9
Q
___ is similar in size to the F1 region
A
Complex I
10
Q
Is F0F1 ATPase the only type of ATPase
A
No
11
Q
Other types of F0F1 ATPase
A
E1E2 ATPase and V ATPase
12
Q
Type of E1E2 ATPase
A
Na+/K+ pump
13
Q
Type of V ATPase
A
Vacuole H+ pump
14
Q
Function of Na+/K+ pump
A
Work under ATP hydrolysis (break it and harness the energy to perform useful work)
15
Q
Function of V ATPase
A
Pump protons
16
Q
Where is V ATPase located
A
Vacuole
17
Q
ATPases are energy-dependent ____
A
Ion pumps
18
Q
ATPases have reversible function depending on ___
A
The environment
19
Q
Similar features that all ATPases share
A
- Ability to reverse
- Series of shared structures
20
Q
Shared structures that ATPases have
A
F1 analog and F0 analog
21
Q
The overall function of ATPase is to throw the equilibrium between ___ and ___ out of balance
A
ATP and ADP
22
Q
Proportion of products versus reactants
A
Mass action ratio
23
Q
Use ___ to maintain mass action ratio away from equilibrium
A
Delta P
24
Q
ATPase sustains ____
A
Mass action ratio
25
ATPase sustains the mass action ratio __-__ orders of magnitude away from equilibrium
7-10
26
What does sustaining the mass action ratio lead to
Thermodynamic favoring reaction
27
What do thermodynamic favoring reactions produce
ATP
28
What was studied to examine ATPase
Submitochondrial particles (SMPs)
29
What are SMPs
Reconstituted membrane regions of the mitochondria that allow researchers to evaluate the functions of proteins
30
Most SMP have ___ structure
Inverted membrane structure
31
Inverted membrane structure
Matrix facing outside and inner portion represents cytoplasmic side
32
What is the benefit of inverted membrane structure
Further manipulation of proteins
33
In the inverted membrane structure, F1 faces the ___
Matrix
34
Where is ATP generated and hydrolyzed
Matrix
35
What did early studies treat SMP with
Urea and kealating agents
36
What is the effect of urea treatment on SMP
Some F1 regions knobs were lost
37
What happens when F1 knobs are lost
SMPs cannot synthesize ATP without them
38
How did F1 get its name
First fraction (F1). Called the first fraction because it was the first lost
39
Can protons still be channeled through the membrane when F1 is lost
Yes
40
What are membrane channels inhibited by
Oligomycin
41
What does oligomycin manipulate
F0
42
How did F0 get its name
Stands for oligomycin fraction
43
F1 subunits kDa
370
44
F1 subunits
alpha 3, beta 3, gamma, epsilon, sigma
45
F0 subunits kDa
160
46
F0 subunits
Transmembrane alpha helices; 9-12 c subunits, 2b, and 1 a subunits
47
___ and __ subunits interact, transferring rotation from F0 to F1
C and gamma
48
Gamma is the rotor that connects __ and __
F1 and F0
49
What is the C ring composed of
Alpha helices
50
What happens to the C ring as protons are translocated from intermembrane space into a and c subunits and then matrix
C ring rotates
51
After rotation of the C ring, there is a transfer of torq through the ___ subunit
Gamma
52
What does the transfer of torq cause
Gamma to rotate on its axis
53
Rotation of gamma triggers changes in the shape of ____
Alpha and beta subunits
54
How many subunits in the C ring
About 10, estimated 9-12
55
Inhibitor protein can interact with ___ and inhibit ____
Beta subunits
| Formation of ATP
56
Why is inhibitor protein present under natural conditions
So reaction does not run backwards (controls reversible function of ATPase)
57
How to reverse a reaction
Change the abundance of products versus reactants (MAR)
58
What does it mean when a ATP synthase reaction is reversed
Turn ATP synthases into an ATP hydrolyzing machine
59
___ allows the gamma subunit to rotate as ATP is hydrolyzed
Anchored F1
60
How to record gamma subunit rotation
- Remove F1 region and manipulate it to attach actin filament to gamma subunit
- Actin filament contains a fluorophore
- Record movement of actin filament under given conditions
- Tag F1 subunit with histidine group to attach it to a cover slip
61
How many revolutions of gamma per second
130
62
What subunits are active sites for ATP synthesis
3 beta subunits
63
___ ATP hydrolyzed per second
390
64
Where does catalytic formation occur
beta subunit
65
F0 rotates as a product of ___
H+ translocation
66
Gamma subunit is twisted by ___
F0
67
Rotational force of gamma subunit translates to conformational changes in _____
a and b subunits
68
Where does catalytic formation occur
3
69
Is the gamma subunit center
Usually a little off center
70
Changing shape of alpha and beta subunits leads to ___
Interaction of subunits with ADP and inorganic phosphate
71
How many times does the rotation cycle complete
3
72
ATP stores energy in the form of ____
High energy phosphate group
73
Composition of ATP
Adenosine ring with a chain of 3 phosphate groups attached
74
How is energy released from ATP
The last phosphates can be split off to release the energy within the bond
75
What are the resulting products of breaking of ATP
ADP and inorganic phosphate
76
Mitochondria make ___ kg of ATP a day in an adult
60
77
How many motors are in ATP synthase
2
78
Motors of ATP synthase
F1 and F0
79
Where is F0 located
Within the membrane
80
Where is F1 located
At the top
81
F0 is __ powered
Proton
82
What is proton flow driven by
pmf
83
How is F0 proton powered
Protons flow through a channel open to just the intermembrane space where they bind to a ring of protein subunits, rotate 360 degrees, and exit through another channel exposed only to the matrix
84
Torq is generated by ___ and transferred to __ by ____
F0
F1
Central stalk
85
___ is responsible for generating ATP by adding phosphate to ADP
F1
86
Conformation changes of catalytic subunits caused by
Rotation
87
Catalysis occurs at the interface between ___
Dimers
88
Three distinct states of ATP synthesis
1. ADP and phosphate bind to the catalytic site, and the central staff rotates 120 degrees to rearrange the molecules
2. Enzyme undergoes a further 120 degree rotation, and ADP and P are fused together to produce ATP
3. Enzyme rotates again to return to starting position, where ADP is released, and ADP and P can be bound for the next cycle
89
Catalytic subunits must remain stationary with respect to ____
Rotating central shaft
90
How are catalytic subunits kept stationary
Scaffold on the outside of the complex (peripheral stalk)
91
Is the peripheral stalk dynamic
Yes (can accommodate)
92
What does ATP synthase dimerize to shape the mitochondrial inner membrane into
Signature cristae shape
93
Purpose of signature cristae shape
Turbo charges ATP synthase by focusing proton gradient near ATP synthase
94
Complexes are in very close proximity to ____
ATP synthase
95
Can ATP synthase interact with each other
Yes, they can dimerize
96
Where is ATP synthase highly concentrated
In regions where ETS complexes are most abundant
97
Why is ATP synthase highly concentrated in regions where ETS complexes are most abundant
Helps to take advantage of electrochemical and proton gradient
98
What membrane does the lipid mosaic model apply to
Inner membrane
