Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

BCHM Exam 3 > Oxidative Phosphorylation > Flashcards

Oxidative Phosphorylation Flashcards

1
Q

Where does ox pho occur?

A

In the inner membrane of the mitochondria; bc the outer membrane in porous and the inner is impermeable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Reduced cofactors role in the electron transfer chain

A

NADH, NADPH, FADH; Electron carriers that donate their electrons to the electron transport chain on the matrix side

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Where do the reduced Cofactors need to go?

A

From the cytosol (intermembrane space to the matrix)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Malate-Apartate shuttle system in matrix

A

Malate is converted to oxaloacetate by malate dehydrogenase and NAD+ —-> NADH + H+ to produce one additional NADH in the matrix

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Malate-Asp shuttle system in the cytosol

A

Oxaloacetate is converted to malate by by malate dehydrogenase and NADH + H+ —> NAD+; produces one fewer NADH in the cytosol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the reason behind NADH having a higher concentration in the matrix than cytosol

A

NADH is too large to be efficiently transported into the matrix

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How do you move oxaloacetate back to the cytosol

A

By converting it to aspartate so it can be transported as Asp to be reconverted to Oxaloacetate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Where is ATP produced

A

In the matrix

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How are ADP and ATP moved across the inner membrane?

A

Using an antiporter driven by inner membrane potential; the matrix contains ATP (4 negative charges) and the cytosol contains ADP (3 negative charges) that allow flow of ATP to be exported into the cytosol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How is Pi imported into the matrix?

A

Via a symport driven by H+ gradient where there is lower H+ in the matrix

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Complex 1 NADH dehydrogenase

A

4 H+ are translocated into the cytosol for every 2 e- that pass through the complex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Electron path in NADH dehydrogenase

A

2 e- are released as NADH is oxidized; those e- are transferred to FMN; FMNH2 then passes the e- (one at a time) to a series of iron clusters until they reach Q to form Q2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is NADH characterized as

A

A water soluble mobile 2 e- carrier

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Flavins

A

Prosthetic group that can carry 1 or 2 e-

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Fe-S Clusters

A

Cysteines and inorganic sulfur carry 1 e- from FADH2 to Q

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Ubiquinone is characterized as

A

A lipid soluble, mobile 1 or 2 e- carrier

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Where else can the cell get QH2

A
  1. Sussinate dehydrogenase complex to produce FADH2
  2. From fatty acid oxidation from the acyl-CoA dehydrogenase rxn
  3. From Glycerol-3-Phosphate from the mitochondrial dehydrogenase reaction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Complex 3 Cytochrome bc1

A

Ubiquinol (QH2) donates 2 e- to complex 3, reducing cytochrome c; 4 H+ are transloacted into the cytosol for every 2 e- that pass through the complex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Cytochrome C

A

Mobile single electron carrier

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Cytochrome C

A

Mobile single electron carrier

21
Q

Complex 4: Cytochrome c oxidase

A

Cytochrome C proteins each donate 1 electron to complex 4, reducing the terminal electron acceptor O2.
2 H+ are transloaced into the cytosol for every 2 e- that pass through complex 4

22
Q

Cytochrome structure

A

Cytochromes are Proteins with heme group that are single electron carriers and 3 side groups on the heme

23
Q

Complex 1 reduction potential

A

-69.6

24
Q

Complex 3 reduction potential

A

-36.7 kj/mol

25
Q

Complex 4 reduction potential

A

-112 kj/mol

26
Q

What is oxidative phosphorylation regulated by

A

The availability of NADH and QH2

27
Q

Chemiosmotic Model

A

Combination of the H+ imbalance (due to e- transport) and the negative charges on the matrix side of the membrane results in an electrochemical gradient that factors H+ moving into the matrix

28
Q

F1

A

Soluble portion holding 3 alpha and 3 beta subunits each with synthase activity

29
Q

F0

A

Membrane spanning portion that includes a subunit where H+ enters and exits and a C ring

30
Q

C ring

A

Consists of 8-15 subunits that each bind an H+ to help rotate the ring

31
Q

Complex V (F1F0ATP Synthase)

A

H+ gradient is used to generate ATP where H+ move down their gradient by passing through ATP synthase; 1 ATP produced for every 4 H+ (no matter how many subunits are in the c-ring)

32
Q

Y subunit of complex V

A

Extends from F0 to F1 and rotates 120 degrees once enough strain has built up from the c ring rotation;

33
Q

Beta L confirmation

A

Loose; ADP+ Pi are bound

34
Q

Beta T conformation

A

Tight; ATP is formed

35
Q

Beta O conformation

A

Open; ATP is released

36
Q

What does one full rotation of the y subunit yield?

A

3 ATP (1 per each beta subunit)

37
Q

P:O ratio

A

Ratio of phosphorylations (ADP + Pi —> ATP) to oxygen atoms reduced (1/2 O2 + 2 H+ + 2 e- —>h20)

38
Q

How many H+ does NADH translocate?

A

Complex 1: 4 H+
Complex 3: 4 H+
Complex 4: 2 H+
Total = 10

39
Q

How many ATPs does NADH generate

A

10 H+ x (1 ATP/ 4H+)= 2.5 ATP (PO ratio)

40
Q

How many H+ does QH2 oxidation translocate?

A

Complex 3: 4 H+
Complex 4: 2 H+
Total = 6

41
Q

How many ATP does QH2 generate

A

6 H+ x (1 ATP/4H+)= 1.5 ATP (PO ratio)

42
Q

What does oxygen consumption indicate

A

That electrons are moving through the electron transport chain

43
Q

How does CN- target oxidative phosphorylation?

A

It blocks e- transport through complex IV therefore shutting down the entire e- transport chain and preventing the formation of the H+ gradient

44
Q

Role of Ventruicidin and oligomycin

A

They block the H+ channel in ATP synthase which causes the ETC to slow down as the H+ gradient gets too steep (doesn’t stop completely some H+ still leak)

45
Q

Role of succinate

A

May be added to mitochondria to generate QH2

46
Q

What does O2 consumption indicate?

A

Electron transport is working

47
Q

What does ATP synthesis imply?

A

That protons are moving through ATP synthase

48
Q

Uncoupling protons

A

Can uncouple oxidative phosphorylation and provide a path to bring H+ down their concentration gradient without passing through ATP synthase; free energy in this process generates heat and can denature proteins

49
Q

How many translocated protons does it take to make 1 ATP

A

4 H+ make 1 ATP

BCHM Exam 3 (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions