Brainscape's Knowledge GenomeTM

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


See full index

Biochemistry > Week 7: ETC > Flashcards

Week 7: ETC Flashcards

1
Q

What are the 4 compartments of the mitochondria?

A
  1. Outer membrane
  2. IMS
  3. Inner membrane
  4. Matrix
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the purpose for the outer membrane of the mitochondria?

A
  1. Relatively porous membrane that allow passage of metabolites
  2. It also allow movement for phosphate, CAC components, ADP and ATP
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the purpose for the intermembrane space (IMS) of the mitochondria?

A

Similar environment to cytsol that has a higher proton concentration

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

What is the purpose for the inner membrane of the mitochondria?

A
  1. Impermeable to ions and polar molecules
  2. Location of the ETC and ATP synthase complexes
  3. Contains transporters for specific compounds
  4. Contains cristae
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the purpose for the matrix of the mitochondria?

A
  1. Location of the CAC and parts of lipid and amino acid metabolism
  2. Has a lower proton concentration
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

In what ways is the ETC considered a serious of coupled redox reactions?

A
  1. Electrons flow from NADH to O2 by large protein complexes
  2. Acts as a bucket brigade for e- carriers
  3. Facilitate rapid transfer of substrate while preventing intermediates from forming
  4. FADH2 electrons feed in after NADH it has lower reduction potential
  5. Fe is a prosthetic group for each protein in the ETC
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Where do the electrons for the ETC come from?

A

Matrix side of mitochondria

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

Can reduced coenzymes cross the inner mitochondrial membrane?

A

No it needs a shuttle

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

What are the two methods of feeding electrons from NADH in cytosol into the mitochondria?

A
  1. Malate-aspartate shuttle

2. Glycerol-3-phosphate shuttle

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

What is the purpose of Coenzyme Q?

A

Lipophillic shuttle that carries electrons and H+ from the inside of the mitochondria to the IMS

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

Which complex is also a part of the CAC?

A

Complex II

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

How many electrons are transferred from NADH to coenzyme Q?

A

2

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

What occurs during Complex I?

A
  1. NADH-Ubiquinone Oxidoreductase
  2. NADH → FMN → Fe-S → Coenzyme Q
  3. Coenzyme Q is reduced to QH2
  4. 4H+ is released from matrix to IMS
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What occurs during Complex II?

A
  1. Succinate dehydrogenase also a part of CAC
  2. Succinate transfers 2e- to FAD → SD reduces FAD to FADH2 → FADH transfer 2e- to Fe-S → Fe-S trnasfers 2e- to Coenzyme Q
  3. Coenzyme Q reduced to QH2
  4. Reduction of FAD to FADH2
  5. Oxidizes succinate to fumerate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What occurs during Complex III?

A
  1. Coenzyme Q transfers electrons to III
  2. Complex III contains 2 cytochrome c (can accept electrons) and transfers 2 electrons
  3. Cytochrome c shuttles e- to Complex IV?
  4. 4H+ are transferred to IMS
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What occurs during Complex IV?

A
  1. Catalyzes the formation of water from e-, H+, and O2
  2. Every 2e- that are transferred, 2H+ are translocated to IMS
  3. O2 reacts with 2H+ from matrix to form water
  4. Protons transferred across membrane create pH gradient
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How is a proton gradient generated for ATP synthesis?

A

The ETC uses energy released from electrons to pump H+ to the IMS

18
Q

What are the pathways that comprised cellular respiration?

A

CAC and oxidative phosphorylation

19
Q

What is cellular respiration?

A

An ATP generating process where O2 serves as an electron acceptor

20
Q

Where would the electrons of the ETC flow?

A

4 protein complexes embedded in the IMM

21
Q

What coenzymes donate electrons to O2 during ETC?

A

NADH and FADH2 are oxidized reducing O2 to H2O

22
Q

Is the reduction of O2 exergonic or endergonic?

A

Exergonic

23
Q

Why is NADH considered a strong reducing agent?

A
  1. Ready to donate electrons

2. Negative reduction potential

24
Q

Why is O2 considered a strong oxidizing agent?

A
  1. Ready to accept electrons

2. Positive reduction potential

25
Q

How many protons are used for ATP synthase?

A

4H+

26
Q

How much ATP does FADH2 make?

A

1.5ATP

27
Q

How much ATP does NADH make?

A

2.5ATP

28
Q

What is the difference between synthase and synthetase?

A

Synthetase uses ATP, synthase can make ATP

29
Q

What is the importance of mitochandrial structure in regards to ATP production?

A
  1. E- pass through Complexes I, III, and IV leading to the pumping of protons from IMM to matrix to IMS creating a pH gradient
  2. The difference between the H+ concentration in matrix and IMS is the basis of coupling between oxidation and phosphorylation
  3. The proton gradient is the source of energy to drive ATP synthase
30
Q

What occurs during Complex V?

A
  1. 4 Protons go down its gradient to drive ATP synthase
  2. Phosphate joins ADP to make ATP
  3. ATP is synthesized in the mitochondria then translocated to the cytoplasm by a cotransporter that simultaneously brings ADP into the mitochondria
31
Q

How do we make ATP with the reaction is thermodynamically unfavorable?

A
  1. Reduced substrate donates e-
  2. ELectron carriers pump H+ out as e- flow to O2
  3. Energy of e- flow stored as electrochemical potential
  4. ATP synthase uses electrochemical potential to synthesize ATP
32
Q

How is ADP and Pi translocated to the matix?

A

Translocase proteins located in the inner mitochandrial matrix

33
Q

What are the 2 translocase proteins that translocate ADP and Pi?

A
  1. Adenine nucleotide translocase: the export ATP for every ADP imported
  2. Phosphate translocase: translocates on Pi and 1H+ into the matix
34
Q

What occurs when oxidative phosphorylation lacks O2?

A

No ATP is genreated

35
Q

What are the three factors that reguate oxidative phosphorylation based on its availabilty?

A
  1. NADH
  2. ATP
  3. ADP/Pi
36
Q

How does high NADH effect the oxidative phosphorylation?

A

High NADH/NAD+ ratio inhibits dehydrogenase reaction of CAC (high energy state)

37
Q

How does high ATP effect the oxidative phosphorylation?

A

Increased ATP inhibits glycolysis and CAC (high energy state)

38
Q

How does high ADP/Pi effect the oxidative phosphorylation?

A

Activates glycolysis, CAC and respiratory chain (low energy state)

39
Q

How does high NADH inhibit oxidative phosphorylation?

A

Causes feedback inhibition cascade up to pyruvate kinase in glycolys

40
Q

What causes the formation of ROS during oxidative phosphorylation?

A

Coenzyme Q is naturally leaky and facilitates partial reduction of Complex III targets where single e- transfers result in free radicals

41
Q

What are the overall reactions that convert free radicals to H2O?

A
  1. Superoxide dismutase converts free radical to H2O2
  2. NADPH from PPP reduces glutathion eliminating toxic free radicals
  3. H2O2 is converted to H2O by glutathione peroxidase
42
Q

What type of force is used to drive the sythesis of ATP in OP?

A

Electrochemical proton-motive force

Biochemistry (16 decks)

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