Biological Oxidation Flashcards Preview

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Flashcards in Biological Oxidation Deck (37):
1

The outer membrane of mitochondria have pores that make it permeable to small molecules and ions, but not proteins. True or false?

true

2

The inner membrane of a single liver mitochondria may have more than ___ sets of electron-transfer systems and ATP synthase molecules

10K

3

The heart muscle mitochondria contains __ X more electron transfer systems than liver mitochondria

3

4

Muscle and liver mitochondria are about the size of a bacterium __-__ um long

1-2

5

Each complex in the ETC contains multiple ___ centers

redox

6

Coenzyme Q is a mobile electron carrier transporting electrons from complexes ___ and ___ to complex __

1; 2; 3

7

Cytochrome c is the second mobile electron carrier. It carries a single electron from the cytochrome ___ complex to cytochrome ___

bc1; oxidase

8

What is the name for complex I and what does it do?

NADH-UQ oxidoreductase: catalyzes transfer of e- from NADH to UQ or CoQ

9

What is the name for complex II and what does it do?

succinate-ubiquinone oxidoreductase or succinate dh: transfers e- from succinate to CoQ

10

What is the name for complex III and what does it do?

cytochrome bC1 complex: transfers e- from ubiqunol

11

What is the name for complex IV and what does it do?

cytochrome c oxidase: transfers e- from cytochrome c to O2

12

What is the name for Complex V and what does it do?

ATP synthase: uses energy of the electrochemical gradient for synthesis of ATP

13

For the following compound, give its target/mode of action towards inhibiting the ETC:
cyanide, carbon monoxide

inhibit cytochrome oxidase

14

For the following compound, give its target/mode of action towards inhibiting the ETC:
Antimycin A

blocks electron transfer from cytochrome b to cytochrome c

15

For the following compound, give its target/mode of action towards inhibiting the ETC:
myxothiazol, rotenone, amytal, piercidin A

prevent electron transfer from Fe-S center to ubiquinone

16

For the following compound, give its target/mode of action towards inhibiting the ETC:
DCMU

competes with Q for binding site in PSII

17

For the following compound, give its target/mode of action towards inhibition of ATP synthase:
Aurovertin

inhibits F1

18

For the following compound, give its target/mode of action towards inhibition of ATP synthase:
Oligomycin, Venturicidin

inhibits F0 and CF0

19

For the following compound, give its target/mode of action towards inhibition of ATP synthase:
DCCD

blocks proton flow through F0 and CF0

20

For the following compound, give its target/mode of action towards inhibition of ATP-ADP exchange:
atractyloside

inhibits adenine nucleotide translocase

21

Complex I catalyzes the transfer of a hydride ion from ___ to ___, from which 2e- pass through a series of Fe-S centers to the Fe-S center N-2

NADH; FMN

22

Complex I is one of the largest macro-molecular assemblies in the mammalian cell with over ___ different polypeptide chains, encoded by both nuclear and mitochondrial genes

40

23

Succinate DH (complex II) has ABCD subunits. Succinate binds to subunit A just behind the ___

FAD

24

In regards to succinate DH, subunit B has three Fe-S centers, ____ is bound to subunit B, and ___ b is sandwiched between subunits C and D

ubiquinone; heme

25

In reagards to succinate DH, electrons move from succinate to FAD, then through the three Fe-S centers to ubiquinone. FAD accepts ___ electrons from succinate. Electrons pass one at a time via __-__ centers to Q, which becomes reduced QH2

2; Fe-S

26

Does succinate DH (complex II) transport protons?

no

27

In regards to complex III, ubiquinone: cytochrome c oxidoreductase, the complex has two distinct binding sites for ubiquinone, Qn and Qp, which correspond to sites of what?

sites of inhibition by two drugs that block oxidative phosphorylation

28

In regards to complex III, ubiquinone: cytochrome c oxidoreductase, Antimycin A blocks electron flow from ___ __ to ___, binds at ___

heme bh; Q; Qn

29

In regards to complex III, Myxothiazol prevents electron flow from ___ to the ___ __--__ protein, binds at ___

QH2; Rieske iron-sulfur; Qp

30

In regards to complex III, the ___ structure is essential to function. The interface between monomers forms two caverns, each containing a Qp site from one monomer and a Qn site from the other.

dimeric

31

Electron transfer through complex IV begins with cytochrome C, Two molecules of reduced cytochrome c donate an electron to the binuclear center ___

Cua

32

In regards to complex IV, after electrons are donated to Cua, they pass through heme __ to the Fe-Cu center. Delivery of two more electrons from cytochrome c converts the ___ to two molecules of water, with use of 4 substrate protons from the matrix

a; O2

note: at the same time, 4 protons are pumped from the matrix

33

In summary of the ETC, electrons reach Q through complex __ and ___. The reduced Q (___) serves as a mobile carrier of electrons an protons.

I; II; QH2

34

In summary of the ETC, electrons are passed to complex III which passes them to another mobile connecting link, ____ __. Complex IV then transfers electrons from reduced cytochrome C to ___

cytochrome C; O2

35

In summary of the ETC, Complexes I, III, and IV are accompanied by ___ flow from the matrix to the inter membrane space

proton

36

Ubiquinol diffuses freely in the membrane and is oxidized by complex ___

III

37

2 electrons from NADH to O2 result in the translocation of 10 protons across the membrane Thus, for each pair of electrons transferred to O2, there are ___ from complex I, ___ from complex II, and ___ from complex IV

4; 4; 2