Respiratory Chain

Question 1

Oxidation- reduction proteins are located within the

Answer 1

mitocondrial membrane

Question 2

This respiratory chain serves to break up the 52 kcal/mole available from the flow of ___from NADH to O2 into approximately three equal amounts.

Answer 2

2 electrons

Question 3

This respiratory chain serves to break up the 52 kcal/mole available from the flow of 2 electrons from NADH to O2

the majority of this energy is used to

Answer 3

form atp

Question 4

The rate of respiration is controlled by the availability of ___

Answer 4

ADP

Question 5

Advantages of a membrane-bound respiratory chain chain

Answer 5

(1) Kinetics: Not limited by the rate of diffusion; no mobile carrier needed.
(2) Stability of intermediates: reduced fuel will be converted to energy stored in an electrochemical gradient. For a gradient you need two compartments. The membrane provides such a boundary.

Question 6

Flavins:___donor/acceptor

Answer 6

two-electron

Question 7

Flavins have a ___ addition

Answer 7

1,4

Question 8

NADH dehydrogenase contains tightly bound

Answer 8

FMN

Question 9

Succ. Dehyd. contains covalently bound ___

Answer 9

FAD

Question 10

Iron-Sulfur Centers: Accept e-1s from

Answer 10

Flavins and Q

Question 11

iron sulfate centers may have ___ irons per
center

Answer 11

2-4

Question 12

Iron-Sulfur Centers have how many electron donor/acceptors?

Answer 12

They may have 2-4 irons per
center, but they are _one-electron donor/acceptors. _

Question 13

Acidification of iron sulfar centers leads to →

Answer 13

H2S gas

Question 14

Ubiquinone: ___-electron donor/acceptor

Answer 14

two

Question 15

ubiquinone Functions as an electron ___.

Answer 15

buffer

Question 16

Ubiquinone has ___ additon

Answer 16

1,6

Question 17

Hemes: ___-electron donor/acceptors

Answer 17

one

Question 18

The heme is covalently attached to two ____ side chains in cytochromes c and c1.

Answer 18

cysteine

Question 19

The iron atom of the heme group in cytochrome c coordinates to a

Answer 19

methionine and a histidine side chain in addition to the 4 porphyrin-ring nitrogens.

Question 20

Copper Centers: one-electron donor/acceptors in

Answer 20

cytochrome oxidase

Question 21

Copper center A contains ___ Cu

Answer 21

two

Question 22

what forms the forms the O2 binding site at the end of the Respiratory Chain?

Answer 22

1. Copper center B
2. the heme iron of Cyt a3

in cytochrome oxidase

Question 23

what is in cytosohome oxidase?

Answer 23

CuA, CuB, Cyt a, Cyt a3

Question 24

path of electron flow in cytochrome oxidase?

Answer 24

to CuA -> cytocrhome a -> cytochrome 3 -> cuB

Question 25

The participation of two copper centers and two heme irons in cytochrome oxidase may be required in order to (2)

Answer 25

1. rapidly deliver 4e- to O2
2. avoid production of H2O2 and superoxides.

Question 26

For efficient flow, components should be arranged in order of ___

Answer 26

INCREASING ELECTRON AFFINITY

Question 27

order of the components of the respiratory chain?

Answer 27

Nad -> Q -> b -> C -> a

Question 28

___ contains three catalytic sites for ATP synthesis

Answer 28

F1

Question 29

____ is a hydrophobic complex that transverses the membrane and carries protons from one site to the other.

Answer 29

Fo

Question 30

the endergonic synthesis of ATP is obligatorily coupled to the ___

Answer 30

exergonic redox reactions

the reverse is also true

Question 31

Oxidative Phosphorylation

____ → NAD+ + 3 ATP + 4 H2O

Answer 31

NADH + H+ + 1/2 O2 + 3 ADP + 3 Pi

Question 32

NADH + H+ + 1/2 O2 + 3 ADP + 3 Pi → ___

Answer 32

NAD+ + 3 ATP + 4 H2O

Question 33

______ functions as a common

intermediate linking Oxidatian on to Phosphorylation.

Answer 33

electrochemical gradient

Question 34

___ is coupled to ATP synthesis.

The rate of respiration is controlled by the availability of ADP

Answer 34

Oxygen consumption

Question 35

ADP consumed/0OCnsumped =?

Answer 35

atp formed per pair of electrons

Question 36

An explanation for respiratory control:?

Answer 36

Back pressure from the electrochemical gradient stops the flow of electrons down the respiratory chain at those points where proton transport is coupled to a redox reaction unless the protons are carried back into the matrix space

Question 37

1 electron donors/acceptors

Answer 37

1. iron sulfur center
2. hemes
3. copper centers

Question 38

2 electron donor/acceptor

Answer 38

1. flavins: fmn, fmnh2, fad
2. ubiquinone

Question 39

the e- carriers along the respiratory chain are arranged in order of increasing affinity for electron

this is important for the ____

Answer 39

efficiency of extracting useful energy.

Question 40

____ is an excess mobile e- carrier between the early dehydrogenases and the later part of the respiratory chain.

Answer 40

ubiquinone

Question 41

_____of cytochrome oxidase is the only heme group in the respiratory chain that binds O2

Answer 41

cytochrome a3

Question 42

cytochrome oxidase is able to provide rapid delivery of ___ to the terminal acceptor, O2.

Answer 42

4 e-

Question 43

how is the two part structure of the ATP synthase complex oriented on the inner mitochondrial membrane.

Answer 43

Fo is in the inside of the membrane

F1 is in the matrix

Question 44

The limitation placed on_____by the chemisosmotic gradient is termed respiratory control.

Answer 44

electron transport

Question 45

If the electrochemical gradient is destroyed by damaging the membranes, respiratory control is

Answer 45

abolished and electron transport can run freely.