Electron Transport Chain

Question 1

what is the purpose of the ETC?

Answer 1

to finish the energy provision process by reoxidizing the cofactors produced by the TCA cycle

Question 2

where does the ETC reside?

Answer 2

in the inner membrane of the mitochondira

Question 3

where is ATP released into by the ETC?

Answer 3

into the mitochondrial matrix

Question 4

another name for the ETC is?

Answer 4

respiration chain

Question 5

The ETC is a stepwise process by which e- are carried from the ____ _____ to __

Answer 5

reduced cofactors to O2

Question 6

the cofactors that are reduced in the electron transport chain are ____ by ___

Answer 6

oxidized by oxygen

Question 7

what is the name of Complex I?

Answer 7

NADH dehydrogenase, NADH-CoQ-reductase

Question 8

what is the name of complex II?

Answer 8

succinate degydrogenase, succinate CoQ-reductase

Question 9

another name for Co-enzyme Q is?

Answer 9

ubiquinone

Question 10

what is the name of complex III?

Answer 10

cytochrome b-c1 complex, ubiquinone cytochrome c reductase

Question 11

what is the name of complex IV?

Answer 11

cytocrhome oxidase, cytochrome c oxidase

Question 12

which three complexes to NADH/H+ go through?

Answer 12

I, III and IV

Question 13

which three complexes to FADH2 go through?

Answer 13

II,III, and IV

Question 14

another name for iron complexes?

Answer 14

cytochromes

Question 15

what is the shuttle between complex I and III or complex II and III

Answer 15

CoQ (ubiquinone)

Question 16

what is the shuttle between complex III and IV?

Answer 16

Cytochrome c

Question 17

Why are only 2 moles of H+ channeled out at complex IV (as opposed to 4 at complexes I and III)?

Answer 17

The other two are used to generate one Mol of Water!

Question 18

what is responsible for the different modifications of Fe2+/Fe3+ redox potentials?

Answer 18

the different biochemical environments

Question 19

what is the only ETC carrier that is not a protein-bound cofactor?

Answer 19

ubiquinone

Question 20

where in the body is a high concentration of ubiquinone found?

Answer 20

in the heart muscles

Question 21

ubiquinone transports ___ through the ___ ____ into the ____ ___ of the mitochondira

Answer 21

it transports ptrotons through the inner membrane into the intermembrane space

Question 22

which complex is the only component of the ETC that has a copper complex?

Answer 22

complex IV (cytochrome c oxidase)

Question 23

which complex contains the binding cite for O2?

Answer 23

complex IV (cytochrome c oxidase)

Question 24

the reduction of cytochrome by complex IV(cytochrome c oxidase) is coupled to what?

Answer 24

proton transport

Question 25

the proton concentration inside complex IV is decreased by what two processes?

Answer 25

1- formation of water 2- outflux of protons by the complex

Question 26

how many protons are transported into complex IV along with the the reduction of O2?

Answer 26

4 protons

Question 27

the interaction between what two things reduce oxygen to water in complex IV?

Answer 27

the Fe and Cu complexes

Question 28

heme, by definition if a cofactor containing what?

Answer 28

Fe2+

Question 29

which complex is the only one that doesn't involve the influx of protons that is then followed by their outflux?

Answer 29

complex II

Question 30

since oxidation is always coupled with reduction, when the ___ ____ are oxidized then ___ is reduced

Answer 30

co-factors are oxidized, oxygen is reduced

Question 31

what process it redox in the TCA paired with?

Answer 31

the phosphorylation of ADP to ATP

Question 32

where does the energy used for ATP synthesis come from in the TCA cycle?

Answer 32

and proton-gradient across the inner mitochondrial membrane

Question 33

can protons pass through the inner mitochondrial membrane?

Answer 33

no, the proton gradients is made by the ETC

Question 34

the out-transport of protons by the ETC causes two kinds of gradients, what are they?

Answer 34

chemical (pH) and electrochemical (V)

Question 35

The idea that energy for ATP synthesis arises from an H+-gradient across the inner mitochondrial membrane is known as what?

Answer 35

chemiosmotic theory

Question 36

ATP synthase is made up of what tow main components?

Answer 36

a proton channel (F0) and an ATPase site (F1)

Question 37

mitochondrial F1(ATPase) particles are required for __ ____ but not for ___ ___

Answer 37

ATP synthesis, proton transport

Question 38

what subunit of the F1 (ATPase) unit rotates?

Answer 38

the gamma unit

Question 39

when the gamma unit of the F1(ATPase) unit rotates it changes the shape of what?

Answer 39

the beta subunits

Question 40

when the beta subunits are open in the F1 unit what happens?

Answer 40

ATP leaves and new ADP and Pi come in

Question 41

what happens when the beta subunits in the F1 units are lose?

Answer 41

ADP and Pi bind together

Question 42

what happens when the beta subunits in the F1 units are tight?

Answer 42

ADP and Pi react and form ATP

Question 43

give an example of an uncoupler

Answer 43

DNP (dinitrophenol)

Question 44

what do uncouplers, like DNP, do?

Answer 44

uncouple the ETC and ATP-synthases

Question 45

what protein is located in the mitochondrial membrane of adipose cells and acts as a heat generator?

Answer 45

thermogenin

Question 46

how many subunits for the ETC does mitochondrial DNA code for?

Answer 46

7

Question 47

what are the 7 subunits that mitochondrial DNA encode for in the TCA?

Answer 47

1-complex I, 1- complex III, 3 - complex IV, and 2 for ATP-synthase

Question 48

how many subunits are coded by nuclear DNA?

Answer 48

>70

Question 49

what is OXPHOS?

Answer 49

a genetic disease affecting oxidative phosphyrlation

Question 50

what is a common cause of OXPHOS?

Answer 50

mutations of mitochondrial DNA, since the mitochondria doesn't have repair systems as sophisticated as the nuclear DNA

Question 51

where is creatine phosphate mostly found?

Answer 51

the brain, muscle and especially heart cells

Question 52

what does creatine phosphate do?

Answer 52

acts as a buffer for ATP, by providing fast ATP generation via substrate level phosphorylation