Oxidative phosphorylation

Question 1

What molecule is formed from digestion of of all the macromolecules we eat, that can then enter the TCA cycle?

Answer 1

Acetyl-CoA

Question 2

Where does oxidative phosphorylation takes place?

Answer 2

Inner mitochondrial membrane

Question 3

What are the 2 mobile electron carriers of the electron transport chain?

Answer 3

Coenzyme Q
Cytochrome C

Question 4

What is another name for coenzyme Q?

Answer 4

Ubiquinone

Question 5

What is the ultimate e+ acceptor that drives the electron transport chain?

Answer 5

O2

Question 6

ATP synthase refers to which complex?

Answer 6

Complex V

Question 7

Complex I is known as

Answer 7

NADH-Q-oxidoreductase

Question 8

Complexe I receives e- from what high energy molecule?

Answer 8

NADH

Question 9

Complex II receives e- from what high energy molecule?

Answer 9

FADH2

From the conversion of succinate to fumarate

Question 10

What is the name of complex II ?

Answer 10

Succinate-Q-reductase

Question 11

Electrons are transferred from NADH to coenzyme Q via what what complex?

Answer 11

Complex I

Question 12

Cyt C oxidase refers to what complex ?

Answer 12

Complex IV

Question 13

Which complex passes the e- to cytochrome C

Answer 13

Complex III

Q-cytC oxidoreductase

Question 14

Which complex completes the the electron transport chain, passing the e- to O2 cause it to be reduced to H20?

Answer 14

Complex IV

Cyt C oxidase

Question 15

What are the 2 sources of NADH?

Answer 15

Glycolysis
TCA cycle

Question 16

Which complexes have flavin as a coenzyme?

Answer 16

Complex I & II in form of FMN and FAD (vit B2)

Question 17

Which complex is not involved in pumping of protons ?

Answer 17

Complex II

Question 18

Which complex is also known as Cytochrome a + a3

Answer 18

Complex IV

Question 19

Which complex is also known as Cytochrome bc 1 ?

Answer 19

Complex III

Question 20

Which electron transport chain carrier is a lipid ?

Answer 20

Coenzyme Q

Question 21

Iron-sulfur proteins are found in what complexes ?

Answer 21

I, II & III

Question 22

Which complex has 2 hemes, 2 copper centers required for splitting of molecular O2 and the only electron carrier in which the heme iron has an available site that reacts directly with O2 ?

Answer 22

Complex IV

Question 23

Which complex has iron in its free form?

Answer 23

Complex IV

Question 24

What makes the whole e- transport chain energy favorable ?

Answer 24

NADH is a strong donor and O2 is a strong acceptor.

O2 is very electronegative.

Question 25

Coenzyme Q can accept hydrogen atoms from what ?

Answer 25

Complex I Complex II Glycerophosphate dehydrogenase (glycolysis) Acyl coa dehydrogenase

Question 26

What are the 2 parts of ATP synthase

Answer 26

F0 F1 | F0 is attached to the inner mitochondrial membrane

Question 27

What sub-units of the F1 sub-unit of ATP synthase attaches ADP + Pi

Answer 27

3 b sub-units

Question 28

For each H+ pumped, how many ATPs are made

Answer 28

3

Question 29

ATP is released by which sub-unit ?

Answer 29

alpha

Question 30

Where is F1 located ?

Answer 30

In the matrix

Question 31

ATP/ADP antiporter helps with what ?

Answer 31

ADP to go in and ATP to go out as it is formed since the inner mitochondrial membrane is impermeable.

Question 32

Regulation of the electron transport chain by : | * the rate of respiration of the mitochondria

Answer 32

Availability of ADP

Question 33

For each mol of substrate oxidized by complex I, III and IV via NADH, how many mol of ATP is formed

Answer 33

2.5 ATP rounded to 3 ATP

Question 34

FAD generally enters via complex? then distributed to ?

Answer 34

complex II distributed to 3 and 4

Question 35

How many mol of ATP for 1 mol of FAD?

Answer 35

1.5 rounded up to 2

Question 36

What are uncouplers?

Answer 36

They increase the permeability of the membrane to ions or create a channel, allowing H+ to pass through the membrane without using ATP synthase. | They dirsupt the proton gradient, therefore no ATP is being made.

Question 37

What is the result of uncouplers or how to ID uncouplers in the questions?

Answer 37

No longer capture in the form ATP so the entire energy is dissipated as heat.

Question 38

Name a physiological uncoupler found in brown adipose tissue to generate heat in newborns.

Answer 38

Thermogenin | Generates heat by non shivering thermogenesis. ## Footnote Neonates have high surface body area compared to adult meaning they lose more heat.

Question 39

Example of synthetic uncouplers

Answer 39

2,4 dinitrophenol | Lipophilic amphipatic proton carrier ## Footnote Both case, physiological and synthetic uncouplers generate heat by highjacking the electron transport chain.

Question 40

Aspirin in an example of uncoupler that in high dose would lead to what ? | (and all other salicyclates)

Answer 40

Hyperthermia

Question 41

What are the 2 mechanisms that would decrease the proton gradient ?

Answer 41

Uncoupling agents Electron transport inh.

Question 42

ATP synthase inhibitors result in increase or decrease of protein gradient ?

Answer 42

Increase

Question 43

What atb binds the Fo component domain of ATP synthase, closing the H + channel and preveninting reentry of protons into the mitochondrial matrix ?

Answer 43

Oligomycin (macrolide atb) ## Footnote No heat involved here, the electron transport chain is just entirely stoped.

Question 44

Oligomycin binds which complex?

Answer 44

Complex V

Question 45

Do uncouplers bind complexes ?

Answer 45

No, they only increase permeabiliy of the membrane which disrupts the electron transport chain.

Question 46

What poisons binds complexe IV

Answer 46

Cyanid Carbon monoxide H2S Azide

Question 47

Barbiturates (amytal) binds what complex ?

Answer 47

Complex I

Question 48

Fish poison, also known as Rotenone binds which complex ?

Answer 48

Complex I

Question 49

Complex II is bound by what compound?

Answer 49

Malonate

Question 50

Metformin binds what complex ?

Answer 50

Complex I

Question 51

Antimycin A & Dimercaprol bind what complex ?

Answer 51

Complex III

Question 52

Fire is indication of what type of poisoning

Answer 52

CO Cyanide

Question 53

Cyanide binds what form of iron?

Answer 53

Fe3+

Question 54

CO binds what form of iron ?

Answer 54

Fe2+

Question 55

Presence of smoke, soot in the mouth and nose after smoke inhalation, or odor of bitter almonds would indicate what ?

Answer 55

Cyanide or CO poisoning but presence of bitter almonds would indicate cyanide poisoning.

Question 56

With is the antidote for cyanide poisoning ?

Answer 56

Hydroxocobalamin or nitrates | this rx combines with cyanide to fomr B12 which is renally cleared. ## Footnote Also Nitrites Thiosulfate

Question 57

Power outages, exhaust issues or fires, headache and no odor on pt, cherry pink color, multiple members of same household indicate?

Answer 57

CO poisoning

Question 58

What does Atractyloside ?

Answer 58

Inhibits oxidative phospo by inh transport ADP into and ATP out of the mitochondria.

Question 59

Severe diminution or absence of most oxidoreductases in the respiratory chain due to deletions or duplications of the mitochondrial DNA results in ?

Answer 59

Fatal infantile mitochondrial myopathy and renal dysfunction.

Question 60

What is Leigh syndrome ?

Answer 60

A rare neurologic disorder caused by genetic defect in oxidative phosphorylation (defective membrane protein complexes in the electron transport chain).

Question 61

What is MELAS | (Mitochondrial encephalopathy, lactic acidosis and stroke syndrome)

Answer 61

Inherited condition due to NADH-Q oxidoreductase (complex I) or cytochrome oxidase (IV) deficiency. | Caused by mutation in the mitochondrial DNA