shuttle pathways

Question 1

Inner mitochondrial membrane is impermeable to ??? and ??? and must use a shuttle to regenerate NAD+ for glycolysis; solution is to shuttle electrons across membrane, rather than NADH itself

Answer 1

NADH and NAD+

Question 2

Most of the NADH used in electron
transport is produced in the???

Answer 2

mitochondrial matrix

Question 3

NADH formed in the ??? of cells
needs to ??? into NAD+ to keep ??? going.

Answer 3

cytosol;
reoxidized;
glycolysis

Question 4

Under anaerobic conditions, ??? is regenerated by

Answer 4

NAD+;
lactate dehydrogenase

Question 5

Under aerobic conditions, the electrons of NADH need to be shuttled into the ???

Answer 5

matrix of the mitochondria

Question 6

shuttle pathways (3)

Answer 6

glycerophosphate shuttle
malate-aspartate shuttle
ATP-ADP Transport

Question 7

GLYCEROPHOSPHATE SHUTTLE:

NADH can’t enter mitochondria, so through ???, the H is transferred to DHAP

Answer 7

hydrolysis

Question 8

GLYCEROPHOSPHATE SHUTTLE:

In the first step, ??? produced in the cytosol transfers its electrons to
??? to form ???

Answer 8

NADH;
dihydroxyacetone phosphate;
glycerol-3-phosphate

Question 9

GLYCEROPHOSPHATE SHUTTLE:

Gycerol-3-phosphate enters the
??? space through a ???.

Glycerol-3-phosphate is then ??? into dihydroxyacetone phosphate by an ??? dependent mitochondrial membrane glycerol 3-phosphate dehydrogenase.

Answer 9

intermitochondrial;
porin;

reoxidized;
FAD;

Question 10

GLYCEROPHOSPHATE SHUTTLE:

In this shuttle the electrons of NADH are transferred to ??? to form ???

Answer 10

FAD;
FADH2

Question 11

GLYCEROPHOSPHATE SHUTTLE:

The two electrons bound by the FADH2 are transferred directly to ??? forming ???, which carries the electrons to ???

Answer 11

coenzyme Q;
QH2;
complex III

Question 12

GLYCEROPHOSPHATE SHUTTLE:

The result of this shuttle is

Answer 12

1.5 ATP/NADH

Question 13

GLYCEROPHOSPHATE SHUTTLE:

Note that this shuttle is essentially
???

Answer 13

irreversible

Question 14

THE MALATE-ASPARTATE SHUTTLE:

In the cytosol, ??? is reduced to malate by ??? which uses ??? as the reductant.

Answer 14

oxaloacetate;
malate dehydrogenase;
NADH

Question 15

THE MALATE-ASPARTATE SHUTTLE:

Malate is transported across the inner mitochondrial membrane by the ??? or ??? carrier

Answer 15

dicarboxylic acid or tricarboxylic acid carrier.

Question 16

THE MALATE-ASPARTATE SHUTTLE:

The matrix, the malate is reoxidized by ??? to generate ??? and ??? which can now transfer its electrons to ???

Answer 16

malate dehydrogenase;
oxaloacetate and NADH;
Complex I

Question 17

THE MALATE-ASPARTATE SHUTTLE:

The oxaloacetate is transaminated by ??? to form ???

Answer 17

glutamine;
aspartate and α-ketoglutarate

Question 18

THE MALATE-ASPARTATE SHUTTLE:

Aspartate can be transported across the inner mitochondrial membrane by the ???

In the cytosol aspartate transaminates ??? to reform ???completing the cycle.

Answer 18

dicarboxylic acid carrier;
α-ketoglutarate;
oxaloacetate

Question 19

which yields more energy?

glycerophosphate or malate-aspartate shuttle?

Answer 19

malate-aspartate shuttle?

since NADH has more energy content than FADH

Question 20

malate-aspartate shuttle generates ??? and is completely

Answer 20

2.5 ATP/NADH;
reversible

Question 21

malate-aspartate shuttle:

glutamate transfer ??? to oxaloacetate, forming ??? which can pass through

Answer 21

amino group;
aspartate

Question 22

glutamate to a-ketoglutarate

Answer 22

de-amination

Question 23

oxaloacetate to aspartate (from glutamate)

Answer 23

amination

Question 24

The inner mitochondrial membrane requires specialized carriers to transport ADP and Pi from the cytosol (where ATP is used and converted to ADP in many energy –requiring reactions.

Answer 24

ATP-ADP Transport

Question 25

ATP-ADP Transport: An ??? transports one molecule of ??? from the ??? into the mitochondria, while exporting one ??? from the ??? back into the cytosol.

Answer 25

adenine nucleotide carrier; ADP; cytosol; ATP; matrix

Question 26

ATP-ADP Transport: The carrier is strongly inhibited by the plant toxin ??? resulting in depletion of ??? and cessation of ???

Answer 26

ATRACTYLOSIDE; mitochondrial ADP pool; ATP production

Question 27

These compounds prevent the passage of electrons by binding to a compound of the chain, blocking the oxidation reaction.

Answer 27

inhibitors

Question 28

Because electron transport and oxidative phosphorylation are tightly ??? site specific inhibition of the electron transport chain also inhibits ???

Answer 28

coupled; ATP synthesis

Question 29

is a common insecticide that strongly inhibits the electron transport of complex I.

Answer 29

Rotenone

Question 30

is a natural product obtained from the roots of several species of plants.

Answer 30

Rotenone

Question 31

Tribes in certain parts of the world beat the roots of trees along riverbanks to release ??? into the water which paralyzes fish and makes them easy prey.

Answer 31

rotenone

Question 32

is a barbiturate that inhibits the electron transport of complex I.

Answer 32

Amytal

Question 33

is painkiller that also inhibits complex I.

Answer 33

Demerol

Question 34

??? and ??? specifically block electron transport in Complex II.

Answer 34

2-Thenoyltrifluoroacetone and carboxin

Question 35

is an antibiotic that inhibits electron transfer in complex III by blocking the transfer of electrons between Cyt bH and coenzyme Q bound at the QN site.

Answer 35

Antimycin A1

Question 36

antimycin attacks what apparatus?

Answer 36

respiratory apparatus - (mitochondria)

Question 37

where energy is manufactured

Answer 37

respiratory apparatus

Question 38

(3) all inhibit electron transfer in Complex V by binding tightly with the iron coordinated in Cyt a3. ??? and ??? bind to the iron when the iron is in the ferric state.

Answer 38

Cyanide, azide and carbon monoxide; Azide and cyanide

Question 39

Carbon monoxide is toxic due to its affinity for the ??? of ???

Answer 39

heme iron; hemoglobin

Question 40

Animals have relatively few molecules of ???. Consequently an exposure to a small quantity of azide or cyanide can ??? The toxicity of cyanide is solely from its ability to ???

Answer 40

Cyt a3; be lethal; arrest electron transport

Question 41

forms covalent bonds to a-glutamate residue of the c subunit of F0 When this is covalently attached it blocks the ???, which causes the rotation and ATP synthesis to ???

Answer 41

DCCD (Diclyclohexylcarbodiimide); proton channel; cease

Question 42

binds directly to ATP synthase F0 subunit and blocks the flow of protons through the channel

Answer 42

Oligomycin

Question 43

Electron transport and oxidative phosphorylation can be uncoupled by compounds that increase the permeability of the inner mitochondrial membrane

Answer 43

uncouples

Question 44

The ??? of oxidative phosphorylation from electron transport generates heat.

Answer 44

uncoupling

Question 45

Hibernating animals and newborn animals (including human beings) contain ??? The adipose tissue is brown due to the high ???? of the tissue.

Answer 45

brown adipose tissue; mitochondria content

Question 46

An endogenous protein called ??? uncouples ATP synthesis from electron transport by opening up a passive proton channel (UCP-1) through the inner mitochondrial membrane. The collapse of the pH gradient generate ???

Answer 46

thermogenin; heat

Question 47

– A lipophilic proton carrier that readily diffuses through the mitochondrial membrane.

Answer 47

2,4 dinitrophenol

Question 48

This uncoupler causes electron transport to proceed at a rapid rate without establishing a proton gradient

Answer 48

2,4 dinitrophenol

Question 49

The energy produced by the transport of electron is released as ??? rather than being used to ???

Answer 49

heat; synthesize ATP

Question 50

At high doses this drug uncouple OP. This explains the fever that accompanies toxic overdoses of these drugs

Answer 50

Aspirin

Question 51

too much CO2 is bad why?

Answer 51

it is preferred by hemoglobin, so oxygen will be ignored and will bind to CO2 instead, results in lack of O2 (ded)