ETC and oxidative phosphorylation

Question 1

What is the label given to exergonic reactions in metabolism?

Answer 1

Catabolic

Question 2

What is the label given to endergonic reactions in metabolism?

Answer 2

Anabolic

Question 3

What makes a reaction oxidative?

Answer 3

Gain of oxygen
Loss of electrons
Loss of hydrogen

Question 4

What makes a reaction reductive?

Answer 4

Loss of oxygen
Gain of electrons
Gain of hydrogen

Question 5

What are the three molecules that can move freely across the IMM?

Answer 5

H2O
O2
CO2

Question 6

What are the sources of FADH2 used in the ETC?

Answer 6

Succinate dehydrogenase in TCA cycle
Acyl CoA dehydrogenase in beta-oxidation

Question 7

What are the sources of NADH used in the ETC?

Answer 7

Glyceraldehyde 3P DH in glycolysis
PDH in glycolysis
Isocitrate DH in TCA cycle
Alpha-ketoglutarate DH in TCA cycle
Malate DH in TCA cycle
Beta-hydroxyacyl CoA DH in beta-oxidation

Question 8

What are the two shuttles to bring NADH into the mitochondria?

Answer 8

Malate-aspartate shuttle
Glycerol 3P shuttle

Question 9

In which cells of the body is the malate-aspartate shuttle found?

Answer 9

Liver
Heart muscles

Question 10

In which cells of the body is the glycerol 3P shuttle mainly used?

Answer 10

Brain
Skeletal muscle

Question 11

What are the mobile carriers used in the ETC?

Answer 11

Ubiquinone/coenzyme Q
Cytochrome C

Question 12

What are the two minerals found in the cytochromes used in ETC?

Answer 12

Iron in all
Copper in a and a3

Question 13

What are the prosthetic groups of complex I of the ETC?

Answer 13

FMN
6-7 Fe-S clusters

Question 14

What is the basic function of complex I of the ETC?

Answer 14

Change NADH to NAD giving the electrons to CoQ

Question 15

What are the prosthetic groups of complex II of the ETC?

Answer 15

FAD
Fe-S

Question 16

What is the basic function of complex II of the ETC?

Answer 16

Transfers electrons from FADH2 to CoQ

Question 17

What is the enzyme name of complex I of the ETC?

Answer 17

NADH CoQ reductase/NADH dehydrogenase

Question 18

What is the enzyme name of complex II of the ETC?

Answer 18

Succinate CoQ reductase

Question 19

What is the enzyme name of the Complex III of the ETC?

Answer 19

Cytochrome reductase

Question 20

What is the general function of complex III of the ETC?

Answer 20

Accepts electrons from CoQ and transfers them to cytochrome C

Question 21

What are the prosthetic groups of complex III?

Answer 21

Cytochrome B
Fe-S
Cytochrome C1

Question 22

What is the enzyme name of complex IV of the ETC?

Answer 22

Cytochrome oxidase

Question 23

What is the general function of complex IV of the ETC?

Answer 23

Accept electrons from cytochrome C and transfer them to O2 to make H2O

Question 24

What are the prosthetic groups of complex IV?

Answer 24

Cytochrome A with copper
Cytochrome A3 with copper

Question 25

What are the two subunits of ATP synthase on IMM?

Answer 25

Fo - proton channel F1 - catalyzes ATP synthesis

Question 26

How with increased levels of ADP, Pi, NADH, and FADH2 affect the rate of ETC?

Answer 26

They will increase the rate of ETC

Question 27

How will hypoxia affect the rate of the ETC?

Answer 27

Decrease the rate

Question 28

What are the site specific inhibitors of complex I of the ETC?

Answer 28

Amobarbital Rotenone Piericidin A

Question 29

What are the site specific inhibitors of complex II of the ETC?

Answer 29

TTFA - tenoyltrifluoro acetone Carboxin

Question 30

What are the site specific inhibitors of complex III of the ETC?

Answer 30

Antimyxin A BAL - British antilewisite

Question 31

What are the site specific inhibitors of complex IV of the ETC?

Answer 31

Cyanide Carbon monoxide Sodium azide Hydrogen sulfide

Question 32

What are inhibitors of oxidative phosphorylation?

Answer 32

Oligomycin Uncouplers Atractyloside

Question 33

What is the action of uncouplers?

Answer 33

Leakage of protons back into the mitochondrial matrix acting as ionophores

Question 34

What is the result of the action of uncouplers?

Answer 34

Abolition of the electrochemical gradient

Question 35

What are some examples of uncouplers?

Answer 35

2,4 dinitrophenol Dinitrocresol High dose of aspirin High dose of salicylates UCP in brown adipose tissue

Question 36

How does oligomycin inhibit oxidative phosphorylation?

Answer 36

Binds to Fo region of ATP synthase and closes the proton channel

Question 37

How does atractyloside inhibit oxidative phosphorylation?

Answer 37

Inhibits ATP transport across IMM