ETC

Question 1

Inhibitors of Complex 1.

Answer 1

Rotenone
Amytal
MPP+
Piericidin

Question 2

How is Complex 1 inhibited?

Answer 2

Inhibitors binds to ubiquinone-binding site, blocking electron transfer and prevents NADH from being oxidized.

Question 3

Inhibitors of Complex 2.

Answer 3

Malonate
Thenoyltrifluoroacetone(TTFA)
Carboxin

Question 4

How does Malonate inhibit Complex 2?

Answer 4

It is a competitive inhibitor for the active site of succinate dehydrogenase, which converts succinate to fumarate and reduces FAD in the process.

Question 5

Antimycin A is a potent ETC inhitor of what complex?

Answer 5

Complex 3.

Question 6

Which substance (s) binds to the Qo site of Complex 3, thereby preventing cytochrome c from binding?

Answer 6

Myxothiazol and Stigmatellin

Question 7

Cyanide, Azide and CO are inhibitors of which complex in the ETC?

Answer 7

Complex 4.

Question 8

How does affect the ETC?

Answer 8

Binds tightly to the oxidized iron(Fe3+) in the heme at the Copper B ion center of cytochrome c oxidase.

Question 9

How does CO affects the ETC?

Answer 9

Binds tightly to iron, in reduced form (Fe2+) present in the heme A3 of cytochrome c oxidase.

Question 10

What happens to the ETC when the active site of cytochrome c oxidase is blocked?

Answer 10

It halts the entire ETC.