Electron transport chain

Question 1

What happens to FADH2 if it is formed cytoplasmically, outside the mitochondrial matrix?

Answer 1

It diffuses across into the mitochondria.

Question 2

What happens to NADH when it is formed cytoplasmically, outside the mitochondrial matrix?

Answer 2

It releases its electrons into the glycerol phosphate shuttle where they are picked up by FADH[2]. This method will yield slightly less ATP.

Question 3

Where does NADH release its electrons to in the ETC?

Answer 3

Complex 1.

Question 4

What do the electrons ‘hop’ between on the complex 1?

Answer 4

Fe-S and FMN centres until they reach the ‘top’ of the complex.

Question 5

When electrons reach the top of complex 1, what uptakes the electron?

Answer 5

upiquinone.

Question 6

What also happens when the electron is ‘climbing’ complex 1?

Answer 6

H+ is pumped into the intermembrane space

Question 7

What are the major differences between complex 1 and 2?

Answer 7

1) complex 2 receives electrons from FADH2

2) A haeme group funnels the electron into upiquinone

Question 8

What is the purpose of a haeme funnel?

Answer 8

To funnel the electrons into upiquinone to prevent them leaking and forming free radicals.

Question 9

What does complex 3 do to ubiquinol?

Answer 9

Removes its electron and passes it to cytochrome C