Oxidative Phosphorylation: P/O Ratio

Question 1

What is required for the proton gradient to be discharged?

Answer 1

ATP synthesis requiring an intact mitochondria

Question 2

What is required for ATP synthesis?

Answer 2

Discharge of the proton gradient (they are tightly coupled)

Question 3

How is the proton gradient established?

Answer 3

Via electron transport

Question 4

What is the term for the amount of ATP synthesized relative to O2 (substrate) reduced?

Answer 4

P/O ratio (P=product, O=O2)

Question 5

How many ATP are generated by 1 molecule of glucose?

Answer 5

32

Question 6

How many ATP come from one molecule of NADH?

Answer 6

2.5

Question 7

How many ATP come from the electrons of one molecule of FADH2?

Answer 7

1.5

Question 8

How many protons does the flow of 2 electrons through electron transport generate in the inner mitochondrial space?

Answer 8

10

Question 9

True or false: the 10 protons generated by 2 electrons from electron transport create 3 ATP, enough energy to drive 1 complete rotation of the alpha3beta3 subunit.

Answer 9

True

Question 10

How many protons are carried across the membrane when FADH2 is processed by electron transport? Why?

Answer 10

6; FADH2 enters at Complex II, allowing it to bypass Complex I and not transfer those 4 electrons

Question 11

What are the P/O ratios for ATP generated by the electrons of on FADH2 and NADH2, respectively?

Answer 11

1.5 (FADH2) and 2.5 (NADH2)