For each NADH that supplies electrons to the electron transp

For each NADH that supplies electrons to the electron transport system, ________ ATP(s) is/are synthesized. For each FADH₂ that supplies electrons to the electron transport system, ________ ATP(s) is/are synthesized.

Question options:

1)

2; 32

2)

3; 2

3)

1; 3

4)

32; 2

5)

2; 3

Solution

For each NADH that supplies electrons to the electron transport system, three ATPs are synthesized. For each FADH2 that supplies electrons to the electron transport system, two ATPs are synthesized.

Since NADH provides its electron to the complex I of electron transport system, then complex III and then complex IV of the ETS, while FADH₂ provide its electron to the complex II instead of complex I of the ETS.

Complex I have more power to pump the proton than the complex II, so NADH produce 3 ATP while FADH produce 2 ATP.