Why 3 ATP are produced from one NADH but only 2 ATP from one FADH 2?

Answer 1

So for a real answer...

The electron transport chain basically pumps out protons across the mitochondrial membrane from the matrix into the inter-membrane space, building a proton gradient. When these protons try to flow back in, they run through the ATPase and generate ATP. We can visualize this process as a chain, where electrons move through components of the chain and eject protons as they go from structure to structure.

We generally think of the beginning of this chain as the place where NADH is oxidized and gives up its electrons. However, FADH2 enters from an area which can be thought of as further down the chain. So if we think of the electron transport chain as having three steps, with each step generating one ATP, then NADH starts at step one, but FADH enters the chain later at step two. So FADH will only eject enough protons for two ATP, while NADH ejects enough for three.

That's a simple way of looking at it, at least.

Answer 2

When NADH releases the electron at the electron transport chain, it starts from complex I, which allows more ATP molecules to be produced as electron goes through. On the contrary, the FADH molecule releases their electron at the complex II, or "Q".
This results in less ATP molecules to be produced.

Answer 3

This is due to the location of NADH and FADH2 in the electron transport chain. NADH delivers electrons at complex I, while FADH2 delivers electrons at complex II. The electrons from NADH enter the chain at a higher energy level, allowing for the generation of 3 ATP through oxidative phosphorylation, compared to 2 ATP when FADH2 is the electron donor.

Answer 4

1 molecule of NADH2 has enough energy to promote 3 molecules of ATP

Answer 5

it's 2 and 3

Answer 6

2

Answer 7

3Molecules of ATP