Question

Which of the following forms as a result of 19 NADH molecules entering the electron transport chain during aerobic respiration?

1. 57 ATP
2. 19 water molecules

1. Only 1
2. Only 2
3. Both 1 and 2
4. Neither 1 or 2

Answer 1

Ans- c. both 1 and 2

Explanation- When 1 NADH enters electron transport chain, electrons extracted from NADH are passed from complex I to complex IV, with the movement of these electrons, protons are pumped from mitochondrial matrix to intermembrtane space. This creates a proton gradient and proton motive force. Utilising the proton motive force, ATP is synthesised. 1 NADH forms 3 ATP, therefore, 19 NADH form 57 ATP. The electrons the transferred to molecular oxygen forming water. 19 water molecules for 19 NADH.