Correct option is B
The correct answer is (b) 3 NADH + 1 FADH₂ + 1 GTP
Explanation:
For each molecule of acetyl-CoA that enters the citric acid cycle (also known as the Krebs cycle), the following molecules are produced:
3 NADH:
During the citric acid cycle, 3 NADH molecules are produced through the following reactions:Conversion of isocitrate to α-ketoglutarate (NAD+ is reduced to NADH)
Conversion of α-ketoglutarate to succinyl-CoA (NAD+ is reduced to NADH)
Conversion of malate to oxaloacetate (NAD+ is reduced to NADH)
1 FADH₂:
1 FADH₂ is produced when succinate is converted to fumarate, where FAD is reduced to FADH₂.1 GTP (or ATP):
1 GTP is generated via substrate-level phosphorylation during the conversion of succinyl-CoA to succinate. This GTP can later be converted into ATP.
Thus, from one molecule of acetyl-CoA, the citric acid cycle produces:
3 NADH
1 FADH₂
1 GTP
Information Booster:
NADH: NADH is an important electron carrier that transports electrons to the electron transport chain, which is used to generate ATP through oxidative phosphorylation.
FADH₂: Like NADH, FADH₂ also carries electrons to the electron transport chain but at a lower energy level than NADH, which results in slightly less ATP generation per molecule of FADH₂.
GTP: GTP (guanosine triphosphate) is produced by substrate-level phosphorylation. This GTP can be readily converted to ATP, which provides energy for cellular functions.
Additional Information:
(a) 2 NADH + 2 FADH₂ + 1 GTP
This option is incorrect because the citric acid cycle produces 3 NADH, not 2, from one molecule of acetyl-CoA. The amount of FADH₂ produced is also only 1.
(c) 3 NADH + 1 GTP
This option is incomplete because it omits the 1 FADH₂ that is produced in the citric acid cycle.
(d) 4 NADH + 1 FADH₂ + 1 GTP
This option is incorrect because the citric acid cycle only produces 3 NADH from one acetyl-CoA, not 4.
