Question

How many ATP molecules will be produced in a brain cell (neuron) from a glucose molecule involving electron transport chain only?

• A. 32
• B. 16
• C. 38
• D. 34

Answer 1

The correct option is A 32

• Glucose is first oxidised into two pyruvate molecules by glycolysis.
• The two pyruvate molecules are converted into acetyl CoA.
• Each acetyl CoA enters TCA cycle and NADH and FADH${}_2$ are produced along with ATP.
• NADH and FADH2 are also oxidised into ATP.
• When NADH is oxidised 2.5 ATP molecules are produced and when FADH${}_2$ is oxidised 1.5 ATP molecules are obtained.
• As, Glycolysis Pay off Phase produces 2 NADH (3 ATP), Substrate level phosphorylation (4 ATP), Oxidative decarboxylation of Pyruvate gives 2NADH (5 ATP) and Krebs Cycle, 6 NADH (15ATP), 2FADH${}_2$ (3 ATP), 2ATP are produced; the grand total ATP molecules formed in this way are about 30 - 32.

So, the correct answer is '32'.