Question

In mitochondria during aerobic respiration how many times oxidative decarboxylation takes place from one molecule of acetyl CoA?

• A. 1
• B. 3
• C. 2
• D. 4

Answer 1

The correct option is B 3

• During aerobic respiration, when acetyl-CoA enters the Krebs cycle inside the mitochondrial matrix, it is oxidized to CO${}_2$ while at the same time reducing NAD to NADH.
  

Kreb's cycle:

• Isocitric is oxidized by NAD+, at the same time the NAD+ is reduced from NADH. CO${}_2$ is released forming alpha-ketoglutarate.
  
• CoA oxidizes alpha-ketoglutarate to produce Succinyl CoA, NAD+ is reduced to form NADH, CO${}_2$ is released again.

So, the correct option is '3'.