Question

Which of the biochemical pathways produce ATP, NADH, and FADH${}_2$ from pyruvate?

• A. Krebs cycle
• B. Electron transport chain
• C. Fermentation
• D. Glycolysis
• E. Calvin cycle

Answer 1

The correct option is A Krebs cycle

Glycolysis is the first step of cellular respiration that breaks down glucose into two molecules of pyruvic acid. The pyruvic acid enters Kreb cycle in form of acetyl-CoA where it is oxidatively decarboxylated with the production of NADH and $FAD{H}_2$. Substrate level phosphorylation also produces 2 ATPs during Kreb cycle. Fermentation of pyruvic acid does not produce $FAD{H}_2$. Calvin cycle refers to dark reactions of photosynthesis. Electron transport chain produces NAD, FAD by oxidation of NADH and $FAD{H}_2$. Thus, the correct answer is A.