Question

Which metabolic pathway is common to both fermentation, a type of anaerobic respiration, and aerobic respiration?

• A. Glycolysis
• B. Krebs cycle
• C. Acetyl Co-A formed from pyruvate
• D. Electron transport chain
• E. Chemiosmosis

Answer 1

Answer: (A)

A. Glycolysis is a part of cellular respiration and is common to both aerobic and anaerobic respiration. It occurs in the cytosol of the cells. It is an enzyme controlled 10 steps reaction by which glucose, fructose or sucrose is reduced to form 3 carbon compound pyruvate with the production of ATP and NADH.

B. Krebs cycle is a catabolic reaction as it oxidizes acetyl Co-A and organic acids into CO₂ and ‎H₂O. In eukaryotes, Krebs cycle take place in the matrix of the mitochondrion whereas in prokaryotes, Krebs cycle take in the cytoplasm.

C. Electron transport chain is present in the inner membrane of mitochondrion in eukaryotes and in the cellular membrane of prokaryotes. Through ETC ATP molecules are produced by oxidative phosphorylation.

D. Acetyl Co-A is formed from the pyruvate by the action of Pyruvate Dehydrogenase Complex, also known as PDH.

E. Chemiosmosis describes the movement of ions down the electrochemical gradient across a membrane that results in ATP formation.

So, the correct answer is Glycolysis.