Question

Which of the following statements is accurate concerning glucose metabolism?

A. Pyruvic acid, the product of glycolysis, is the starting block for both the Krebs cycle and fermentation.
B. Glucose is split in glycolysis and produces large amounts of ATP.
C. The electron transport chain is the final step for both fermentation and aerobic respiration.
D. Fermentation produces large amounts of ATP.

Answer 1

Answer: A. Pyruvic acid, the product of glycolysis, is the starting block for both the Krebs cycle and fermentation.

Explanation: Glycolysis is a metabolic pathway that oxidize glucose producing pyruvic acid and few ATP molecules. If the cellular microenvironment is aerobic, pyruvic acid is converted in Acetyl coA and enters into Krebs cycle and later into electron transport chain, which produce large amounts of ATP. If the cellular microenvironment is anaerobic, fermentation occurs and pyruvic acid is converted in lactic acid, ethanol, etc, producing only few ATP.