Q. The energy releasing metabolic process in which substrate is oxidised without an external electron acceptor is called
A) Photorespiration
B) Glycolysis
C) Fermentation
D) Aerobic respiration
Explanation
[Solution from source] In fermentation, NADH from glycolysis is reoxidised by reducing an internal organic molecule (pyruvate or acetaldehyde), so no external electron acceptor such as O₂ is needed. Aerobic respiration uses O₂ as the final external acceptor. Glycolysis is only one stage and needs NAD⁺ to be regenerated. Answer (3).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.