Question

Aerobic respiration differs from fermentation –
A. In having vigorous oxidation of NADH to $NA{D^ + }$
B. In having a partial breakdown of glucose in the presence of ${O_2}$
C. In producing fewer ATP molecules per glucose molecule
D. In being only catabolic in nature

Answer 1

Hint:The major difference would be that aerobic respiration tends to have vigorous oxidation of NADH to $NA{D^ + }$, as they serve as the important electron acceptors in the electron transport chain to produce ATP, whereas in fermentation both $NA{D^ + }$ and NADH are recycled at different stages of the pathway and use substrate-level phosphorylation to produce ATP.

Complete answer:Respiration of any form primarily depends on producing ATP from a given food source, mainly glucose. And there are two methods of respiration, namely aerobic and anaerobic. Aerobic and anaerobic respiration is where ATP molecules are produced via oxidative phosphorylation, in the presence and or absence of oxygen.
In fermentation, the reactions occur within an anaerobic environment but metabolically fermentation and anaerobic respiration are different. In the case of anaerobic respiration, there is oxidative phosphorylation where the electron acceptors are other oxygen species such as nitrates, sulfates, etc. unlike molecular oxygen in the case of aerobic respiration.
In fermentation, there is substrate-level phosphorylation where ATP molecules are synthesized by means of gaining phosphate molecules from other phosphorylated substrates. Here $NA{D^ + }$ and NADH are recycled at each stage and there is no vigorous oxidation of NADH to $NA{D^ + }$, as seen mainly in aerobic respiration.
In the case of aerobic respiration, as oxidative phosphorylation occurs, with molecular oxygen as the electron acceptor there is the rapid oxidation of NADH to $NA{D^ + }$ during the electron transport chain, therefore producing the most number of ATP molecules, then compared to anaerobic respiration and fermentation.

Therefore, the correct answer is option A.

Note:Aerobic and anaerobic respiration obtain ATP by means of oxidative phosphorylation
Aerobic respiration uses molecular oxygen as the electron acceptor thus has faster oxidation of NADH to $NA{D^ + }$ and yields more ATPs
Anaerobic respiration uses other oxygen species than molecular oxygen as the electron acceptor and thus only produces a lesser amount of ATPs
Fermentation employs substrate-level phosphorylation to obtain ATP, where an ADP molecule, receives a phosphate molecule from other chemical substrates.
The NADH and $NA{D^ + }$ are recycled throughout the process of fermentation and thus there is a slow yet cyclic oxidation and reduction of these two compounds.