Question

In the absence of NAD⁺, what happens to glycolysis?

Answer 1

Glycolysis:

1. Glycolysis is the metabolic process of the breakdown of glucose, thereby releasing energy and pyruvic acid.
2. Nicotinamide adenine dinucleotide (NAD⁺) is an important molecule in glycolysis.
3. It is a cofactor which regulates metabolism through its electron transport function in the redox reaction in glycolysis and the TCA cycle,
4. In glycolysis, NAD⁺ reduces forming NADH and H⁺. If NAD⁺ is absent, glycolysis cannot continue.
5. In glycolysis when respiration occurs in the presence of oxygen, the formed NADH is oxidized reforming NAD⁺ which can be used again in glycolysis.
6. In the absence of oxygen, pyruvate will experience fermentation. Fermentation being anaerobic, does not require oxygen and thus refills NAD⁺ from the NADH + H⁺ which is produced in glycolysis.