Answer:
Explanation:
Fermentation is a kind of anaerobic process in which organic substances especially carbohydrate is changes into different substances due to the action of certain enzymes. The end product of glycolysis is pyruvate and NADH that play an important role in the process of fermentation. When oxygen is absent then the NADH molecule is used to change the pyruvate into lactic acid and thus the formation of NAD+ occurs that is used to continue the glycolysis process.