Question

Choose the correct answer from the alternatives given:
The end product of alcoholic fermentation is:
A. ethanol or lactic acid
B. acetaldehyde
C. water and CO${}_2$
D. pyruvic acid.

Answer 1

Hint: In this type of fermentation sugar is converted into cellular energy, producing ethanol and carbon dioxide as by-products.

Complete answer: Alcoholic fermentation is known as lactic acid fermentation; it is anaerobic process that does not require oxygen. It is the method of release of energy by incomplete degradation of natural food so the end products are never completely inorganic. First glycolysis happens and produces two molecules of pyruvate after that fermentation happens; no oxygen involved and later forms ethyl alcohol and lactic acid.

Now lets us find the solution from given options –
1. Alcoholic fermentation is a kind of anaerobic respiration that consists of glycolysis accompanied by means of the conversion of pyruvic acid to ethanol and carbon dioxide and the regeneration of NAD+ from NADH.
2. In alcoholic fermentation under anaerobic conditions, the pyruvate can be converted to ethanol, in which it first converts into a halfway molecule called acetaldehyde, which further releases carbon dioxide, and acetaldehyde is converted into ethanol.
3. In the alcoholic fermentation method a carboxyl group is eliminated from pyruvic acid, releasing carbon dioxide as a gas.
4. In alcoholic fermentation, the pyruvic acid from glycolysis loses one carbon in the form of carbon dioxide to produce acetaldehyde, which is decreased to ethyl alcohol by NADH.

Thus, the right answer is A i.e. ethanol or lactic acid.

Note: Alcoholic fermentation occurs due to micro-organisms including yeast and converts glucose to energy, that is released as carbon dioxide.