Question

In an anaerobic environment, the main function of alcoholic fermentation is (justify your answer a. Produce amino acids for protein synthesis b. Generate a proton gradient for the synthesis of ATP c. Oxidize glucose molecules to generate reduced electron carriers d. Generate alcohol and acetaldehyde e. Regenerate NAD from NADH so that glycolysis can continue

Answer 1

In alcohol fermentation (anaerobic process) sugars are converted into cellular energy producing ethanol and CO₂ as waste products.

In the first part, the enzyme invertase cleaves the glycosidic linkage between the molecules of glucose and fructose as shown below

C₁₂H₂₂O₁₁ + H₂O + invertase → 2 C₆H₁₂O₆

Next, each glucose molecule is broken down into two pyruvate molecules as shown below (also known as glycolysis)

C₆H₁₂O₆ + 2 ADP + 2 P_i + 2 NAD⁺ → 2 CH₃COCOO⁻ + 2 ATP + 2 NADH + 2 H₂O + 2 H⁺

In the second part known as fermentation, the two pyruvate molecules are converted into two CO₂ molecules and two molecules of ethanol. Two molecules of ATP used as cellular energy are synthesized under a proton (H⁺) gradient.

The main purpose of alcohol fermentation is to produce ATP, the energy bank for cells, under anaerobic conditions.

Option b)