Question

Fermentation is a process where

• A. Glucose is converted into pyruvate in the presence of oxygen
• B. Glucose is converted into pyruvate in the absence of oxygen
• C. Glucose is converted into lactate and / or alcohol in the absence of oxygen
• D. Glucose is converted into lactate and / or alcohol in the presence of oxygen

Hint:

• Fermentation is an anaerobic process (no oxygen required).
• It starts with glycolysis (glucose \(\rightarrow\) pyruvate).
• The main purpose of the steps after glycolysis in fermentation is to regenerate NAD\(^+\) so glycolysis can continue.
• Common end products: Lactic acid (lactic acid fermentation), Ethanol and CO\(_2\) (alcoholic fermentation).

Answer 1

The Correct Option is C

Fermentation Process: Fermentation is a metabolic process in which glucose is converted into substances like lactate and alcohol. This process occurs in the absence of oxygen, which categorizes it as an anaerobic process. The absence of oxygen leads to incomplete oxidation of glucose, and as a result, it does not proceed to the aerobic pathway that involves pyruvate conversion via the tricarboxylic acid cycle.

Fermentation can produce different end products depending on the type of organism and enzymes involved:

• Lactic Acid Fermentation: Common in muscle cells and some bacteria, glucose breaks down into lactic acid. The chemical equation is: C₆H₁₂O₆ → 2 CH₃CH(OH)COOH.
• Alcohol Fermentation: Occurs in yeast and some types of bacteria, transforming glucose into alcohol (ethanol) and carbon dioxide. The chemical equation is: C₆H₁₂O₆ → 2 C₂H₅OH + 2 CO₂.

Therefore, the correct description of fermentation is: Glucose is converted into lactate and/or alcohol in the absence of oxygen.