Question

Which of the following statements is not true about fermentation?

• A. This occurs in the absence of oxygen
• B. This generally occurs in yeast
• C. In this process pyruvate or pyruvic acid changes into CO\(_2\) and ethanol
• D. This process completes in mitochondria

Hint:

Fermentation occurs in the cytoplasm, and it does not require oxygen, unlike aerobic respiration that takes place in mitochondria.

Answer 1

The Correct Option is D

Fermentation is an anaerobic process in which glucose is converted into cellular energy and byproducts, such as ethanol or lactic acid, in the absence of oxygen.
Step 1: Statement A - This occurs in the absence of oxygen.
This is true. Fermentation is an anaerobic process, meaning it occurs in the absence of oxygen. Oxygen is not required for fermentation to take place.
Step 2: Statement B - This generally occurs in yeast.
This is also true. Yeast cells are commonly used in fermentation processes, particularly in the production of ethanol (alcoholic fermentation), where glucose is converted into ethanol and carbon dioxide.
Step 3: Statement C - In this process pyruvate or pyruvic acid changes into CO\(_2\) and ethanol.
This is true. In alcoholic fermentation, pyruvate is converted into ethanol and carbon dioxide. This occurs in yeast cells and certain bacteria under anaerobic conditions.
Step 4: Statement D - This process completes in mitochondria.
This is incorrect. Fermentation occurs in the cytoplasm, not the mitochondria. The mitochondria are involved in aerobic respiration, where oxygen is used, but fermentation is an anaerobic process that takes place in the absence of oxygen.
Step 5: Conclusion.
Therefore, the statement that is not true about fermentation is (D). The process does not complete in mitochondria. The correct answer is (D).