Question

Fermentation is a type of anaerobic respiration that occurs in yeast and bacteria. What is the function of fermentation?
i) Regenerate NAD from NADH.
ii) Produce oxygen as a waste product.
iii) Produce ATP
A) I only
B) II only
C) III only
D) I and II only
E) I and III only

Answer 1

Fermentation, the chemical process by which molecules such as glucose are broken down anaerobically. It is the process of formation of ethanol and releases some amount of energy and glucose release also. In yeast and bacteria enzymes are released and breakdown of substrates placed outside the cell. The pyruvate is formed by glycolysis and the end product is be-ethyl alcohol, carbon-dioxide and energy.

Complete answer:
A) I only – regenerate NAD and NADH. The organic molecule is the final electron acceptor to regenerate NAD to NADH so that glycolysis can continue. And fermentation does not involve electron transport chains.
Therefore, option A is the correct answer.
B) II only- production of oxygen is not waste as it is essential for the process as ATP is required.
Option B is not the correct answer.
C) III only- ATP production is the key factor in the fermentation process as the releases of gases occur.
Option C is not the correct answer.
D) I and II only- the coenzyme NAD can be used again and again and breaking of glucose also.
Option D is not the correct answer.
E) I and III only- the enzymes in process also release energy. The micro-organisms primarily produce adenosine triphosphate.
Option E is not the correct answer.

Note:
The temperature ranging from yeast fermentation is between $32 - 35^\circ$. The elevated temperature is in phases of ethanol production and is hazardous during later stages of fermentation. In food fermentation the cucumbers, kombucha and beer production.