Ques. 1AIPMT 2003
In alcohol fermentation
- triose phosphate is the electron donor while acetaldehyde is the electron acceptor
- triose phosphate is the electron donor while pyruvic acid is the electron acceptor
- there is no electron donor
- oxygen is the electron acceptor.
Answer
(1) triose phosphate is the electron donor while acetaldehyde is the electron acceptor
Solution
In glycolysis, 3-phosphoglyceraldehyde (triose phosphate) is oxidised and NAD+ is reduced to NADH + H+ ⇒ triose phosphate is the electron donor.
As per NCERT, in alcoholic fermentation pyruvic acid is converted to CO2 and ethanol by pyruvic acid decarboxylase and alcohol dehydrogenase, and NADH is reoxidised to NAD+.
⇒ Pyruvic acid is first decarboxylated to acetaldehyde, and acetaldehyde accepts the electrons (hydrogen) from NADH to form ethanol.
∴ Triose phosphate is the electron donor and acetaldehyde is the electron acceptor; oxygen is not involved.
Answer: (1)