Question

A low level of carbon dioxide labeled with 14C is accidentally released into the atmosphere surrounding industrial workers as they resume work following the lunch hour. Unknowingly, they breathe the contaminated air for 1 hour. Which of the following compounds will be radioactively labeled?
A) About one half of the carbon atoms of newly synthesized fatty acids.
B) All of the carbon atoms of newly synthesized fatty acid.
C) The carboxyl atom of newly synthesized fatty acids.
D) One half of the carbon atoms of newly synthesized acetyl CoA.
E) About one third of the carbons of newly synthesized malonyl CoA.

Answer 1

Answer:

D) One half of the carbon atoms of newly synthesized acetyl CoA.

Explanation:

It will be radioactively labeled because Malonyl CoA which contains 3 Carbon molecule is synthesized from Acetyl CoA which has 2 Carbon molecule.

This happens with the addition of ‘CO2’ with the help of the enzyme called acetyl CoA carboxylase.