Question

The free energy required to synthesize a mixed anhydride bond of 1,3-bisphosphoglycerate is generated by the oxidation of ________.

• A. an aldehyde to acid
• B. an alcohol to acid
• C. an alcohol to aldehyde
• D. NADH to NAD\(^+\)

Hint:

Oxidation reactions, such as the conversion of aldehydes to acids, are often coupled with energy-producing reactions in biochemical pathways.

Answer 1

The Correct Option is A

Step 1: Understanding the process.
The oxidation of aldehydes to acids is a crucial step in the metabolism of 1,3-bisphosphoglycerate, where energy is released. This energy is used to form the high-energy mixed anhydride bond.
Step 2: Analyzing the options.
(A) an aldehyde to acid: Correct — The oxidation of aldehydes to acids generates the necessary energy for the bond formation.
(B) an alcohol to acid: Incorrect — This does not apply to the generation of the mixed anhydride bond in the case of 1,3-bisphosphoglycerate.
(C) an alcohol to aldehyde: Incorrect — This is not related to the generation of the anhydride bond.
(D) NADH to NAD\(^+\): Incorrect — While NADH oxidation is essential in metabolism, it does not directly generate the mixed anhydride bond.
Step 3: Conclusion.
The correct answer is (A) an aldehyde to acid, as this oxidation reaction releases energy used to form the mixed anhydride bond.