Question

how does nad+ transform during cellular respiration? it gains a hydrogen ion. it gains neutrons. it is converted into atp. it loses a proton.

Explanation:

To determine how NAD+ transforms during cellular respiration, we analyze each option:

• Option "It gains a hydrogen ion": During cellular respiration, NAD+ (nicotinamide adenine dinucleotide) acts as an electron carrier. It accepts a hydrogen ion (H⁺) and two electrons, becoming NADH. This is a key part of the redox reactions in glycolysis, the Krebs cycle, etc.
• Option "It gains neutrons": Neutrons are part of atomic nuclei, and NAD+ transformation in cellular respiration does not involve gaining neutrons. This is incorrect.
• Option "It is converted into ATP": NAD+ is involved in generating ATP (by carrying electrons to the electron transport chain which helps create the proton gradient for ATP synthesis), but NAD+ itself is not converted into ATP. ATP is synthesized from ADP and phosphate, so this is incorrect.
• Option "It loses a proton": NAD+ gains a hydrogen ion (which includes a proton and an electron in the context of redox), it does not lose a proton. This is incorrect.

Answer:

A. It gains a hydrogen ion.