[Campbell Biology P.218] Considering the redox reaction: C4H6O5 + NAD+ → C4H4O5 + NADH + H+,... | Practice Question

Considering the redox reaction: C4H6O5 + NAD+ → C4H4O5 + NADH + H+, as presented in Concept Check 9.1, which compound is oxidized and which is reduced?

  • A: C4H6O5 is oxidized, and NAD+ is reduced.
  • B: C4H6O5 is reduced, and NAD+ is oxidized.
  • C: Both C4H6O5 and NAD+ are oxidized.
  • D: Both C4H6O5 and NAD+ are reduced.

Explanation

In the reaction C4H6O5 → C4H4O5, the molecule C4H6O5 loses two hydrogen atoms and thus electrons , which signifies oxidation. Conversely, NAD+ gains these electrons and a hydrogen atom to become NADH, indicating that NAD+ is reduced. Oxidation is the loss of electrons or hydrogen atoms in biological systems , and reduction is the gain of electrons or hydrogen atoms .