Question

Enzyme alternate oxidase is inhibited by

• A. NADP
• B. SHAM (Salicyl hydroxamic acid)
• C. Both A and B
• D. None of these

Answer 1

The correct option is B SHAM (Salicyl hydroxamic acid)

Alternative oxidase (AOX) is a terminal oxidase enzyme which does not conserve energy in the plant mitochondrial electron transport chain. The oxidase provides an alternative route for electrons passing through the electron transport chain to reduce oxygen.This enzyme does not translocate H⁺ and is, therefore, is not linked to ATP formation. The enzyme is a quinol oxidase and appears to consist of one to three polypeptides and is insensitive to carbon monoxide and cyanide. However, Cyanide-insensitive O₂ uptake is inhibited by hydroxamic acids (SHAM — salicyl hydroxamic acid).

So, the correct answer is option B.