Nitrite reductase contains two histidine amino acids that coordinate a Cu²⁺ ion.When the ion is present in the enzyme,the ion is a __________ and the enzyme is a __________. A) cofactor; apoenzyme B) cofactor; holoenzyme C) coenzyme; apoenzyme D) coenzyme; holoenzyme

Question

Quizplus · Accepted Answer

A cofactor is a non-protein molecule or ion that is required for the activity of an enzyme. In this case, the Cu²⁺ ion is a cofactor for the nitrite reductase enzyme. When the ion is present in the enzyme, it becomes a holoenzyme, which is the active form of the enzyme that includes all necessary components (including cofactors) for catalytic activity. Therefore, the correct answer is B: cofactor; holoenzyme.

Nitrite Reductase Contains Two Histidine Amino Acids That Coordinate a Cu2+

Nitrite Reductase Contains Two Histidine Amino Acids That Coordinate a Cu²⁺