Question

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; apoenzymeb. cofactor; holoenzymec. coenzyme; apoenzymed. coenzyme; holoenzymecofactor

Answer 1

When the ion is present in the enzyme, the ion is a cofactor and the enzyme is an holoenzyme.

Step-by-step explanation:

A great number of enzymes require cofactors for its function. A cofactor is a small molecule- it can be a metallic ion or an organic molecule- which binds to a proteic structure to form the active enzyme. The protein alone, without cofactor, is called apoenzyme and the complex cofactor-apoenzyme is called holoenzyme. In general, a coenzyme is a vitamin and carries a functional group which is required in the reaction to be catalyzed. In this case, the Cu²⁺ ion is a cofactor.