A Liver Enzyme Called Two-Substrate Inactivates a Drug by the Following

Multiple Choice

A liver enzyme called two-substrate inactivates a drug by the following reaction, where NADP is nicotinamide adenine dinucleotide phosphate and NADPH is the reduced form of NADP: Drug + NADPH ? Inactive product + NADP⁺
The Km and physiological substrate concentrations (both in millimoles per liter) are given in the table for both substrates.
What is the rate-limiting substrate under these conditions, and what is the derived Michaelis-Menten equation that describes the velocity of product formation by the enzyme?

A) Drug limiting; vo = Vmax.
B) NADPH limiting; 1/2 Vmax.
C) NADPH limiting; (Vmax x [NADPH]) /0.22 mmol.
D) Drug limiting; (Vmax x [Drug]) /0.12 mmol.
E) NADPH limiting; k2/Km.