What coupling enzyme is used in the hexokinase method for glucose measurement?

What coupling enzyme is used in the hexokinase method for glucose measurement?

• A. Glucose-6-phosphate dehydrogenase
• B. Peroxidase
• C. Glucose dehydrogenase
• D. Glucose-6-phosphatase

Answer: (A)

The hexokinase method for glucose measurement utilizes glucose-6-phosphate dehydrogenase as the coupling enzyme. In this biochemical method, glucose is phosphorylated by hexokinase to form glucose-6-phosphate. This is the critical first step in the process. Subsequently, glucose-6-phosphate is oxidized by glucose-6-phosphate dehydrogenase, producing 6-phosphoglucono-lactone along with the conversion of an NADP+ molecule to NADPH. This reaction is vital because the generation of NADPH can be quantitatively measured, providing a direct and sensitive assessment of glucose concentration in the sample. The increase in NADPH correlates with the amount of glucose present, making it a reliable method for glucose measurement in clinical settings. In contrast, although other enzymes listed may play roles in different metabolic pathways, they are not part of the specific mechanism utilized in the hexokinase method for glucose quantification.

The hexokinase method for glucose measurement utilizes glucose-6-phosphate dehydrogenase as the coupling enzyme. In this biochemical method, glucose is phosphorylated by hexokinase to form glucose-6-phosphate. This is the critical first step in the process. Subsequently, glucose-6-phosphate is oxidized by glucose-6-phosphate dehydrogenase, producing 6-phosphoglucono-lactone along with the conversion of an NADP+ molecule to NADPH.

This reaction is vital because the generation of NADPH can be quantitatively measured, providing a direct and sensitive assessment of glucose concentration in the sample. The increase in NADPH correlates with the amount of glucose present, making it a reliable method for glucose measurement in clinical settings.

In contrast, although other enzymes listed may play roles in different metabolic pathways, they are not part of the specific mechanism utilized in the hexokinase method for glucose quantification.