What enzyme converts glucose into sorbitol in the metabolic pathway associated with diabetes?

The correct response is based on the metabolic pathway that involves the conversion of glucose into sorbitol, which is particularly relevant in the context of diabetes. Aldose reductase is the enzyme responsible for catalyzing this reaction. It reduces glucose to sorbitol using NADPH as a cofactor. This process is part of the polyol pathway, which can lead to sorbitol accumulation in tissues when glucose levels are high, such as in uncontrolled diabetes. Excess sorbitol can contribute to diabetic complications, including retinopathy and neuropathy.

Other enzymes listed do not participate in the conversion of glucose to sorbitol. For instance, sorbitol dehydrogenase converts sorbitol to fructose but does not act on glucose. Fructokinase is implicated in the phosphorylation of fructose, while hexokinase phosphorylates glucose to glucose-6-phosphate as part of glycolysis. Therefore, aldose reductase is the key enzyme in this specific metabolic pathway related to diabetes and the correct choice.