Reactions
Aldose reductase catalyzes the NADPH-dependent conversion of glucose to sorbitol, the first step in polyol pathway of glucose metabolism. The second and last step in the pathway is catalyzed by sorbitol dehydrogenase, which catalyzes the NAD-linked oxidation of sorbitol to fructose. Thus, the polyol pathway results in conversion of glucose to fructose with stoichiometric utilization of NADPH and production of NADH.
- glucose + NADPH + H+ → sorbitol + NADP+
Galactose is also a substrate for the polyol pathway, but the corresponding keto sugar is not produced because sorbitol dehydrogenase is incapable of oxidizing galactitol. Nevertheless, aldose reductase can catalyze the reduction of galactose to galactitol
- galactose + NADPH + H+ → galactitol + NADP+
Read more about this topic: Aldose Reductase
Famous quotes containing the word reactions:
“Separation anxiety is normal part of development, but individual reactions are partly explained by experience, that is, by how frequently children have been left in the care of others.... A mother who is never apart from her young child may be saying to him or her subliminally: “You are only safe when I’m with you.””
—Cathy Rindner Tempelsman (20th century)
“We have all had the experience of finding that our reactions and perhaps even our deeds have denied beliefs we thought were ours.”
—James Baldwin (1924–1987)
“Cuteness in children is totally an adult perspective. The children themselves are unaware that the quality exists, let alone its desirability, until the reactions of grownups inform them.”
—Leontine Young (20th century)