Answer to Question #125268 in Biochemistry for Arpan Das

Question

In aqueous solution, almost all D-glucose molecules are in the pyranose form. Other aldoses have a greater proportion of molecules in the open-chain form. D-Glucose may have evolved to be the predominant hexose because it is less likely than its isomers to react with and damage cellular proteins. Explain why D-glucose reacts less than other aldoses with the amino groups of proteins.

Answer 1

Only aldoses are present are in open chain conformation as they have free aldehyde and are able to form Schiff bases with amino group of proteins. As most of the D-glucose molecules in solution are closed-chain and only a few are in open-chain form. D-glucose has less probability than other aldoses to react with amino groups.