Answer to Question #124820 in Biochemistry for Sreelakshmi

Question

Why is the beta-D-glucopyranose form of glucose more abundant than alpha-D-glucopyranose in aqueous solution?

Answer 1

Answer :- Beta-D-glucopyranose form of glucose more abundant than alpha-D-glucopyranose in aqueous solution, this statement is correct and it can be explained as-

Explanation:- Glucose in a solution have found in both alpha and beta anomeric form, and in their structure only difference of position of -OH group at C-1 carbon.

In alpha-D-glucopyranose, this Hydroxyl -OH group is in the axial position at carbon no.1(C-1) anomeric centre, and apart from this, in

Beta-D-glucopyranose this hydroxyl

-OH group is in Equatorial position at the Carbon no.1 or C-1, anomeric centre.

And general rule of stability say that" A bulky group are more stable at they present at equatorial position and consequence of it to minimise steric hinderance.

So at equilibrium substituents in a cyclohexane ring (which is in chair form more stable) preferentially occupied equatorial, rather than axial, and minimised steric strain .

So due to -OH group of Beta-D-glucopyranose at C-1 anomeric carbon centre is more stable in their more stable chair form , rather than alpha-D-glucopyranose form of glucose molecule. And which is more stable molecules abundancy of that molecule also increased.

So Beta-D-glucopyranose form of glucose in solution are in more abundant than alpha-D-glucopyranose.