question_answer

Which one of the following sets of monosaccharide’s forms sucrose? [AIPMT (S) 2012]

A) \[\text{ }\!\!\alpha\!\!\text{ -}\]D-galactopyranose and \[\text{ }\!\!\alpha\!\!\text{ -}\]D-glucopyranose

B) \[\text{ }\!\!\alpha\!\!\text{ -}\]D-glucopyranose and \[\text{ }\!\!\beta\!\!\text{ -}\]D-fructofuranose

C) \[\text{ }\!\!\beta\!\!\text{ -}\]D-glucopyranose and \[\text{ }\!\!\alpha\!\!\text{ -}\]D-fructofuranose

D) \[\text{ }\!\!\alpha\!\!\text{ -}\]D-glucopyranose and \[\text{ }\!\!\beta\!\!\text{ -}\]D-fructopyranose

Correct Answer: A

Solution :

[a] Sucrose is composed of a-D-glucopyranose and a fructofuranose units which are joined by ,glycoside linkage between C-l of the glucose unit and C-2 of the fructose unit.