AP BIOLOGY

LABORATORY REVIEW

MOLECULAR BIOLOGY

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
A polymer of alpha-D-glucose found in plants has mostly 1, 4 linkages and some 1, 6 linkages. Which molecule fits this description?
A
Glycogen
B
Cellulose
C
Amylose
D
Amylopectin
Explanation: 

Detailed explanation-1: -Amylopectin is a branched polymer of -d-glucopyranosyl units. As in amylose, the backbone of amylopectin is linked by -(1, 4’) glycosidic bonds. The branches in amylopectin link short chains of amylose by -(1, 6’) glycosidic bonds.

Detailed explanation-2: -Glycogen is a polysaccharide that consists entirely of glucose molecules that are linked by two types of bonds-the alpha-1, 4-glycosidic bond and the alpha-1, 6-glycosidic bond.

Detailed explanation-3: -Amylopectin consists of -1–4 linked d-glucopyranose linear chains that are connected by -1–6 branch linkages, about 5%. The molecule is highly branched and has a molecular size about DP 106.

Detailed explanation-4: -So, the correct answer is ‘Glycogen’.

Detailed explanation-5: -Starch is made up of glucose monomers that are joined by 1-4 or 1-6 glycosidic bonds. The numbers 1-4 and 1-6 refer to the carbon number of the two residues that have joined to form the bond.

There is 1 question to complete.