Polysaccharides

Question 1

What are the three main polysaccharides?

Answer 1

-cellulose
-starch (amylose and amylopectin)
-glycogen

Question 2

describe the polysaccharide cellulose

Answer 2

-source: plants cell walls
-subunits: Beta glucose
-bonds: glycosidic 1,4 bonds
-no branching
-beta glucose rotated for each bond
-straight chains, hydrogen cross linkages
-tough, insoluble, fibrous

Question 3

describe amylose the polysaccharide

Answer 3

-source: plant, starch grains
-subunit: alpha glucose
-bonds- glycosdic 1,4 bonds
-no branching
-forms helix= compact
-hydrogen bonds

Question 4

describe the polysaccharide amylopectin

Answer 4

-source: plants, starch grains
-subunit: alpha glucose
-bonds: glycosidic 1,4 and 1,6
-branching per 20 subunits
-branched so very compact
-hydrogen bonds

Question 5

describe the polysaccharide glycogen

Answer 5

-source: animals liver and muscle cells
-subunit: alpha glucose
-bonds: 1,4 and 1,6 glycosidic
-highly branched, per 10 subunits
-very compact
-individual glucose molecules removed by hydrolysis to provide glucose for respiration.

Question 6

explain how the structure of glycogen differs from that of amylopectin to make it better suited as an energy store in animals

Answer 6

glycogen is more highly branched than amylopectn due to 1,4 and 1,6 glycosidic bonds
also it is more coiled
this makes glycogen more compact aswell as easier to hydrolyse for glucose in respiration