Polysaccharides and their functions

Overview

Amylose, amylopectin, glycogen and cellulose, and how the shape of each one suits it to energy storage in plants and animals or to structural support.

What you need to know

Answer each one before you reveal it.

Questions from this subtopic

Each one with the model answer underneath.

1. 1

   What two polysaccharides make up starch?

   Model answer

   Amylose and amylopectin.

2. 2

   Describe the structure of amylose.

   Model answer

   An unbranched helical chain of α-glucose molecules joined by 1,4-glycosidic bonds.

3. 3

   Describe the structure of amylopectin.

   Model answer

   A branched chain of α-glucose molecules with 1,4-glycosidic bonds in the main chain and 1,6-glycosidic bonds at branch points.

4. 4

   Describe the structure of glycogen.

   Model answer

   A highly branched polysaccharide of α-glucose molecules with 1,4-glycosidic bonds in chains and 1,6-glycosidic bonds at frequent branch points.

5. 5

   Describe the structure of cellulose.

   Model answer

   An unbranched chain of β-glucose molecules joined by 1,4-glycosidic bonds, with alternate glucose molecules inverted.

6. 6

   Why is glucose used as a respiratory substrate?

   Model answer

   Glucose is soluble and can be transported to cells where it is broken down to release energy in both prokaryotes and eukaryotes.

Other ways to work this

The same content, four other ways.

What is inside Levo

Six ways to work the same material.