Carbohydrates Exam Questions

Question 1

Glycogen and cellulose are both carbohydrates.
Describe two differences between the structure of a cellulose molecule and a glycogen molecule. (2)

Answer 1

Cellulose is made up of β-glucose (monomers) and glycogen is made up of α-glucose (monomers)

Cellulose molecule has straight chain and glycogen is branched

Question 2

Starch is a carbohydrate often stored in plant cells.
Describe and explain two features of starch that make it a good storage molecule. (2)

Answer 2

Branched / coiled / (α-)helix, so makes molecule compact

Polymer of (α-)glucose so provides glucose for respiration

Question 3

Describe the structure of glycogen. (2)

Answer 3

Polysaccharide of α-glucose

joined by glycosidic bonds

Question 4

Suggest how glycogen acts as a source of energy.
Do not include transport across membranes in your answer. (2)

Answer 4

Hydrolysed (to glucose)

Glucose used in respiration

Question 5

Name the monomers from which a maltose molecule is made. (1)

Answer 5

Glucose and glucose

Question 6

Explain one way in which starch molecules are adapted for their function in plant cells. (2)

Answer 6

The structure is helical which makes it compact