1.4 - Starch, Glycogen And Cellulose

Question 1

How does cellulose differ from starch and glycogen?

Answer 1

Cellulose is made of β-glucose monomers instead of α-glucose.

Question 2

How does the structure of cellulose differ from starch?

Answer 2

Cellulose has straight, unbranched chains, whereas starch forms coiled chains.

Question 3

What is the arrangement of cellulose chains, and why is it important?

Answer 3

Cellulose chains run parallel and form cross-linkages via hydrogen bonds, contributing significantly to the molecule’s strength.

Question 4

What unique feature is present in the β-glucose arrangement in cellulose?

Answer 4

Adjacent glucose molecules in cellulose are rotated 180°, allowing hydrogen bonds to form between hydroxyl groups on adjacent chains.

Question 5

How are cellulose molecules organized?

Answer 5

Cellulose molecules group to form microfibrils, which are arranged in parallel groups called fibres.

Question 6

What is the role of cellulose in plant cells?

Answer 6

• Provides rigidity and prevents cell bursting by exerting inward pressure, limiting water intake via osmosis.
• Ensures turgid cells, maintaining semi-rigid plant structures for maximum photosynthesis.

Question 7

Why is the structure of cellulose suited for its function?

Answer 7

• Made of β-glucose, forming long, straight, unbranched chains.
• Chains are parallel and cross-linked by hydrogen bonds for collective strength.
• Molecules form microfibrils and fibres, adding further structural strength.