3.1.6 ATP

Question 1

Describe the structure of adenosine triphosphate (ATP).

Answer 1

A ribose sugar bonded to adenine and 3 phosphate groups.

Question 2

Explain the role of ATP in cells.

Answer 2

ATP hydrolase catalyses ATP forming ADP and Pi.
- Energy released is coupled to metabolic reactions.
- Phosphate group phosphorylates compounds to make them more reactive.

Question 3

How is ATP resynthesised in cells?

Answer 3

• ATP synthase catalyses condensation reaction between ADP and Pi
• During photosynthesis and respiration

Question 4

Explain why ATP is suitable as the ‘energy currency’ of cells.

Answer 4

• High energy bonds between phosphate groups.
• Small amounts of energy released at a time = less energy wasted as heat.
• Single-step hydrolysis = energy available
• Readily resynthesised.