3.1.6 ATP

Question 1

Describe the structure of ATP

Answer 1

Nucleotide derivative of adenine with 3 phosphate groups , 1 molecule of adenine and 1 molecule of ribose

Question 2

Explain the role of ATP in cells

Answer 2

ATP hydrolase catalyse ATP = ADP + Pi
- Energy 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 respiration and photosynthesis

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 so less energy is wasted as heat
• Single-step hydrolysis means energy is available quickly
• Readily resynthesised