[Unit 2.3] | Energy And ATP

Question 1

What does ATP stand for?

Answer 1

Adenosine Triphosphate.
(Adenine + Ribose + 3 Phosphate Groups)

Question 2

What are the prefixes (x phosphate) for nucleotides with 1-3 phosphate groups?

Answer 2

• 1: Monophosphate
• 2: Diphosphate
• 3: Triphosphate

Question 3

How does ATP store energy?

Answer 3

• Bonds between the 3 phosphate groups are unstable and have a low activation energy.

• When their bonds are easily broken, a considerable amount of energy is released.

Question 4

Give the symbol equation for the hydrolysis of ATP & the enzyme used.

Answer 4

• ATP + H2O -> ADP + Pi + E
• Enzyme: ATP hydrolase

• Pi = Inorganic Phosphate
• E = 30.5kJ Energy

Question 5

Give the symbol equation for the synthesis of ATP & the enzyme used.

Answer 5

• ADP + Pi + E -> ATP + H2O
• Enzyme: ATP Synthase

• Process requires energy as it is endothermic.

Question 6

Why is ATP a better immediate store of energy than glucose? (2)

Answer 6

• ATP releases energy in smaller & more manageable quantities.

• Hydrolysis of ATP to ADP is a single step, so release of energy is faster.

Question 7

What must cells do in order to meet the requirement of ~50kg of ATP per day when the body can only hold ~200g?

Answer 7

• Cells produce it via respiration when it is needed.

Question 8

List 5 examples of ATP use in the body.

Answer 8

• Anabolic reactions
• Active transport
• Anaphase
• Muscle contraction
• Nerve impulses