3.1.6 ATP

Question 2

What is ATP?

Answer 2

A nucleotide derivative, formed from a molecule of ribose, a molecule of adenine and three phosphate groups

Question 3

What is ATP hydrolysed into and what enzyme catalyses this reaction?

Answer 3

• an inorganic phosphate group and ADP- one molecule of ribose, one molecule of adenine and two phosphate groups
• ATP hydrolase

Question 4

How can the hydrolysis of ATP be coupled to energy requiring reaction within cells?

Answer 4

• Direct coupling
  The hydrolysis of ATP releases energy which can be used in energy requiring reactions
• Phosphorylation
  Released inorganic phosphate bonds to a compound in order to make it more reactive

Question 5

How is ATP resynthesised?

Answer 5

• photophosphorylation- occurs in plants during photosynthesis
• oxidative phosphorylation- occurs in animals during respiration
• substrate level phosphorylation- occurs in plants and animals when phosphate groups are transferred from donor molecules to ADP
• This reaction is catalysed by the enzyme ATP synthase

Question 6

Give three ways in
which ATP is a suitable energy source for cells to use.

Answer 6

• Phosphorykates other compounds making them more reactive
• Immediate source of energy
• can be rapidly resynthesied
• is not lost from cells