ATP

Question 1

What is ATP

Answer 1

Adenosine triphosphate

Question 2

Describe the structure of ATP

Answer 2

● Ribose bound to a molecule of adenine and 3 phosphate groups
● Nucleotide derivative

Question 3

Describe how ATP is broken down

Answer 3

● ATP → ADP (adenosine diphosphate) + Pi (inorganic phosphate)
● Hydrolysis reaction, using a water molecule
● Catalysed by ATP hydrolase (enzyme)

Question 4

Give two ways in which the hydrolysis of ATP is used in cells

Answer 4

● Coupled to energy requiring reactions within cells (releases / provides energy)
○ Eg. active transport, protein synthesis
● Inorganic phosphate released can be used to phosphorylate (add phosphate
to) other compounds, making them more reactive

Question 5

Describe how ATP is resynthesised in cells

Answer 5

● ADP + Pi → ATP
● Condensation reaction, removing a water molecule
● Catalysed by ATP synthase (enzyme)
● During respiration and photosynthesis

Question 6

Suggest how the properties of ATP make it a suitable immediate source of
energy for cells

Answer 6

● Releases energy in (relatively) small amounts / little energy lost as heat
● Single reaction / one bond hydrolysed to release energy (so immediate release)
● Cannot pass out of cell