Topic 1.6 - ATP

Question 1

What is ATP?

Answer 1

Adenosine triphosphate

Question 2

Describe the structure of ATP (2)

Answer 2

1) Ribose bound to a molecule of adenine (base) and 3 phosphate groups

2) Nucleotide derivative (modified nucleotide)

Question 3

Describe how ATP is broken down (3)

Answer 3

1) ATP -> ADP + Pi

2) Hydrolysis reaction, using a water molecule

3) Catalysed by ATP hydrolase

Question 4

Give 2 ways in which the hydrolysis of ATP is used in cells

Answer 4

1) Coupled to energy requiring reactions within cells
E.g. active transport, protein synthesis

2) Inorganic phosphate released can be used to phosphorylate other compounds, making them more reactive

Question 5

Describe how ATP is resynthesised in cells (4)

Answer 5

1) ADP + Pi

2) Condensation reaction, removing a water molecule

3) Catalysed by ATP synthase

4) During respiration and photosynthesis

Question 6

Describe how the properties of ATP make it a suitable immediate source of energy for cells (3)

Answer 6

1) Releases energy in small amounts / little energy is lost as heat

2) Single reaction / one bond hydrolysed to release energy (so immediate release)

3) Cannot pass out of cell