3.1.6 ATP

Question 1

What type of molecule is ATP and what is it formed from?

Answer 1

ATP is a nucleotide derivative formed from a molecule of ribose a molecule of adenine and three phosphate groups

Question 2

What enzyme catalyses the hydrolysis of ATP to ADP and Pi?

Answer 2

ATP hydrolase

Question 3

What are the products of ATP hydrolysis?

Answer 3

Adenosine diphosphate (ADP) and an inorganic phosphate (Pi)

Question 4

What can the hydrolysis of ATP be coupled to?

Answer 4

Energy-requiring reactions within cells

Question 5

How does the inorganic phosphate released during ATP hydrolysis affect other compounds?

Answer 5

It phosphorylates them often making them more reactive

Question 6

How is ATP resynthesised?

Answer 6

By the condensation of ADP and Pi catalysed by ATP synthase during photosynthesis or respiration

Question 7

Describe how an ATP molecule is formed from its component molecules

Answer 7

1. and 2. Accept for 2 marks correct names of three components adenine,
   ribose/pentose, three phosphates;;

Accept for 1 mark, correct name of two components

Accept for 1 mark, ADP and phosphate/Pi
Ignore adenosine

Accept suitably labelled diagram

3. Condensation (reaction);
   Ignore phosphodiester
4. ATP synthase;
   Reject ATPase

Question 8

Name the two products of ATP hydrolysis.

Answer 8

Adenosine diphosphate and (inorganic) phosphate;

Question 9

Describe how ATP is resynthesised in cells

Answer 9

1. From ADP and phosphate;
   Accept
   Reject P/Phosphorus
   Reject use of water in the reaction
2. By ATP synthase;
3. During respiration/photosynthesis;

Question 10

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

Answer 10

1. To provide energy for other reactions/named process;

Reject ‘produce’ energy

2. To add phosphate to other substances and make them more
   reactive/change their shape;

Question 11

Describe the structure of ATP.
Outline how named enzymes break down and resynthesise ATР.

Answer 11

1. Ribose, Adenine and 3 phosphates;
2. ATP to ADP + Pi by ATP hydrolase in hydrolysis (reaction);
3. ADP + Pi to ATP by ATP synthase;
4. (In)condensation(reaction);