1.6 ATP

Question 1

ATP is…

Answer 1

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

Question 2

Hydrolysis of ATP to adenosine diphosphate (ADP) and an inorganic phosphate group (Pi) is catalysed by…

Answer 2

ATPase enzymes such as ATP hydrolase.

Question 3

ATP is the universal energy source for cellular processes because…

Answer 3

1. the hydrolysis of ATP can be coupled to energy-requiring reactions within cells.
2. the hydrolysis of ATP releases energy in small / suitable amounts;
3. the hydrolysis of ATP is a one-step reaction / single bond broken / makes energy available rapidly / is an immediate source of energy;
4. ATP can be resynthesised; [Nb: ATP is not reformed ‘easily’ - respiration is one of the most complex processes you learnt]

Question 4

How can ATP be used to make other compounds more reactive?

Answer 4

The inorganic phosphate released during the hydrolysis of ATP can be used to phosphorylate other compounds, often making them more reactive / lowering the activation energy of the reaction

Question 5

How can ATP be used to activate proteins?

Answer 5

The inorganic phosphate released during the hydrolysis of ATP can be used to phosphorylate the protein, changing its tertiary structure.

Question 6

ATP is resynthesised by the condensation of ADP and Pi. This reaction is catalysed by what enzyme, and when?

Answer 6

This reaction is catalysed by the enzyme ATP synthase during photosynthesis, or during respiration.