3.1.5: ATP and water

Question 1

Describe the Uses and properties of ATP as an energy
source (5)

Answer 1

1. Releases relatively small amount of energy / little
   energy lost as heat;
2. Releases energy instantaneously;
3. Phosphorylates other compounds, making them
   more reactive;
4. Can be rapidly re-synthesised;
5. Does not leave cells;

Question 2

Describe the structure of ATPs Structure compared with DNA nucleotide (3)

Answer 2

1. ATP has ribose and DNA has deoxyribose;
2. ATP has 3 phosphates and DNA nucleotide has
   one phosphate;
3. Base is always adenine in ATP and bases vary in
   DNA nucleotide (A,C,G or T);

Question 3

Describe the Properties that make water
important for organisms (6)

Answer 3

1. A metabolite in
   condensation/hydrolysis/photosynthesis/respiration;
2. A solvent so (metabolic) reactions can occur;
3. High heat capacity so buffers changes in
   temperature;
4. Large latent heat of vaporisation so provides a
   cooling effect (through evaporation);
5. Cohesion (between water molecules) so supports
   columns of water (in plants);
6. Cohesion (between water molecules) so produces
   surface tension supporting organisms;