1.6 ATP

Question 1

What does the structure of ATP look like?

Answer 1

• Ribose, a molecule of adenine, 3 phosphate groups
• Nucleotide derivative
• The structure of ADP (adenosine diphosphate) is the same as ATP, minus a phosphate

Question 2

Describe ATP hydrolysis and what catalyses it

Answer 2

ATP -> ADP + Pi
- Catalysed by the enzyme ATP hydrolase
- Can be coupled to energy requiring reactions within cells, to provide energy for active transport, protein synthesis,etc. (energy released when bonds between inorganic phosphate groups are broken)
- The inorganic phosphate released can be used to phosphorylate other compounds eg/glucose, of ten making them more reactive (i.e. lowers activation energy)

Question 3

Describe ATP condensation and what catalysis it uses

Answer 3

ADP + Pi -> ATP
- Catalysed by the enzyme ATP synthase
- Happens during respiration or photosynthesis
- Also called phosphorylation of ADP

Question 4

What properties of ATP make it a suitable immediate source of energy?

Answer 4

IMPORTANT - ATP cannot be stored
- ATP releases energy in small, manageable amounts (so no energy wasted)
- Only one bond is hydrolysed to release energy (which is why energy release is immediate)