ATP

Question 1

Structure of ATP

Answer 1

Ribose, molecule of adenine and 3 phosphate groups

Question 2

ATP hydrolysis?

Answer 2

ATP (+water) —>ADP+Pi

Catalysed by ATP hydrolase
Can be coupled to energy requiring reactions within cells to provide energy e.g. Active transport or protein synthesis.

This happens when the bonds between inorganic phosphate groups are high energy bonds so by breaking one of these bonds a small amount of energy is released.

The inorganic phosphate released can be used to phosphorylate other compounds by making them more reactive e.g. glucose (lowers activation energy)

Question 3

ATP synthesis

Answer 3

ADP+Pi—–> ATP
Condensation reaction
Catalysed by enzyme ATP synthase
Happens during respiration or photosynthesis.

It occurs in 3 ways:
Photophosphorylation
Oxidative phosphorylation
Substrate level phosphorylation

Question 4

What properties of ATP make it suitable for immediate source of energy

Answer 4

ATP releases energy in small, manageable amounts (so no energy wasted)

Only one bond is hydrolysed (single reaction) to release energy (which is why energy release is Immediate)

ATP cannot be stored so is used immediately.