ATP

Question 1

describe the structure of ATP

Answer 1

• adenine (a nitrogenous base)
• ribose sugar
• 3 phosphate groups

Question 2

what are the two roles of ATP?

Answer 2

1. to release energy to power energy-requiring processes within the cell
2. to phosphorylate molecules to make them more reactive

Question 3

describe how ATP can release energy to power energy-requiring processes within the cell

Answer 3

there is a short term energy store of the cell, when hydrolysed it releases a small, manageable amount of energy that can be used to power cell processes that require energy

Question 4

describe how ATP can phosphorylate molecules to make them more reactive?

Answer 4

when ATP is hydrolyses the phosphate can be added to other molecules

Question 5

how does ATP release energy?

Answer 5

• the bonds between the 3 phosphate groups are unstable and so are easily broken
• when the bond between the last two phosphate groups is broken, ATP is hydrolysed to ADP and Pi
• this releases a small, manageable amount of energy to power cell processes
• this is catalysed by the enzyme ATP hydrolase
• ADP can be converted back to ATP by the addition of a phosphate group using the enzyme ATP synthase

Question 6

where does ATP synthesis take place?

Answer 6

• in chloroplasts during photosynthesis (photophosphorylation)
• during respiration (oxidative phosphorylation)
• when phosphate groups are transferred from donor molecules to ADP (substrate level phosphorylation