3.1.6 ATP

Question 1

what does ATP stand for?

Answer 1

adenosine triphosphate

Question 2

how does ATP relate to DNA?

Answer 2

a single molecule of ATP is a nucleotide derivative

Question 3

what does ATP contain?

Answer 3

a molecule of ribose, a molecule of adenine and three inorganic phosphate groups

Question 4

where is energy stored in and ATP molecule?

Answer 4

in the bonds between the phosphates

Question 5

what are the component molecules of ATP?

Answer 5

adenosine diphosphate (ADP) and an inorganic phosphate group (Pi)

Question 6

what happens when ATP is hydrolysed?

Answer 6

energy is released

Question 7

which enzyme catalyses the hydrolysis of ATP?

Answer 7

ATP hydrolase

Question 8

how is ATP resynthesised?

Answer 8

by the condensation of ADP and Pi during photosynthesis or respiration

Question 9

which enzyme catalyses the condensation reaction of ADP and Pi?

Answer 9

ATP synthase

Question 10

why is ATP an immediate energy source?

Answer 10

only one bond has to be hydrolysed to release energy

Question 11

what is phosphorylation in terms of ATP?

Answer 11

• the inorganic phosphate released during the hydrolysis of ATP can be bonded onto different compounds
• this makes them more reactive

Question 12

ATP can be reformed in a condensation reaction in which three ways?

Answer 12

• photophosphorylation: occurs in chlorophyll during photosynthesis
• oxidative phosphorylation: occurs in mitochondria during the electron transport chain
• substrate level phosphorylation: when the phosphate groups are transferred from donor molecules to ADP

Question 13

what are the five key properties of ATP?

Answer 13

• releases energy in small, manageable amounts
• small and soluble
• only one bond is hydrolysed to release energy
• can transfer energy to another molecule by transferring one of its phosphate groups
• can’t pass out of the cell

Question 14

why is it important that ATP releases energy in small, manageable amounts?

Answer 14

• no energy is wasted
• cells do not overheat from wasted energy and are less likely to run out of resources

Question 15

why is it important that ATP is small and soluble?

Answer 15

-it can be easily transported around the cell

Question 16

why is it important that ATP only requires one bond to be hydrolysed to release energy?

Answer 16

energy release is immediate

Question 17

why is it important that ATP can transfer energy to another molecule by transferring one of its phosphate groups?

Answer 17

enables phosphorylation to make other compounds more reactive

Question 18

why is it important that ATP can’t pass out of the cell?

Answer 18

• the cell has a constant supply of ATP or ADP + Pi
• this means that the cell always has an immediate supply of energy

Question 19

what are the four properties of glucose that make it unsuitable as an immediate energy source, compared to ATP?

Answer 19

• releases energy in large amounts so more energy wasted
• needs several bonds to be broken down to release all its energy
• cannot phosphorylate other compounds as it does not contain phosphate groups
• can leave the cell so the cell can run out of glucose