Energy And ATP

Question 1

What are the 3 parts of ATP?

Answer 1

Adenine (base)
Ribose (sugar with 5 carbon ring structure)
3 phosphates (chain)

It’s what’s known as a nucleotide derivative because it is a modified form of a nucleotide

Question 2

What does ATP stand for?

Answer 2

Adenosine triphosphate

Question 3

ATP is the immediate source of energy in a cell

Answer 3

Plant and animal cells respire. In respiration the energy released from glucose is used to make ATP. Once made ATP diffuses to the part of the cell that needs energy. The energy in ATP is stored in high energy bonds between the phosphate groups, it’s released via hydrolysis reactions.

Question 4

What happens when ATP is broken down?

Answer 4

When Energy is needed by a cell ATP is broken down into ADP and Pi (inorganic phosphate).
This is a hydrolysis reaction.(A phosphate bond is broken and energy is released. the reaction is catalysed by the enzyme ATP hydrolase)

Question 5

What chemical reaction forms ATP?

Need to know the equations for hydrolysis and condensation with this

Answer 5

A condensation reaction (ATP synthase)

Question 6

What are the three ways ATP can be made?

Answer 6

1) photophosphorylation
2) oxidative phosphorylation
3) substrate level phosphorylation

Question 7

Why is ATP not a long-term energy source?

Answer 7

Because it is unstable. ATP is an immediate energy source because there is only one reaction.

Question 8

Why is it not a problem that a cell only contains a few seconds supply of ATP?

Answer 8

Because it is reformed continuously from ADP plus Pi in respiration in mitochondria/photosynthesis

Question 9

Why is ATP a better immediate source of energy than glucose?

Answer 9

Because the right amount of energy is released and one reaction is needed.

Question 10

Is ATP big?

Answer 10

Yes ATP is bigger than glucose. The larger size of ATP is an advantage to the cell because it is formed and it cannot diffuse through the cell membranes.

Question 11

What biological processes can ATP be used for?

Answer 11

• Active transport (to change the shape of the carrier protein moving substance against concentration gradient)
• activation of molecules (phosphate added to glucose to make it more reactive for respiration and lower the activation energy)
• metabolic processes (which require energy)
• proteins required for movement (to slide over each other during muscle contraction and when spindle fibres contract)
• secretion (making lysosome/vesicles)