ATP

Question 1

What is a single molecule ATP known to be a derivative of?

Answer 1

• Single molecule of ATP = nucleotide derivative.

Question 2

What does ATP stand for?

Answer 2

• Adenosine triphosphate

Question 3

What is ATP compromised of/ formed from?

Answer 3

• Adenine - nitrogen- containing base.
• Ribose - pentose sugar.
• Three inorganic (don’t contain carbon) phosphate groups.

() - extra info for clarification

Question 4

What are inorganic phosphate groups often written as?

Answer 4

• P(small i- subscript)

Question 5

Why is ATP extremely important?

Answer 5

• Immediate source of energy for biological processes. Metabolic reactions, in cells, must have a steady, constant supply of ATP.

Question 6

In what reactions are ATP made (ie. both animals/ plants?) Outline the details of the formation of ATP by this reaction

Answer 6

• Respiration/ photosynthesis
• Addition of inorganic phosphate group to ADP -adenosine diphosphate -(only has two phosphate groups before reaction.) via a condensation reaction using enzyme **ATP synthase. **
• This process** requires** a small amount of energy.

() - extra info for clarification

Question 7

What is the role of ATP synthase?

Answer 7

• Enzyme that catalyses condensation reaction between ADP and inorganic phosphate group.

Question 8

Outline the reaction of hydrolysis of ATP.

Answer 8

• Hydrolysis of ATP to ADP (adenosine diphosphate) and inorganic phosphate group (Pi) is catalysed by enzyme ATP hydrolase.
• Breaking one of bonds between inorganic phosphate groups (during hydrolysis) releases small amount of energy to surroundings, which can be used for chemical reactions.

Question 9

Why is ATP known to be “immediate energy- source”?

Answer 9

• ATP = immediate energy- source because only 1 bond needs to be hydrolysed (one of bonds between inorganic phosphate groups) to release energy.

Question 10

Other than ATP releasing energy to surroundings that can be used in energy- requiring reactions within cells, what else can ATP do?

Answer 10

• ATP can **transfer ** energy to different compounds.
• The inorganic phosphate released during hydrolysis of ATP can be bonded onto/ phosphorylate different compounds to (often) make them more reactive. This is known as phosphorylation.

Question 11

What is the role of ATP hydrolase?

Answer 11

• Catlayses hydrolysis of ATP to ADP and Pi (inorganic phosphate group.)

Question 12

Compare ATP vs glucose as an energy source in terms of amount of energy released by the two sources.

Answer 12

• ATP releases small, manageable amounts of energy - so no energy is wasted. Cells won’t overheat from wasted heat energy/ run out of resources.
• WHEREAS, glucose releases a lot of energy that could result in wasted energy.

Question 13

Compare ATP vs glucose as an energy source in terms of amount solubility .

Answer 13

• ATP = small/ soluble molecule - can easily be transported around cell in cytoplasm to provide energy for chemical reactions in cell.
• Glucose is also soluble/small so can also be easily transported around the cell.

Question 14

Compare ATP vs glucose as an energy source in terms of immediacy in releasing energy.

Answer 14

• ATP: only 1 bond (between phosphate groups) needs to be broken to release energy. This is why energy- released is “immediate.”
• Glucose would need several bonds broken down to release all its energy.

Question 15

Compare ATP vs glucose as an energy source in terms of transferring energy.

Answer 15

• ATP can transfer energy to another molecule by transfering one of its phosphate groups phosphorylation.
• Glucose cannot do this as doesn’t contain any phosphate groups.

Question 16

Compare ATP vs glucose as an energy source in terms of movement in and out of cell.

Answer 16

• ATP: can’t pass out of the cell (so, cells will have a constant supply of ATP or ADP + Pi.)
• Glucose can pass out of cell/ enter cell (so, cell could run out of glucose.)