ATP

Question 1

describe how an ATP molecule is made from its component molecules (4)

Answer 1

1 and 2. ATP made from ribose, adenine, 3 phosphates
3. condensation reaction joins them
4. catalysed by ATP synthase

Question 2

name the two products of ATP hydrolysis

Answer 2

1. adenosine diphosphate
2. inorganic phosphate

Question 3

name the enzyme that:
- hydrolyses ATP
- makes ATP

Answer 3

• ATP hydrolase
  -ATP synthase

Question 4

give 4 ways ATP is a suitable energy source for cells (4)

Answer 4

1. releases relatively small amount of energy- little energy lost as heat
2. releases energy immediately
3. phosphorylates other compounds, makes them more reactive
4. is not lost from cells

Question 5

describe how ATP is resynthesised in cells (2)

Answer 5

• from ADP and phosphate
• by ATP synthase
• during respiration/ photosynthesis

Question 6

give 2 ways the hydrolysis of ATP is used in cells

Answer 6

1. to provide energy for reactions, E.g respiration
2. to add phosphate to other substances and make them more reactive

Question 7

describe the role of ATP in translation in protein synthesis (2)

Answer 7

1. provides energy
2. for the formation of peptide bonds between amino acids

Question 8

how is ATP used in active transport?

Answer 8

• binds to carrier protein and changes it’s shape
• allows molecules and ions to be moved against their concentration gradient

Question 9

Give two ways in which the properties of ATP make it a suitable source of energy in biological processes. (2)

Answer 9

1. Energy released in small / suitable amounts;
2. Soluble;
3. Involves a single / simple reaction;

Question 10

Humans synthesise more than their body mass of ATP each day. Explain why it is necessary for them to synthesise such a large amount of ATP. (2)

Answer 10

1. ATP cannot be stored / is an immediate source of energy;
2. ATP only releases a small amount of energy at a time

Question 11

Give two advantages of ATP as an energy-storage molecule within a cell (2)

Answer 11

Cannot pass out of cell;

Immediate source of energy;

releases small amounts of energy

Question 12

Mitochondria in muscle cells have more cristae than mitochondria in skin cells.
Explain the advantage of mitochondria in muscle cells having more cristae. (2)

Answer 12

larger surface area for electron transport chain

muscle cells use more ATP than skin cells

Question 13

When glucose is respired what happens to the energy which is not incorporated into ATP? (1)

Answer 13

released as heat

Question 14

how does ATP store energy ?

Answer 14

-bonds between phosphate groups have low activation energy

-they are easily broken and release a considerable amount of energy when broken

Question 15

Why is ATP a better immediate energy source than glucose?

Answer 15

• ATP releases less energy
• smaller/more manageable quantities
• hydrolysis of ATP is a single reaction whereas glucose breakdown is multiple reactions
• energy release takes longer

Question 16

5 processes ATP is used for in cells

Answer 16

• metabolic processes (energy to build up macromolecules)
• movement (energy for muscle contraction)
• active transport (change shape of carrier proteins in the plasma membrane)
• secretion (forms lysosomes)
• activation of molecules (phosphorylating other molecules to make them more reactive)