ATP, water and inorganic ions

Question 1

describe how an ATP molecule is formed from is component molecules

Answer 1

1. adenine, ribose sugar, three phosphates
2. condensation reaction
3. ATP synthase

Question 2

what are the products of ATP hydrolysis?

Answer 2

adenosine diphosphate and inorganic phosphate

Question 3

suggest why human ATP synthase is not inhibited and bacterial synthase is inhibited

Answer 3

human ATP synthase has different tertiary structure

Question 4

how is ATP a suitable energy source for cells to use?

Answer 4

1. releases energy instantaneously
2. can be rapidly re-synthesised
   3.is not lost from the cells

Question 5

describe how ATP is resynthesised in cells

Answer 5

1.from ADP and phosphate
2. by ATP synthase
3. during respiration

Question 6

give two ways the hydrolysis of ATP is used in cells

Answer 6

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

Question 7

what is an anabolic and catabolic reaction?

Answer 7

anabolic- building large molecules
catabolic- breaking large molecules into smaller ones

Question 8

what is phosphorylation?

Answer 8

when an inorganic phosphate is added to another compound which can make it more reactive

Question 9

explain five properties that make water important for organisms

Answer 9

1.is a metabolite in chemical processes eg, hydrolysis
2. a solvent so it allows transport of substances
3. high specific heat capacity so buffers changes in temperature eg, minimises fluctuations in temperature inside cells
4. large latent heat of vaporisation so provides a cooling effect through evaporation (useful in homeostasis)
5. cohesion between molecules so produces surface tension supporting small organisms

Question 10

explain the property of water that helps to prevent temp increase in a cell

Answer 10

1. high specific heat capacity so takes a lot of energy to change temp
2. buffers changes in temp

Question 11

explain two properties of water and their importance in the cytoplasm

Answer 11

1. polar molecule, acts as a solvent
2. reactive, takes place is hydrolysis and condensation

Question 12

how do hydrogen ions affect pH?

Answer 12

more H+ ions=lower pH which affects enzyme controlled reactions

Question 13

describe the roles of iron ions in cells

Answer 13

the Fe2+ ions in haemoglobin bind with oxygen and become Fe3+ until is released

Question 14

describe the role of sodium ions in cells

Answer 14

1. co transport of glucose into cells
2. because sodium moved out by sodium potassium pump
3. creates a sodium diffusion gradient
4. affects osmosis

Question 15

describe the role of phosphate ions in cells

Answer 15

1. joins nucleotides in phosphodiester bonds
2. ATP energy is stored in the bonds
3. used in phosphorylation
4. hydrophilic part of the phospholipid bilayer