ATP, Water, Inorganic Ions

Question 1

ATP contains

Answer 1

A molecule of ribose, a molecule of adenine and 3 phosphate groups

Question 2

Describe hydrolysis of ATP

Answer 2

ATP can be hydrolysed with the addition of water to break the bond between the 2nd and 3rd phosphate group. This releases energy. Reaction catalysed by ATP hydrolase
ATP + H2O ➡️ADP + Pi

Question 3

Phosphorylation

Answer 3

Phosphate group transferred to other molecules to make them more reactive so they have the activation energy to take part in another reaction

Question 4

ATP is resynthesised by

Answer 4

The condensation of ADP and Pi. The reaction is catalysed by ATP synthase during photosynthesis or respiration

Question 5

Breakdown of ATP

Answer 5

ATP + H2O ➡️ ADP + Pi
Catabolic
Energy released can be used for:
Active transport
Muscle contraction
Maintaining body temp
Synthesis of new molecules
Nerve impulses

Question 6

Formation of ATP

Answer 6

ADP + Pi ➡️ ATP + H2O
Anabolic
Energy to form ATP usually comes from:
Resp
Photosynthesis

Question 7

Advantages of ATP

Answer 7

Instant source of energy in cell.
Energy released in one single step by hydrolysing one bond
Releases energy in small amounts
Inorganic phosphate can be used to phosphorylate other substances

Question 8

Water atoms has

Answer 8

2 hydrogen atoms covalently bonded to an oxygen atom

Question 9

Bonds between water molecules

Answer 9

Weak IF called hydrogen bonds form between slightly positive hydrogen and slightly negatively charged oxygen on another molecule

Question 10

Properties of water
Reactant solvent habitat

Answer 10

Reactant - water needed as reactant for hydrolysis reactions
Solvent - polar molecule so other polar substances can dissolve in it
Habitat - liquid at room temp - aquatic habitats. Ice less dense than liquid water so floats providing a habitat

Question 11

Properties of water
Transport method temp regulator cohesion

Answer 11

Transport method- solvent so molecules and ions can be transported around living things while dissolved in water (eg blood)
Temp regulator - high specific heat capacity, buffering changes in temp. Large amount of energy needed to raise temp so thermostable.
cohesion - water is polar so opposite charges attract to one another

Question 12

transport method
temp regulation

Answer 12

high latent heat of vaporisation, providing a cooling effect with little loss of water through evaporation.

Question 13

ion

Answer 13

atom/molecule in which total num of electrons is not equal to total num of protons, giving the atom a net positive/negative electrical charge

Question 14

phosphate ions as component of DNA and ATP

Answer 14

Bonds between phosphate groups store energy in ATP.
phosphate groups in DNA and RNA allow nucleotides to join up to form the polynucleotides

Question 15

Hydrogen ions and pH

Answer 15

pH is calculated based on conc of H+ in environment. The more H+, the lower the pH.
enzyme controlled reations affected by pH.

Question 16

Iron ions as component of haemoglobin

Answer 16

Haemoglobin made up of 4 different polypeptide chains, each with Fe2+ in centre. Fe2+ binds to O2 in haemoglobin. When O2 is bound, Fe2+ ions become Fe3+ ions until O2 is released.

Question 17

sodium ions in co-transport of glucose and amino acids

Answer 17

a molecule of glucose or an amino acid can be transported into a cell (across plasma membrane) alongside Na+