T1: Inorganic Ions

Question 1

hydrogen ions

Answer 1

the concentration of H+ ions is used for calculating pH
(more H+ = lower pH = more acidic)
enzyme controlled reactions are controlled by pH

Question 2

sodium ions

Answer 2

Na+ generates resting and action potentials in neurons
main cation of blood plasma, the level of Na+ regulates water potential of a cell

Question 3

phosphate ions

Answer 3

DNA has a sugar phosphate backbone
bonds between phosphate ions store energy as ATP
DNA, RNA and ATP all contain phosphate groups

Question 4

iron ions

Answer 4

haemoglobin is a large protein that carries oxygen around the body in blood

made of 4 polypeptide chains with a Fe2+ ion in the centre (binds to O2), when oxygen binds turns to Fe3+ temporarily