3.1.8 ions

Question 1

what is the role of hydrogen ions?

Answer 1

concentration depends on pH of solutions - protein shape and function.

Question 2

what is the role of iron ions?

Answer 2

component of harm group in haemoglobin - binding site of oxygen.

Question 3

what is the role of sodium ions?

Answer 3

1) co-transport of glucose and amino acids in ileum and proximal convoluted tubule.
2) depolarisation and generation of action potentials in neurones.

Question 4

what is the role of phosphate ions?

Answer 4

1) component of nucleotides.
2) component of ATP (hydrolysis of 3rd Pi to phosphorylate other compounds).

Question 5

what is the role of calcium ions?

Answer 5

1) initiate exocytosis of neurotransmitters at synapses.
2) bind to tropomycoin and expose mycein binding sites on actin to enable muscle contraction.

Question 6

what is the role of potassium ions?

Answer 6

repolarisation of neurones.