1B: inorganic ions

Question 1

what is an ion? what is one w positive/negative charge called?

Answer 1

-atom with an electric charge
-positive: cation, negative: anion

Question 2

what is an inorganic ion?

Answer 2

-doesnt contain carbon
-although some exceptions

Question 3

where are inorganic ions found?

Answer 3

-in solution, in cytoplasm of cells + in bodily fluids of organisms
-each has a specific role depending on its properties, role determines whether its found in high/low concentrations

Question 4

what are the 4 main inorganic ions?

Answer 4

-hydrogen
-iron
-sodium
-phosphate

Question 5

iron ions?

Answer 5

-important part of haemoglobin- large protein that carries oxygen around body in red blood cells
-4 different polypeptide chains each with iron Fe3+ in centre
-Fe2+ binds to oxygen in haemoglobin
-when oxygen is bound to Fe2+ temporarily becomes Fe3+ ion until oxygen released

Question 6

hydrogen ions?

Answer 6

-determine pH
-pH calculated based on concentration of H+ ions in environment
-more H+ ions present the lower the pH (more acidic)
-enzyme controlled reactions all affected by pH

Question 7

sodium ions?

Answer 7

-help transport glucose + amino acids across membranes
-glucose/amino acid can be transported into a cell across cell-surface membrane alongside sodium ions -> co-transport

Question 8

phosphate ions?

Answer 8

-essential for ATP + DNA
-when phosphate ion attached to another molecule = ‘phosphate group’
-DNA, RNA, ATP all contain phosphate groups
-bonds between phosphate groups that store energy in ATP
-phosphate groups in DNA + RNA allow nucleotides to join to form polynucleotides