Inorganic Ions Flashcards
The purpose of inorganic ions
Inorganic ions do not contain carbon
Occur in solution (cytoplasm, body fluids)
Some occur in high and very low concentrations
Ion
Ion - an atom that has an electrical charge
An ion that has a +ve charge
cation
An ion that has a -ve charge
anion
Hydrogen ions (H+)
Also called protons
Concentration of H+ in a solution determines the pH (inversely proportional)
The more H+ ions present, the lower the pH (the more acidic the solution)
The fewer H+ ions present, the higher the pH (the more alkaline the solution)
Iron ions (Fe2+/Fe3+)
Essential for transporting oxygen around the body
Fe2+ in Haemoglobin binds to oxygen → forms oxyhaemoglobin
Myoglobin (in muscles) is a similar protein, but is only made up of one polypeptide chain
Iron is also necessary for electron transport in respiration/photosynthesis
Iron ions are an essential component of cytochromes (that are themselves a component of electron transport chains)
Sodium ions (Na+)
Required for the transport of glucose and amino acids across cell-surface membranes (e.g., in the small intestine)
Glucose and amino acid molecules can only enter cells (through carrier proteins) alongside Na+ - this is known as co-transport
Na+ is also required for the transmission of nerve impulses
Phosphate ions (PO43-)
They attach to other molecules → form phosphate groups - essential components of:
DNA - forms part of the DNA nucleotide
RNA - forms part of the RNA nucleotide
ATP - lots of energy is released when the bonds between phosphate groups are hydrolysed
Phospholipids - key part of the phospholipid bilayer, and allows them to be amphipathic
Calcium ions
Essential in the movement of organisms (transmission of nerve impulses from neurone to neurone)
Stimulate muscle contraction
Help to regulate protein channels → affects the permeability of cell membranes
Enzymes are often activated by calcium ions
Calcium ions are also a clotting factor
