3.1.8 Inorganic ions Flashcards
What are the functions of hydorgen atoms ?
● pH is calculated based on the concentration of hydrogen ions (H+
). The more H+
present the lower the pH level and the more acidic the environment is.
● Enzyme-controlled reactions are affected by pH.
What are the functions of Iron ions ?
● Haemoglobin is a large protein that carries oxygen around the body in red blood
cells
● It’s made of four polypeptide chains - each with an iron ion in the centre
● The iron ion is a key component that binds to the oxygen in haemoglobin
● When oxygen is bound, the Fe2+ ion temporarily becomes an Fe3+ ion until oxygen is
released
What is the function calcium ions ?
● As calcium phosphate it provides a hard, strong, insoluble matrix in bones and
teeth in mammals
● Required for blood clotting in mammals
● As calcium pectate in plant cell walls it forms a matrix in which cellulose fibres lie
● Involved in the transmission of action potentials from one neurone to another in
muscle contraction
What is the function of sodium ions ?
● Helps glucose and amino acids cross cell membranes
● A molecule of glucose or an amino acid can be transported into a cell across the
cell-surface membrane alongside sodium ions (Na+
)
● This is known as co-transport
What is the function of potassium ions ?
● Constantly pumped into cells by active transport in exchange for sodium ions
● Important in the transmission of nerve impulses
What is the function of magnesium ions ?
● Forms part of the chlorophyll molecules in plants
● Important for the absorption of light energy to drive the reactions of photosynthesis
What is the function of chloride ions ?
● Moved out of cells lining the lungs and digestive system to provide a low water
potential outside the cell causing water to follow so mucus is not thick and stiff
(failure of this mechanism causes cystic fibrosis)
What is the function of nitrate ions ?
● Used to produce amino acids and proteins from the carbohydrates made in plants
by photosynthesis
What is the function of phosphate ions ?
● Used in production of nucleic acids (DNA and RNA) production of ATP (energy
currency of cells) and phospholipids which are essential in cell membranes