1.8 Inorganic ions

Question 1

Inorganic ions occur in solution in…

Answer 1

Inorganic ions occur in solution in the cytoplasm and body fluids of organisms, some in high concentrations and others in very low concentrations.

Question 2

Each type of ion has a specific role, depending on its properties. Hydrogen ions…

Answer 2

Affect pH. You should be able to calculate the pH of a solution given its hydrogen ion concentration, using the formula: pH = −log10 [H+]. In both respiration and photosynthesis, ATP production occurs when protons diffuse down an electrochemical gradient through molecules of the enzyme ATP synthase, embedded in the membranes of cellular organelles.

Question 3

Each type of ion has a specific role, depending on its properties. Iron ions…

Answer 3

iron ions are a component of haemoglobin. Haemoglobin is a protein with a quaternary structure. Each of its polypeptides is associated with a haem group, which contains an iron ion. Each iron ion can combine with a single oxygen molecule.

Question 4

Each type of ion has a specific role, depending on its properties. Sodium ions…

Answer 4

Sodium ions are involved in the co-transport of glucose and amino acids in the mammalian ileum, in the establishment of a resting potential and generation of an action potential in neurones, and in the reabsorption of water in the loop of Henle.

Question 5

Each type of ion has a specific role, depending on its properties. Phosphate ions…

Answer 5

Phosphate ions are components of DNA, RNA and of ATP. Phosphorylation of molecules makes them more reactive, and phosphorylation can change the tertiary structure of proteins.