Inorganic Ions

Question 1

Where do they occur?

Answer 1

Occur in solution in the cytoplasm and body fluids of organisms, some in high concentrations and others in very low concentrations

Question 2

Role of Hydrogen Ions (pH)

Answer 2

Hydrogen ions are also important for maintaining the low pH of the gastric juices within the stomach which is important for digestion

Question 3

Role of Iron Ions (Haemoglobin)

Answer 3

Iron ions are essential as they can bind oxygen

Question 4

Role of Sodium Ions (Co-Transport of glucose & amino acids)

Answer 4

First, Na+ is actively transported out of the epithelial cells that line the villi

The Na+ concentration inside the epithelial cells is now lower than the Na+ concentration in the lumen of the small intestine

Na+ now re-enters the cells (moving down the concentration gradient) through co-transport proteins on the surface membrane of the epithelial cells, allowing glucose and amino acids to enter at the same time

Question 5

Role of Phosphate Ions (components of DNA and of ATP)

Answer 5

Attaches to other molecules to form phosphate groups

The phosphate groups allow individual nucleotides to join up (to form polynucleotides)