cations

• calcium (ca2+) is involved in the transmission of nerve impulses and the release of insulin from the pancreas

  acts as a cofactor for many enzymes
• Sodium (Na+)- important for generating nerve impulses, for muscle contraction and regulating fluid balance in the body
• potassium (K+)- generates nerve impulses, for muscle contraction and regulating fluid balance in the body.

  activates essential enzymes needed for photosynthesis in plant cells
• Hydrogen (H+) - affects PH of substances

  • important for photosynthesis reactions that occur in the thylakoid membranes in chloroplast
• Ammonium (NH4+) - used in fertilisers and absorbed from the soil by plants and important source of nitrogen