Anions

• Nitrate (NO3-) - absorbed from soil by plants, important source of nitrogen
• Hydrogen carbonate (HCO3-)- Acts as a buffer which helps maintain the PH of blood
• chloride (Cl-) - involved in chloride shift which helps maintain PH of blood during gas exchange.

  • acts as cofactor for the enzyme amylase
  • involved in some nerve impulses
• Phosphate (PO3- 4) - Photosynthesis and respiration reactions.

  needed for synthesis of many biological molecules, such as nucleotides, phospholipids, calcium phosphate.
• Hydroxide (OH-) - Affects PH of substances (more OH- Ions than H+ in solution creates alkali)