There are about 92 naturally occurring elements. Elements are substances made of only one type of atom.Only a small number of elements are used in living organisms.Organic substances predominantly contain carbon, hydrogen and oxygen, with small amounts of nitrogen and phosphorus and sulfur.Metal ions such as sodium, potassium, calcium and iron ions are important for the functioning of organisms.Chloride ions are needed for the movement of water and other functions. Iodine is an essential component of the thyroid hormones thyroxine and triiodothyronine.
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Specification: OCR Biology A (H020), AS-level, 2.1.2 Biological molecules. Topic: Biological Molecules.
More in Biological Molecules
- Bonding
- Ions
- Biological Molecules
- Polymers
- Water
- Hydrogen Bonding and Boiling Point of Water
- Density of Water
- Cohesion, Adhesion and Surface Tension
All 63 lessons in Biological Molecules · All OCR AS-level Biology topics