2. 3.1.1 Frequently elements in living things

3. 1.Sulphur (amino acids) 2.Calcium Bones / Teeth 3.Iron haemoglobin (animal) and in the cytochrome proteins involved in eˉ transport in animals & plants. 4.Sodium nerve impulse 5.Phosphorus cell membrane structures & nucleotides. 3.1.2 Other elements in living things

4. Water is a Polar Molecule has oppositely charged ends A hydrogen bond is a type of intermolecular force that forms when a hydrogen in one polar molecule is attracted to the slightly negative atom of another polar molecule. 3.1.4 Water Structure: H 2 O

5. 3.1.5 Properties of water The hydrogen bonding between molecules leads to additional properties in water. The three of the more important properties for biological systems include: SOLVENT PROPERTIES COHESIVE PROPERTIES THERMAL PROPERTIES

6. 3.1.5 Properties of water and its uses in living organisms…