Year 12 Revision Topic 2: Molecular Biology 2.1 Molecules to metabolism 2.2 Water 2.3 Carbohydrates and lipids 2.4 Proteins 2.5 Enzymes 2.6 Structure of DNA and RNA 2.7 DNA replication, transcription and translation 2.8 Cell respiration 2.9 Photosynthesis

2.1 Molecules to metabolism Carbon compounds Drawing molecules Metabolism

1. Carbon Compounds Carbon Compound Characteristics Carbohydrate Lipid Protein Nucleic Acid

1. Carbon Compounds Carbon Compound Characteristics Carbohydrate Composed of carbon, hydrogen and oxygen. 2H:10 Lipid Insoluble in water. Steroids, fatty acids and triglycerides. Protein One or more chains of amino acids. Contain carbon, hydrogen, oxygen and nitrogen. Nucleic Acid Chains of nucleotides. Contain carbon, hydrogen, oxygen, nitrogen and phosphorous. RNA and DNA.

2. Drawing molecules Glucose

2. Drawing molecules 2. Ribose

2. Drawing molecules 3. A saturated fatty acid

2. Drawing molecules 4. A generalized amino acid

All enzyme catalyzed reactions in a cell or organism 3. Metabolism Metabolism Anabolism Catabolism Synthesis of complex molecules from simpler molecules. Require energy. Condensation. Break down of complex molecules into simpler molecules. Releases energy. Hydrolysis. All enzyme catalyzed reactions in a cell or organism

All enzyme catalyzed reactions in a cell or organism 3. Metabolism Metabolism Anabolism Catabolism All enzyme catalyzed reactions in a cell or organism Synthesis of complex molecules from simpler molecules. Require energy. Condensation. Break down of complex molecules into simpler molecules. Releases energy. Hydrolysis.

2.2 Water Hydrogen Bonding Properties

1. Hydrogen Bonding Hydrogen bonds are within the water molecule Hydrogen bonds are between water molecules

Hydrogen bonds are between water molecules 1. Hydrogen Bonding Hydrogen bonds are between water molecules

2. Properties Property Definition Use Cohesion Adhesion High specific heat capacity High latent heat of vaporization High boiling point Solvent

Property Definition Use Cohesion Water binding with water causes them to stick together Water transport in plants Surface tension Adhesion Water binding with other polar molecules causes them to stick together Water retention in plants High specific heat capacity High temperature needed to break H bonds. Energy needed to raise temperature of water is high. Thermally stable habitat High latent heat of vaporization High amounts of energy needed to evaporate water. Energy absorbed. Good evaporative coolant. Sweating. High boiling point Highest temperature in a liquid state is high. Large temperature range for habitats on earth (0-100 degrees) Solvent Polar properties = substances can dissolve. Transport of nutrients in blood Transport of nutrients in plants

2.3 Carbohydrates and Lipids Condensation reactions Polysaccharides Lipids Body mass index Fatty acids

1. Condensation Reactions monosaccharides 🡪 disaccharides 🡪 polysaccharides

1. Condensation Reactions monosaccharides 🡪 disaccharides 🡪 polysaccharides

2. Polysaccharides Cellulose Starch Glycogen Linking of alpha glucose molecules. Unbranched. Compact and good for storage. Insoluble. Linking of alpha glucose molecules with many branches. Insoluble. Linking of beta glucose molecules. Forms chains with H bonds between.

2. Polysaccharides Cellulose Starch Glycogen Linking of beta glucose molecules. Forms chains with H bonds between. Linking of alpha glucose molecules. Unbranched. Compact and good for storage. Insoluble. Linking of alpha glucose molecules with many branches. Insoluble.

3. Condensation Reactions Three fatty acids and one glycerol

4. BMI BMI =

4. BMI Mass (kg) (Height (m))2

4. BMI 60 kg, 1.75m 80 kg, 1m 50kg, 1.4m

5. Fatty Acids Saturated Monounsaturated Polyunsaturated Cis unsaturated Trans unsaturated