1. BIOCHEMISTRY

2. PROTEINS Natural polymers C,H,O,N,(S) Monomer is Amino Acids Growth Repair Hormones Enzymes Antibodies Energy Source

3. PROTEINS 15% of our bodies Composed of 20 amino acids 10 we cannot synthesise and store (essential amino acids) We get them from food A Complete Protein contains all 10 (eg Casein)

4. 2-amino acids Contain carboxyl group and amine (amino) group Colourless Crystalline solids Exist as Zwitterions Therfore high m.p. Soluble in water Amphoteric

5. Zwitterions

6. Lysine Basic amino acid

7. Aspartic Acid Acidic amino acid

8. Amino Acids Amphoteric nature makes it possible to act as buffers

9. Condensation Reaction

10. PRIMARY STRUCTURE The sequence of amino acids 3 letter codes used A tripeptide would have 3 amino acids in sequence

11. Secondary Structure Manner in which protein folds Intramoleculer hydrogen bonding important Between O on carbonyl group and H on amine Alpha-helix Beta-pleated sheets

12. Tertiary Structure Overall 3D shape Covalent bonding (eg disulphide bridges) H-bonding Salt bridges (electrostatic attraction) Affect of R group (eg polarity, hydrophobic interactions)

13. Quarternary Structure How subunits join together Haemoglobin

14. Denaturing Heat Ionising radiation Strong acids, bases Concentrated salt solutions Organic solvents Detergents

15. To Do Read pages 324 to 328 Try questions on proteins on page 359

16. Analysis of Proteins Chromatography Hydrolysis (strong acid at 110 °C for several hours) Amino acids seperated

17. Rf Values

18. Electrophoresis Seperation based on electric charge Hydrolysis Each amino acid has different isoelectronic point (pH at which positive and negative ions are balanced) Therefore can be seperated using electrophoresis

19. Major Functions in the Body Structural Biological Catalysts Hormones Antibodies Transport Energy