Amino Acids, Peptide Bonds & Protein Structure The Structure and Function of Large Biological Molecules: Ø Most important large molecules found in living things – carbs, lipids, proteins, nucleic acids Ø Macromolecules (carbs, proteins, nucleic acids) are polymers, built from monomers Carbohydrates serve as fuel and building materials – simplest being monosaccharides, then disaccharides (2 mono’s joined w/ covalent bond). Carb macromolecules are polymers being polysaccharides Lipids are one class of large biological molecules that does not include true polymers, not big enough to be macromolecule Mix poorly/ not at all w/ water – hydrophobic – consist mostly of hydrocarbons Proteins count for more than 50% of the mass of most cells – some speed up chemical reactions, others play roles in defense, storage, transport, communication, movement, structure Amino Acids: The Building Blocks of Protein Ø Amino acids all have the same basic structure consisting of: amino group (-NH2), carboxyl group (-COOH), hydrogen atom & variable group, all linked to central � carbon Ø 20 Amino Acids found in the body all w/ diff variables Ø Monomers form polymers called polypeptides Ø Polypeptides fold up making proteins The Amino acid molecules that are used to build proteins have part that is the same among all – the backbone - This is what makes a molecule an amino acid - *Amino acids differ b/c of the VARIABLE (AKA side chain/ R)* - The key to identifying the backbone is looking for a Carbon atom (c) that has both an amino and carboxyl group attached (Will also always have Hydrogen (H) attached as well) – this is called alpha (�) Carbon - The side chain/ variable is indicated by green R