amino acids

• describe the structure of an amino acid

  every amino acid has an amine group (H2N), a residual (R) and a carboxyl group (COOH)
• what are proteins made of

  all proteins are made from 20 amino acids that occur naturally in the world

  the residual group differs for each amino acid group

  bonded by peptide bonds formed via condensation reactions

  dipeptides are formed by the condensation of 2 amino acids

  polypeptides are formed by the condensation more than 2 amino acids
• the residual group for glycine

  H
• the residual group for alanine

  CH2
• the residual group for asphatate

  CH2

  |

  COO
• describe the primary structure of proteins 


  the sequence of amino acids determined by DNA

  polypeptide chains are formed through a series of condensation reactions known as polymerisation
• describe the secondary structure of a protein

  the folding of a protein int alpha helix and beta pleated sheets using hydrogen bonds
• describe the tertiary structure of a protein

  further folding of the secondary structure

  bonds formed may include

  h- bonds- numerous but easily broken

  ionic bonds- formed between and carboxyl group and amino group that are not involved in forming peptide bonds. They are weaker than disulphide bonds and are easily broken by a change in pH

  disulphide bonds- fairly strong and therefore not easily broken
• describe the quaternary structure of a protein

  multiple polypeptide join together to form the final protein