1.4 Proteins

• Describe the tertiary structure (3°) of a protein?

  Chains are folded in a specific 3D shape. Held by hydrogen, ionic and disulphide bonds. The sequence of amino acids decide how chains fold.
• Describe the quatinary structure (4°) in a protein.

  Several polypeptide chains which are joined by; ionic, hydrogen and disulphate bonds. These are insoluble due to non-polar R groups
• What bonds do proteins make?

  Peptide bonds
• What's the equasion for working out the number of poptide bonds?

  number of peptide bonds = number of amino acids - 1
• Give some similarites and differences of amino acids

  They all have an amino and carboxyl group, an R group and contain; N, C, H, O. They have different make ups of the R groups.
• Describe the primary structure (1°) of a protein?

  A sequence of amino acids joined by peptide bonds in a peptide chain.
• Describe the secondary structure (2°) of a protein.

  Held together by weak hydrogen bonds which causes the polypeptide to coil into an alpha-helix or a beta-pleated sheet depending on which glucose molecule is present.
• What parts of an amino acid molecule are removed when two other amino acids join directly to it?

  Either one of the hydrogens on the nitrate group (NH2) and the OH in the carboxy group.
• What two substances are formed when two amino acid molecules join together?

  A dipeptide and water
• What is hydroxylating?

  The addition of an hydroxyl group (OH)
• Which bonds are broken by temprature in proteins?

  Hydrogen or ionic bonds (always say hydrogen if an option)
• Which bonds are broken by acidity in proteins?

  Ionic bonds
• What are the two forms of secondary structures that a protein can fold into?

  Alpha helix or beta pleated sheet
• Draw the structure of an amino acid.

  Amino Acid: