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 quaternary structure (4°) in a protein

  Several polypeptide chains which are joined by; ionic bonds , hydrogen bonds and disulfide bridges

  These are insoluble due to non-polar R groups
• Draw the structure of an amino acid

  
• What bonds do proteins have between peptide chains ?

  Peptide bonds
• What's the equation for working out the number of peptide bonds?

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

  They all have an amino and carboxyl group, an R group

  Contain; N, C, H, O

  They have different versions 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 carboxyl 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 temperature in proteins?

  Hydrogen (and ionic bonds)
• Which bonds are broken by pH fluctuation in proteins?

  Ionic bonds
• What are the two forms of the secondary structures of proteins?

  Alpha helix and beta pleated sheet