Proteins

• The tertiary structure of a protein is stabilized by various types of interactions, including hydrogen bonds, disulfide bonds, and hydrophobic interactions.
• Protein folding involves the formation of secondary structures such as alpha helices and beta sheets, which are held together by hydrogen bonds between amino acid residues.
• Proteins act as enzymes, hormones, antibodies, and structural components.
• The quaternary structure of a protein refers to the arrangement of multiple polypeptide chains or subunits in a protein complex.
• What are the monomers of proteins

  amino acids
• What is the polymer made from amino acids

  Polypeptide
• How do you form a dipeptide

  Condensation reaction between carboxyl group of one amino acid and amine group of another amino acid. Forming a peptide bond, removing a molecule of water
• describe the primary structure of a polypeptide

  Order and sequence of amino acids
• Describe the secondary structure of a polypeptide

  Folding into an alpha helix or beta pleated sheet forming hydrogen bonds
• Describe the tertiary structure of a polypeptide


  Further folding forming a 3D structure, with hydroge, ionic, covalent bonds and disulfide bridges. Determines active site of enzymes
• Describe the quaternary structure of a polypeptide

  Multiple different polypeptides bonded together with prosthetic groups
• What are globular proteins + an example

  Globular proteins are used for chemical reactions and have hydrophilic amino acid on their surfaces making them solvable. haemoglobin is an example. 2 heavy and 2 lights chains with haem groups with Fe+ which binds to oxygen transporting it around the body
• What are fibourous proteins + 2 examples

  Used for structure, parallel polypeptide chains and are insoluble in water, e.g. ketetin for hair and nails and collagen for connective tissue
• Describe the biochemical test for proteins

  Add bieuret reagent

  observe colour change from blue to lilac
• describe the induced fit model

  substrate binds to active site. active site changes shape slightly to become complementary. to form an enzyme substrate complex.
• how does a competitive inhibitor decrease the rate of reaction

  the competitive inhibitor is the same shape as the substrate, so the inhibitor can bind to the active site of the complementary enzyme. stopping the substrate from binding to the active site, decreasing the number of enzyme-substrate complexes formed.
• how does a non-competitive inhibitor reduce the rate of a reaction

  binds to surface of an enzyme which is not the active site(allosteric), causing the enzyme to denature. this means the substrate can no longer bind to the active site as the active site is no longer complementary. so no more enzyme substrate complexes are made.
• what are the 4 factors which affect the rate of reaction

  temperature, pH, conc of substrate and conc of enzyme
• how does temp effect rate of reaction.

  at low temp, particles have little kinetic energy, particles dont have enough energy to collide successfully and react. as temp increases to optimum temp, particles have alot of Ke , more successful collisions more enzyme substrate complexes made.
• how does pH effect rate of reaction

  if pH is not at optimum active will denature breaking the bonds in the tertiary structure, active site is no longer complementary to the substrete, so no enzyme-substrates can be made.
• how does conc of enzyme,substrate effect rate of reaction

  low conc of enzyme/substrate not enough active sites for substrate to bind or vise-versa. increasing conc of E/S ROR increases as more enzyme-substrate complexes are made. high number of E/S means alot of active sites for the substrate to bind to or vise-versa. when Vmax is reached conc is no longer the limiting reactant