Enzyme Structure and Function

• Enzyme -molecules that help in speeding up the chemical reactions that occur in cells.
• Primary Structure -refers to the specific sequence of amino acids in a polypeptide chain
• Secondary Structure -refers to the protein's folding pattern
• Tertiary Structure -refers to how the polypeptides form the shape of the molecule
• Quaternary Structure -refers to the subunits of the protein
• Binding site -amino acid residues that function to bind or accommodate the substrate molecule
• Catalytic site -amino acid residues in active site that serve to speed up or catalyse the reactions once binding has occured
• Substrate -a molecule that the reactions of which are catalyzed by enzymes

  Each enzyme is specific to substrate
• Products -once the enzyme and substrate bound to each other and the reaction has occured, a _ is then produced by the enzyme
• Lock-and-Key -the specific shape between the active site and the substrate allows only that type of binding to occur between these two molecules
• Induced Fit -interaction is initially weak but the bond strengthens as the active site is modifies
• Catalysis -is the speeding up of reaction rates that are specific to the type of substrate and enzyme involved
• The lowering of the activation energy is possible because enzymes modify the reactants into a state known as the transition state
• Enzyme' roles in the Body:

  Digestion

  Cell Division

  Nervous Function

  DNA replication
• Factors Affecting Enzyme Activity

  Temperature

  pH

  Substrate Concentration

  Enzyme Concentration
• Temperature

  Low Temperature:

  Slow movement of molecules means less collisions

  Reaction rate id relatively slow

  High Temperature:

  High reaction rate

  Excessively high temperatures lead to denaturation
• The reaction rate reaches its peak at the optimum temperature
• Pepsin works in relatively acidic condition, while trypsin functions at basic pH
• The highest reaction rates be achieved when all the enzyme have available substrates for binding and catalysis
• Substrate Concentration

  The highest reaction rates can be achieved when all the enzymes have available substrates for binding and catalysis
• pH Level

  Unfavorable _ alterations may result in a decrease in enzyme activity, with the more extreme changes in _ rendering the enzyme dysfunctional.
• Enzyme Concentration

  A higher _ can ensure that there are more catalysts available to speed up a particular chemical reaction