topic 2.4

• What is activation energy?

  The amount of energy needed for a reaction to happen
• What is an active site?

  A specific region on an enzyme where the substrate binds and the reaction takes place.
• what is amylase?

  An enzyme that catalyses the extracellulr breakdown of starch
• What is catalase?

  An enzyme that catalyses the intracellular breakdown of hydrogen peroxide into oxygen and water
• What is a coenzyme?

  A type of cofactor that is bound loosely to an enzyme with weak interactions
• What are cofactors?

  A non-protein molecule that is needed for the effective functioning of an enzyme
• what is a competitive inhibitor?

  a molecule which binds to the active site of an enzyme and prevents the substrate from binding.
• What is Cyanide (CN) ?

  a metabolic poison which acts as an irreversible inhibitor of cytochrome oxidase and hencepreventing respiration.
• What is end product inhibition?

  a mthod of enztme inhibiton where the product of an enzyme controlled reaction can bind to the enzyme and prevent it from working
• what is an enzyme?

  A biological catalyse used to speed up the rate of biochemical reactions without being used up or permanently altered.
• What is the enzyme-product complex?

  The temporary complex formed after the enzyme has catalysed the reaction, but beofre the products have left the active site of the enzyme.
• What is the enzyme-substrate complex?

  The temporary complex formed when the substrate binds to the active site of the enzyme.
• What is an extracellular reaction?

  A reaction that occurs outside of cells
• What is an inactive precursor?

  An inactive form of an enzyme that cannot carry out its function until it is activated.
• What is the induced fit hypothesis?

  A model of enzyme action that describes how once a specfic substrate binds to the active site, the enzyme undergoes subtle conformational changes to fit the substrate better.
• What is an intracellular reaction?

  A reaction that occurs within cells
• What is the lock and key hypothesis?

  A model of enzyme action that describes how the enzyme will only fit a substrate that has the correct compelmentary shape to the active site.
• What is meant by metabolism?

  The sum of all chemical reactions taking place within a cell.
• What is a non-competitive inhibitor?

  An inhibitor which binds to a different part of an enzyme known as the allosteric site and prevents the enzyme from functioning
• What is a prosthetic group?

  A type of cofactor that is bound tightly to an enzyme with strong interactions.
• What is substrate specifity ?

  The ability of an enzyme to catalyse only a specific reaction or set of reactions which have substrates complementary to the active site of the enzyme.
• What is meant by the temperature coefficient (Q10) ?

  A method of calculatin an increase in reaction rate after a 10 degree C increase
• how to calculate the temperature coefficient?

  Q10 = R2/R1
• What is trypsin?

  An enzyme that catalyses the extracellular breakdown of proteins.