Enzymes

• what are enzymes?

  biological Catalysts produced by living things
• how can you make a reaction happen more quickly?

  raising the temperature
• what type of reaction do living things have thousands off?

  chemical reactions
• What do enzymes act as?

  biological catalysts
• What do enzymes speed up?

  useful chemical reactions in the body
• what is a catalyst?

  A substance which increases the speed of reaction without being changed in the reaction
• enzymes are large what?

  proteins
• what are all proteins made up off?

  chains of amino acids
• what kind off shape are enzymes?

  unique shapes
• why do enzymes have special shapes?

  so they can catalyse reactions
• chemical reactions usually involve things being what?

  split up or joined together
• what does every enzyme have?

  an active site with a unique shape that fits onto substance involved in reaction
• how many reactions do enzymes catalyse?

  one
• why do enzymes only catalyse one reaction?

  As the substrate has to fit the active site and if it doesnt then the reaction wont be catalysed
• explain the induced model of enzyme action.

  active site changes shape as substrate binds to it to get a tighter fit
• explain the lock and key model.

  scientists thought that the substrate had to fit perfectly into the active site. Like a key fits perfectly into a lock.
• what is more realistic? The lock and key model or the induced fit model?

  induced fit model
• what do enzymes need?

  right temperature and ph
• what does changing the temperature do to an enzyme catalysed reaction?

  rate changes
• what does a higher temperature do to rate of reaction?

  increases it
• what happens if the reaction gets too hot?

  bonds holding enzyme together break and enzymes active site changes shape so substrate wont fit it anymre and the enzyme denatures
• What do all enzymes have?

  optimum temperature
• what happens if the PH in the reaction is too high or low?

  Ph interferes with the bonds holding the enzyme together which changes shape of active site and denatures the enzyme.
• what is pepsin?

  An enzyme used to break down proteins in the stomach
• what are enzymes optimum PH usually?

  7
• what PH does pepsin work best at?

  2
• what kind off conditions are pepsin well suited to?

  acidic conditions