enzymes

• what are enzymes?


  proteins that catalyse chemical reactions
• whats an enzymes active site?

  the part of an enzyme that the substrate binds with
• why do enzymes only catalyse in specific reactions?

  an enzymes active site is a specific shape so only certain substrates can fit into it causing them to only catalyse specific reactions
• describe the lock and key model of enzyme action?

  only a substrate that exactly fits in a enzyme active site can bind to the enzyme so once that happens the enzyme catalyses the reaction
• what does it mean when an enzyme is denatured ?

  its active site has changed
• how does chaining temperature affect the rate of an enzyme catalysed reaction?

  as temp increases the rate of reaction increases but if it gets too high the enzyme becomes denatured
• enzymes have an optimum temperature and ph what does this mean?


  the temp and ph at which enzymes works best
• 2 things that causes enzymes to denature?

  high temperature and a ph value that to high or low
• how can the effects of ph on amylase activity b investigated?

  comparing how long it takes amylase to fully break down a sample of starch solution at different ph levels
• breif method for inestigating the effect of ph on amylase activity ?

  1. put a drop of iodine solution in each well of a spotting tile
  2. add 2cm of starch solution and 2cm of ph 5 buffer solution to a test tube in a water bath at 35 degree
  3. after 10 minutes stir in 2cm of amylase soultion and start timing
  4. take a drop from test tube every 20 seconds and it in a well then repeat untill the iodine solution stays orangey and record the time passed
  5. repeat experiment with a range of ph buffer solutions