Investigating Enzymes

Question 1

effect of temperature on enzymes experiment

Answer 1

• (any enzyme can be used to investigate the effect of temperature)
• amylase digests starch - mix 10cm3 of 10% starch suspension and 5cm3 of 5% amylase in a boiling tube and heat in a water bath
• every minute (from the point mixing occurs) take one drop of this mixture and add it to one drop of iodine solution in the spotting tile
• when digestion is complete and no starch is present, iodine solution will stay orange (rather than turning blue/black
• repeat this using water baths of different temperatures

Question 2

effect of pH on enzymes?

Answer 2

• (you can use any enzyme to investigate the effect of pH)
• potato contains the enzyme catalase, which breaks down hydrogen peroxide, forming water and oxygen gas
• add 10 potato disks (1m thick, cut with a cork borer) to 20cm3 catalase and measure the volume of gas produced in 5 minutes
• the pH can be altered by adding different volumes of a weak alkali or a weak acid - use universal indicator paper to determine the pH of the solution each time