CCEA Biology - Enzyme & Digestion Flashcards
Effect of temperature on the action of an enzyme: Procedure Explained
Set up water baths at various temperatures (e.g. 0°C, 20°C, 40°C, 60°C and 80°C).
Add starch solution to 5 test tubes.
Add amylase solution to another 5 test tubes.
Place one starch and one amylase test tube into each water bath for 5 minutes - to allow the enzyme and substrate to reach the desired temperature.
Place 1 drop of iodine into each dimple on a spotting tile.
Add the amylase to the starch in the 0°C water bath.
Start the timer.
Every minute remove a sample of the starch-amylase solution and add it to a drop of iodine on the spotting tile.
Repeat step 8 until the iodine no longer changes colour - meaning that there is no starch present, in other words the amylase has broken all starch down.
Repeat steps 6-9 for each of the temperatures.
Record results.
Draw a graph to show the time taken for starch to be digested at different temperatures.
Effect of temperature on the action of an enzyme: Procedure Simplified
Set up water baths at various temperatures
Add starch solution - 5 test tubes.
Add amylase solution - 5 more test tubes.
Place one starch and one amylase test tube into each water bath for 5 minutes.
Place 1 drop of iodine into each dimple on a spotting tile.
Add the amylase to the starch in 0°C water bath.
Start the timer.
Every minute remove a sample of the starch-amylase solution + add to a drop of iodine on the spotting tile.
Repeat step 8 until the iodine no longer changes colour.
Repeat steps 6-9 for each of the temps.
Record results.
Draw a graph - time taken for starch to be digested at different temps.
Effect of temperature on the action of an enzyme: Results
Optimum temperature - amylase will break down starch quickly.
Low temperatures - amylase will break
starch down slowly due to reduced kinetic energy.
High temperatures - amylase will break starch down slowly or not at all due to denaturation of the enzyme’s active site.
Effect of temperature on the action of an enzyme: Controlled variables
- pH
- Same volume and concentration of starch.
- Same volume and concentration of amylase.
