Digestion What do we know now? Enzyme action

Factors that affect Enzyme activity 1 minute to list any factor that you think could change how fast an enzyme can work (hint… think kinetic energy / acidity / amounts)

To find out how enzymes are affected by temperature Investigation To find out how enzymes are affected by temperature What could we change?

How does temperature affect the action of Amylase on Starch? What will we change? What will we keep the same? What will we measure?

To help make this more reliable we will:

We are investigating.. How enzymes are affected by temperature Our question is.. How does temperature affect the action of amylase on starch? Complete the planning sheet (using all the ideas we have talked about)

Method Iodine into wells on tile 5ml starch in syringe Wash outside Add 1ml amylase to syringe Quickly add air bubble and mix Start clock Place in water bath After 30 seconds - remove, blot dry, add 1 drop of mixture to iodine Replace syringe in water bath. Repeat iodine test every minute Record time taken for iodine to stay yellow – in minutes Wash out syringe and repeat

Own Results My temperature was.. Repeat 1 Repeat 2 Repeat 3 Repeat 4 Time taken for iodine to stay YELLOW/MINS Start temperature.. End temperature.. My average time was:______ Enter this on the spreadsheet

Results spreadsheet

Time / seconds for each repeat Temperature (°C) Time / seconds for each repeat 1 2 3 4 5 6 Mean 20 195 30 125 40 26 50 70 60 150 80 Did not digest

Graph to show how temperature affects the action of amylase on starch Average time for starch to digest / seconds Temperature / oC

Rules for drawing a good graph Use a ruler and sharp pencil Use a linear scale (even intervals between numbers) X axis Independent variable (the factor you change) Y axis Dependent variable (factor you measure) Label axes and don’t forget to add /units Sharp, neat cross for each point Smooth continuous curve to join points Add a title