A student investigated the effect of temperature on the activity of amylase. The figure below shows the apparatus used. This is the method used. 1. Set up the apparatus as shown in the figure above. 2. After 5 minutes, pour the starch solution into the amylase solution and mix. 3. Remove one drop of the starch-amylase mixture and place onto a spotting tile. 4. Immediately add two drops of iodine solution to the starch-amylase mixture on the spotting tile. 5. Record the colour of the iodine solution added to the starch-amylase mixture. 6. Repeat steps 3 to 5 every minute until the iodine solution stays yellow-brown. 7. Repeat steps 1 to 6 using water at different temperatures.- 7016

One thought on “A student investigated the effect of temperature on the activity of amylase. The figure below shows the apparatus used. This is the method used. 1. Set up the apparatus as shown in the figure above. 2. After 5 minutes, pour the starch solution into the amylase solution and mix. 3. Remove one drop of the starch-amylase mixture and place onto a spotting tile. 4. Immediately add two drops of iodine solution to the starch-amylase mixture on the spotting tile. 5. Record the colour of the iodine solution added to the starch-amylase mixture. 6. Repeat steps 3 to 5 every minute until the iodine solution stays yellow-brown. 7. Repeat steps 1 to 6 using water at different temperatures.- 7016”

1. The iodine did not turn yellow-brown because the starch is still present and has not been broken down.
   At 5 °C, the amylase and starch molecules have low kinetic energy, so there are fewer collisions between them. This means fewer enzyme-substrate complexes are formed.
   At 80 °C, the amylase enzyme is denatured, which means its active site changes shape. Because of this, the starch can no longer fit into the active site, so it cannot be broken down.

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