ph And Enzymes Flashcards
1
Q
Write a method for this experiment.
A
- Heat your water bath to 35 °C.
- Put 2 cm3 of each buffered solution into individual, separate test tubes. Label each tube with the pH of the solution.
- Label 5 test tubes ‘Starch’ and add 4 cm3 of starch solution into each tube.
- Put a thermometer in one of the starch test tubes to monitor the temperature. Leave the thermometer in this tube throughout the experiment.
- Add 10 cm3 of Amylase solution into another test tube. Label the tube ‘amylase’.
- Put all the test tubes into the water bath.
- Allow the solutions to reach 35 °C.
- While the solutions are reaching the required temperature, put one drop of Iodine solution into each depression on your spotting tile. Put a drop of starch solution in the first depression of the tile. This is your ‘zero time’
mixture. You will use this as a comparison of colour for your test buffers. Starch gives a blue-black colour with iodine, and the iodine stays brown if all the starch has broken down to glucose. - When all the tubes have reached 35 °C take one of the tubes of starch from the water bath and add the 2 cm3 of your first pH buffered solution. Stir the mixture with a glass rod.
- Use the pipette to add 2 cm3 of amylase solution to the mixture. Start the stopclock as soon as you add the amylase. Keep stirring the mixture with the glass rod.
- After 10 seconds, remove one drop of the mixture with a glass rod.
- Put this drop on the second depression of your spotting tile.
- Rinse the glass rod with water.
- Every 10 seconds, use the glass rod to remove one drop of the mixture.
Put each drop onto the iodine solution in the next depression on the spotting tile. Remember to rinse the glass rod with water after putting each drop on the spotting tile. - Keep sampling every 10 seconds until the iodine does not change colour
2
Q
Describe the effect that pH has on the shape of an enzyme
A
If an enzyme is not in its ideal pH condition then the enzyme will denature (change shape)
