Enzymes & pH
This practical lesson covers:
- The effect of pH on the rate of reaction of amylase enzyme.
Investigating the effect of pH on the rate of reaction of amylase enzyme.
Aim:
To investigate the effect of pH on the rate of reaction of amylase enzyme.
Background information:
The activity of biological catalysts (enzymes) are affected by pH. This practical explores how different pH levels affect the activity of amylase, an enzyme that breaks down starch into sugars. Using buffer solutions to alter pH, you will measure the rate of starch breakdown by observing changes in the colour of an iodine solution.
Variables:
- Independent variable - pH of the buffer solution.
- Dependent variable - Rate of starch breakdown.
- Control variables - Temperature of the reaction, concentration of amylase, concentration of starch, volume of solutions.
What is the purpose of this experiment?
to investigate the effect of substrate on the rate of reaction of amylase enzyme
to investigate the effect of temperature on the rate of reaction of amylase enzyme
to investigate the effect of pH on the rate of reaction of amylase enzyme
to investigate the effect of concentration on the rate of reaction of amylase enzyme
|
Which equipment is NOT needed for this experiment?
water bath
test tubes
thermometer
microscope
|
What is the function of the iodine solution in this experiment?
to measure the rate of reaction
to indicate the presence of starch
to monitor the pH of the solutions
to measure the temperature of the water bath
|
What is the purpose of labeling the test tubes with the pH of the solution?
to measure the rate of reaction
to monitor the temperature of the starch solution
to identify the amylase solution
to ensure the correct pH is added to the starch solution
|
What is the role of the glass rod in this experiment?
to stir the mixture
to indicate the presence of starch
to measure the temperature of the water bath
to measure the pH of the solutions
|
When should the stopwatch be started in this experiment?
as soon as the starch solution is added to the mixture
as soon as the amylase solution is added to the mixture
after 10 seconds of adding the amylase solution
after 10 seconds of stirring the mixture
|
What is the purpose of rinsing the glass rod with water?
to measure the temperature of the water bath
to measure the pH of the solutions
to clean the glass rod
to prevent contamination of the solutions
|
When should the sampling be stopped in this experiment?
when the pH is stable
when the temperature reaches 35°C
after 10 minutes
when the iodine changes colour
|