Experiment 3.1: Biological Actions Experiment. Aim: To study how the biological actions respond to changes in temperature.

Here is the completed experiment plan:

EXPERIMENT 3.1: BIOLOGICAL ACTIONS EXPERIMENT

AIM
To study how the biological actions respond to changes in temperature

PROBLEM STATEMENT
What is the effect of temperature on the rate of enzyme activity?

HYPOTHESIS
The rate of enzyme activity will increase with temperature up to an optimum temperature, and then decrease rapidly at higher temperatures due to denaturation.

VARIABLES

• Manipulated variable: Temperature ($\text{°C}$)
• Responding variable: Rate of enzyme activity (e.g., volume of gas produced per unit time)
• Controlled variable: pH, enzyme concentration, substrate concentration, volume of reactants, reaction time

MATERIALS & APPARATUS

• Potato (source of catalase enzyme)
• Hydrogen peroxide solution (substrate)
• Test tubes
• Beakers
• Water baths (to maintain different temperatures)
• Thermometer
• Measuring cylinders
• Stopwatch
• Delivery tube
• Gas syringe or inverted measuring cylinder in a trough of water
• Knife or grater

PROCEDURE

1. Prepare several test tubes, each containing a fixed volume of potato extract (enzyme source).
2. Set up a series of water baths at different temperatures (e.g., $0\text{°C}$, $20\text{°C}$, $40\text{°C}$, $60\text{°C}$, $80\text{°C}$).
3. Place one test tube with potato extract into each water bath and allow it to equilibrate to the specific temperature.
4. Add a fixed volume of hydrogen peroxide solution to each test tube.
5. Immediately connect a delivery tube from the test tube to a gas syringe or an inverted measuring cylinder to collect the oxygen gas produced.
6. Start the stopwatch and record the volume of oxygen gas produced in a fixed time (e.g., 2 minutes) for each temperature.
7. Repeat the experiment for each temperature to ensure reliability.
8. Record all results in a table.