Alejandra Cossio Martínez
Effect of temperature on enzymes
DESIGN
Aspect 1 - Defining the problem
Investigate the effect of temperature on enzymes, by calculating the amount of gas produced in the reaction at different temperatures.
Variables
- Independent variable: temperature
- Dependant variable: amount of gas produced
- Variables not changed: amount of potato, pH, volume of H2O2, same time, type of potato and preparation of specimen.
Aspect 2 – Controlling variables
- Collect necessary equipment and materials.
- Set up apparatus for the experiment as shown.
- Weigh 2g of minced potato using a scale up 1/100 of a gram.
- Put the potato in the conical flask and add 5cm3 of buffer solution at 70°C. Swirl gently to mix. Temperature must be stable while reaction is taking place.
- Replace the bung in the flask, ensuring that it is at right seal.
- Fill the burette with water and introduce into it the tube that comes from the flask bung. Invert carefully into the beaker that contains water.
- Measure 5cm3 of hydrogen peroxide into the syringe and connect it to the flask. The H202 has to be at the same temperature as the water in the container, if the water is at 70°C, the H2O2 ha to be at 70°C as well.
- Inject the H2O2. Immediately, start counting time with a stopwatch and record measures of the level of water in the burette every 30 seconds.
- Repeat the experiment but now at 60°C, 50°C, 40°C and 30°C.
