Investigating the effect of enzyme concentration on the initial rate of reaction
Hydrogen peroxide is broken down into water and oxygen by the enzyme catalyse. Measure how much oxygen is given off with different concentrations of the enzyme. Measure the amount of oxygen given off in the first minute of the reaction. Then divide the volume of oxygen produced by the time, to get the initial rate of reaction. The more oxygen that is given off in the first minute of the reaction, the faster the initial rate of reaction.
Cell Membrane Permeability
Investigate how different conditions affect the permeability of beetroot cell membrane
Beetroot cells contain a coloured pigment that leaks out- the higher the permeability of the membrane, the more pigment leaks out.
- Cut five equal sized pieces of beetroot and rinse them to remove any pigment released during cutting
- Place the five pieces in five different test tubes, each with 5cm3 of water
- Place each test tube in a water bath at a different temperature
- Remove the pieces of beetroot from the tubes, leaving just the coloured liquid
- Use a colorimeter- the higher the absorbance of light, the more pigment released, so the higher the permeability of the membrane