Factors which Affect the Activity of the Enzyme Catalase
background information about concepts involved in the lab,
statement of purpose of the lab
identification of independent and dependent variables.
A hypothesis is often not necessary or appropriate.
Enzymes are proteins that speed up chemical reactions in cells. They break down molecules called substrates. Each enzyme has only one substrate that it breaks down. Enzymes are produced in the cells of the body and affect the rate of almost all the chemical reactions which take place in living organisms. The rate of enzyme activity is influenced by temperature, pH, and the presence of inhibitors.
Catalase is an enzyme which is produced by every cell to break down hydrogen peroxide.
Hydrogen peroxide is a waste product of cellular activity that is poisonous to cells. Catalase speeds up the decomposition of hydrogen peroxide into harmless water and oxygen gas.
The purpose of this lab was to determine whether an inhibitor affects the rate of activity for the enzyme catalase. Since catalase speeds up the production of oxygen gas, the rate of enzyme activity can be measured as the height of the column of oxygen gas bubbles produced in a test tube. If copper sulfate inhibits the action of catalase, then it will slow down the reaction between the catalase enzyme in chicken liver and hydrogen peroxide. The independent variable in this lab is the addition of copper sulfate to one test tube and the dependent variable is the amount of oxygen gas produced (measured as the height of gas bubbles).
Step by step procedure
Procedure for setting up a control
Identification of the contol
1. Take 2 disposable test tubes and mark them both 1.5 cm from the bottom.
2. Label the tubes respectively with the numbers 1 and 2.
3. Fill both tubes with hydrogen peroxide up to the mark.
4. Add 10 drops of water to test tube 1. (This will