Do Now (on loose-leaf) What is catalase? What does catalase break down? What is the chemical formula that shows this process? (Reactants  Products) An enzyme Hydrogen peroxide (H2O2) 2H2O2 ----> 2H2O + O2 (fix) Review Lab Procedures silently and independently

How Enzymes Work http://highered.mheducation.com/sites/0072495855/student_view0 /chapter2/animation__how_enzymes_work.html

How Enzymes Work Enzymes are proteins Lower the activation energy of a chemical reaction

Enzyme-Substrate Complex The substance (reactant) an enzyme acts on is the substrate Enzyme Joins Substrate

Active Site A restricted region of an enzyme molecule binds to the substrate Binding occurs at the active site LOCK AND KEY Active Site Enzyme Substrate

Enzyme-substrate complex

Catalase Enzyme Lab Catalase: enzyme that breaks down hydrogen peroxide (toxic to our cells) Found in liver cells Chemical formula: 2H2O2 ----> 2H2O + O2

Catalase Lab: Safety Procedures Safety goggles at all times Gloves if you are handling hydrogen peroxide Hair pulled back

Part A 2 mL of hydrogen peroxide into Test Tube 1 Add small piece of liver Observe and record observations After you have recorded observations, pour out hydrogen peroxide 2 mL of hydrogen peroxide into Test Tube 2 Add SAME piece of liver

Part B 2 mL of hydrogen peroxide into Test Tubes 3 & 4 Potato into Test Tube 3 Apple into Test Tube 4 Observe and record observations

Part C Piece of clean liver into Test Tube 5 Cover with distilled water Boil for 5 minutes Pour out water Add 2 mL hydrogen peroxide Observe and record observations

Part D Use the image above to complete Part D of your Lab.

Analysis Questions 1-5

Enzyme-Substrate Complex The substance (reactant) an enzyme acts on is the substrate Enzyme Joins Substrate

Active Site A restricted region of an enzyme molecule binds to the substrate. LOCK AND KEY Active Site Enzyme Substrate

Check Yo’ Self What was the substrate in the lab? Hydrogen peroxide (H2O2) What was the enzyme in the lab? Catalase Explain the chemical reaction that occurred as a result of the enzyme Catalase broke down hydrogen peroxide into oxygen and water

What is the catalyst in this reaction? What was the reactant? (APPLY KNOWLEDGE)

Enzyme + Substrate = Product

Competitive Inhibitor vs. Noncompetitive Inhibitor A competitive inhibitor blocks the active binding site and prevents a reaction Noncompetitive inhibitor attaches the enzyme and changes the shape of the active site