Strand1: SA1, SA2, SA3
Marks: /12 (Part A) + /18 (Part B) = /30
|There are many different reactions that are happening in our bodies all the time. There are reactions that build up molecules, | |synthesis/anabolic reactions, as well as reactions that break down molecules, catabolic reactions. Together the sum of all anabolic and | |catabolic reactions in our bodies makes up our metabolism. | | | |Enzymes are proteins that speed up the rate of reactions that would otherwise happen more slowly. The enzyme is not altered by the | |reaction and so has the ability to work again and again. You have hundreds of different enzymes in each of your cells that perform | |hundreds of different functions; however each enzyme is specific for one particular reaction. All enzymes function best at a specific | |temperature and pH, we call this its ‘optimal’ temperature and pH. | | | |In this practical, you will study an enzyme that is found in the cells of many living tissues called catalase (KAT-uh-LAYSS). It speeds | |up a reaction which breaks down hydrogen peroxide, a potentially toxic chemical, into 2 harmless substances, namely, water and oxygen. | | | |This chemical reaction is written as follows: 2H2O2 → 2H2O + O2 | | | |You will be looking specifically at the catalase found in chicken liver and conduct an investigation on the effect of temperature on its | |activity. |
• Work in groups of 2 or 3.
• Follow the practical procedure (Part A) and then the investigation (Part B) and finally answer the questions that follow. • Each group member will need to record all answers as they will be needed to answer the individual questions in the next period. MATERIALS:
|3 X 10ml Graduated cylinders |Electronic scale | |Measuring pipette |Chicken liver at room temperature | |20Vol (6%) Hydrogen peroxide solution |Boiled chicken liver | |Sharp knife (scalpel) |Frozen chicken liver | |Forceps (tweezers) |Stirring rod |
PART A – Practical Procedure: Catalase activity from chicken livers at room temperature on hydrogen peroxide.
AIM: To determine the effect of catalase in chicken livers, at room temperature, on hydrogen peroxide and to test the products from this reaction for the presence of oxygen.
Room Temperature Catalase Reaction Method:
1. Place 1 ml of the 6% hydrogen peroxide solution into a clean 10ml graduated cylinder. 2. Using forceps and sharp knife/scalpel cut 0.1g of chicken liver (this is...