Biology Enzymes

Learning Intentions What are enzymes? Describe the structure of enzymes Types of enzyme reactions Examples of enzymes Effect of Temperature & pH on enzymes

1. What are enzymes? What are enzymes (short video clip) 1. Enzymes are found in all living cells. 2. Enzymes are made of protein. 3. Enzymes are Biological Catalysts 4. Enzymes speed up reactions 5. Enzymes are unchanged by the reaction

2. Structure of Enzymes Build a Play-doh Model Enzyme active site The Substrate is the chemical that the enzyme acts on The Product is the end chemical produced The active site of an enzyme is where the chemical reaction occurs and is said to be “complementary” to the substrate. The enzyme and the substrate shape match each other exactly Enzymes are specific – as only one enzyme acts on only one substrate Build a Play-doh Model

3.Types of Enzyme Reactions Degradation Reaction (“breaking down”) Catalase Hydrogen Peroxide Oxygen + Water Degradation Reaction - Practical Synthesis Reaction (“building up”) Synthesis Reaction - practical Phosphorylase Glucose-1-phosphate Starch

4. Examples of enzymes Substrate Enzyme Product Fats Lipase Fatty Acids & Glycerol Protein Protease Amino Acids Starch Amylase Amylase in action Maltose

5.Types of Enzyme Reactions Enzyme animation

6. Effect of Temperature on Enzymes Optimum Temperature As temperature increases the enzyme activity increases. The temperature that the enzymes works best at is called it’s Optimum Temperature If the temperature is too high, the enzymes active site changes shape. When the enzymes active site has changed shape, the enzyme is said to be denatured, and it will no longer work.

7. Effect of pH on Enzymes Enzymes work best within a range of pH depending on the type of enzyme. The pH that the enzymes works best at is called it’s Optimum pH If the pH is too high, the enzymes active site changes shape (denatured) What is the optimum pH of this enzyme ?

8. Denatured Enzymes Normal Enzyme Active site fits substrate specifically – like a lock and key (they are complementary to each other) Denatured Enzyme Active site has changed shape so it no longer fits substrate specifically – like a lock and key Enzymes Summary Video clip

9 Enzymes & Industry Enzymes in Fruit Juice Enzymes help to get as much juice as possible from the fruit. Enzymes in Detergents Enzymes help to breakdown biological stains on clothes Enzymes in Pharmaceutical Industries Enzymes are used in medicine to treat blood clots and tumours. Enzymes are also used in testing kits e.g. testing for sugar in urine Practical – Pectinase & Fruit Juice

10) Enzymes & Biotechnology Immobilisation Immobilisation is a technique used to trap enzymes or yeast cells so that they can be reused in order to save money. This means products can be continually made. This process is also called Continuous Flow Processing Immobilised enzymes are used in the production of lactose free milk for people who are lactose intolerant Immobilised enzymes are used in glucose testing strips to measure glucose levels in diabetics Practical – Immobilisation