1. Most enzymes are proteins that function to lower the activation energy of a chemical reaction Enzymes are very specific as to the reaction they catalyze Enzymes act in catabolism and anabolism Enzymes are involved in a large majority of reactions that take place within cells ENZYMES

2. Enzymes - Digestion

3. Use of enzymes Enzymes can be taken out of organisms, purified and then used in science and industry. One common use in the home is in biological washing powders. These contain amylase, lipases and proteases and break down any stains that contain carbohydrate, fat and protein. They therefore digest “biological” stains from the clothes. Since enzymes work at a low temperature this saves electricity and makes them good for delicate fabrics. Other uses of enzymes Enzymes are used in many industrial processes. Here are some examples of enzymes and their uses. Amylases - used in textile and paper production Ficin - used in photography processes Pepsin - used in the pharmaceutical industry Bacterial proteases - used in making leather, textiles and in laundry Catalase - used in rubber production Taq polymerase - used in amplifying DNA found at crime scenes

4. Enzymes in food Many enzymes are used in the preparation of many different foods. amylases which are present in yeast are used in brewing and baking to convert sugars into alcohol and carbon dioxide. Proteases are used in tenderising meat. Rennin is essential to create cheese. Invertase is used to make some soft centred sweets such as thin chocolate covered mints. A thick, almost solid, paste of sucrose and a little water containing invertase is covered in chocolate and left at room temperature for a few days. The sucrose is converted into a mixture of glucose and fructose which creates a soft centre to the chocolate..

5. Other uses of enzymes Enzymes are used in many industrial processes. Here are some examples of enzymes and their uses. Amylases - used in textile and paper production Ficin - used in photography processes Pepsin - used in the pharmaceutical industry Bacterial proteases - used in making leather, textiles and in laundry Catalase - used in rubber production Taq polymerase - used in amplifying DNA found at crime scenes

7. Some definitions: Enzyme: a biological catalyst, almost all enzymes are proteins (globular) Eg. Lactase breaks down the sugar lactose Substrate: a reactant in an enzymatic reaction Eg. Lactose is the substrate for lactase Active site: place on enzyme that substrate binds to

8. Sucrose (disaccharide) to monomers glucose and fructose catalyzed by the enzyme sucrase Text ref: page 43

9. The Induced Fit Hypothesis Text reference: page 43

10. Intermolecular Forces and the Enzyme-Substrate Complex Enzyme and substrate from complex through H- bonding and interactions between charged regions

11. Allosteric Inhibition allosteric inhibition slows down the pathway, reducing the rate of end product formation. An example of of negative feedback...

12. substrate competitive inhibitor enzyme active site A competitive inhibitor is any compound which closely resembles the chemical structure and molecular geometry of the substrate. The inhibitor competes for the same active site as the substrate molecule. Competitive Inhibition

13. A substance that competes directly with the normal substrate for an enzyme’s binding site is known as a competitive inhibitor. The inhibitor resembles the normal substrate so that it binds to the active site thus inhibiting the normal substrate from binding

14. Electron Micrograph of HIV virus Schematic of HIV

15. Pg 54 # 5-11, 14