Transcript Enzymes
Word of the day • Catalyst: – A substance that increases the speed of a chemical reaction AND lowers the amount of energy needed Agenda Latin and Greek Quiz Enzyme Notes Enzyme Study Tool Review • There are four macromolecules – – – – Carbohydrates Lipids Nucleic acids Proteins • Monomer: amino acids • Polymer: polypeptide chains Let’s study one protein: Enzymes What do Enzymes do? • Our body makes many enzymes • Enzymes are specialized proteins that breakdown or combine molecules into things our cells need Catalysts Catalysts: decrease (lowers) the amount of energy needed to start a reaction (activation energy). Enzyme = catalyst Each enzyme is specific to a reaction Ex: Lipase, Protease, Amylase, Lactase, Sucrase, Catalase (Think of a Lock & Key) Enzyme Animation • http://highered.mheducation.com/sites/0072 495855/student_view0/chapter2/animation_ _how_enzymes_work.html In our lab toothpickase… • What represented the enzyme? • What represented the substrate? • What represented the product? Induced Fit Model • The active site on the enzyme is temporarily reshaped each time the molecules bind Like a lock and a key – that you have to jiggle How do Enzymes Work? 1. A substrate(s) fits into a active site on the enzyme. 2. The enzyme lowers the energy required to complete the reaction. 3. The product is released by the enzyme. Factors that affect rates of enzymes: 1. Temperature—work best at body temp. Cold = slow, Hot = denatured (change shape) 2. Concentration of enzyme--more enzymes to do the work = faster 3. Concentration of substrate—more to work on = the slower it goes 4. Competition with inhibitors—other substances (ex: drugs) block active site = they work slower 5. pH—each enzyme has a “best” pH. Out of that range they denature. In our toothpickase lab….. • What did we do that showed enzyme concentration? • What did we do to show substrate concentration? • What did we do to represent the environment? Denatured Enzyme • Definition: a change in the shape of the enzyme molecule making the enzyme useless or less effective. • The substrate no longer “fits” into its’ Active Site. • Substrate does not fit enzyme does not work Enzyme Animations • http://www.kscience.co.uk/animations/anim _2.htm Can you……..? • Define the key words: enzyme, catalysts, substrate, active site, activation energy, products, denatured and substrate specific • Describe how an enzyme works. • Describe factors that affect enzymes. An Enzyme in Action Can you describe what is happening here? Active Site Which would be the substrate and product for this enzyme? Substrate 1 and products 3/4 P1 Substrate 1 P2 Product Substrate 2 P3 Assignment • Make a study tool – Must have the word or concept – Must have a picture representing the word/concept – Must have a written definition of the word/concept