AGENDA – 9/11/2015 • Take out journal and pick up an exam study guide! • Bell-Ringer: RERUN • Enzyme Discussion and Notes • Exam Study Guide Questions #1,2,4,5,7,8 • Homework: – UNIT 1.1 Test: Wednesday, 9/16 – EXAM STUDY GUIDE! Bell-Ringer: 9/11/15 RERUN – Toothpickase Lab • • • • • Recall: Summarize what you did yesterday. Explain: Explain the purpose. Results: Describe the results and what they mean. Uncertainties: Describe what you are still unsure about. New: One new thing you learned. Enzymes: “Helper” Protein molecules Review Macromolecules • Proteins Amino acids • Carbohydrates Sugars – (monosaccharides, polysaccharides, glucose) • Lipids Fatty acids and a glycerol molecule • Nucleic Acids Nucleotides Proteins • Chains of amino acids AA • Many proteins are enzymes • Enzymes catalyze chemical reactions AA AA AA A A AA Chemical reactions of life • Processes of life – building molecules • synthesis + – breaking down molecules • digestion + Nothing works without enzymes! • How important are enzymes? – all chemical reactions in living organisms require enzymes to work enzyme • building molecules – synthesis enzymes • breaking down molecules We can’t live without enzymes! + enzyme – digestive enzymes – enzymes speed up reactions • “catalysts” + Enzymes as catalysts • Catalyst - Speeds up chemical reactions in living organisms by decreasing the energy needed to start the Energy reaction (activation energy) Without a catalyst With a catalyst Time Enzymes aren’t used up • Enzymes are not changed by the reaction – used only temporarily – re-used again for the same reaction with other molecules – very little enzyme needed to help in many reactions substrate active site product enzyme Basic Enzyme Diagram The substrates have reacted and changed into the product Enzyme is unchanged Active site It’s shape that matters! • Lock & Key model – shape of protein allows enzyme & substrate to fit – specific enzyme for each specific reaction Lock and Key Model Two substrates Enzyme Active site of the enzyme Lock and Key Model The substrates fit like a key in a lock Enzyme The active site is like a lock Lock and Key Model The activation energy for these substrates to bind together has been lowered by the enzyme. Chemical reaction!!! Enzyme In Biology when a word ends in –ase it is more than likely it’s an enzyme. Guess what polymers are broken down by these enzymes and what monomers are created? Polymer Monomer •Protease ________ ___________ •Sucrase ________ ___________ •Lipase ________ ___________ Enzyme vocabulary • Enzyme – helper protein molecule • Substrate – molecule that binds to the active site and what enzymes work on • Products – what the enzyme helps produce from the reaction • Active site – part of enzyme that substrate molecule fits into Enzymes are very complex structures whose shapes and functions can be affected by many factors What factors affect enzyme function? pH Temperature pH • Effect on rates of enzyme activity – changes in pH changes protein shape~ Denatures – most human enzymes = pH 6-8 • depends on where in body • pepsin (stomach) = pH 3 • trypsin (small intestines) = pH 8 pH intestines trypsin What’s happening here?! reaction rate stomach pepsin 0 1 2 3 4 5 6 pH 7 8 9 10 11 12 13 14 Temperature reaction rate human enzymes 37° temperature What’s happening here?! Graphing enzyme activity Optimum Enzyme activity Denaturation: enzyme is ruined Increasing activity 20 30 40 50 Temperature (C) 60 The optimal temperature for this enzyme is __________ Optimum Enzyme activity Denaturation: enzyme is ruined Increasing activity 20 30 40 50 Temperature (C) 60 Order of amino acids • Wrong order = wrong shape = can’t do its job! chain of amino acids DNA folded protein right shape! folded protein chain of amino acids DNA wrong shape! For enzymes… What matters? SHAPE!