AGENDA – 9/11/2015 Take out journal and pick up an exam study guide! Bell-Ringer: RERUN Enzyme Discussion and Notes If time, work on Exam Study Guide! 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 Many proteins are enzymes Enzymes catalyze chemical reactions AA A

Proteins Shape A protein’s shape is determined by the order that amino acids are joined in The shape of a protein determines its function Hemoglobin antibody enzymes polymerase

Four Levels of Structure allow for any shape 2-28 Protein Structure

Degrees of Protein Structure Proteins have four stages or steps to how they are built, and end up in their final shape. Primary Degree of Structure: The order of amino acids in the chain. Secondary Degree of Structure: Spirals and pleats

Degrees of Protein Structure Tertiary Degree of Structure: Big folds Quarternary Degree of Structure: Binding with other folded proteins

Chemical reactions of life Processes of life –building molecules synthesis –breaking down molecules digestion ++

Hydrolysis A water molecule is absorbed to break apart a polymer. This is called Hydrolysis.

Hydrolysis Simplified

Dehydration Synthesis Monomers can be linked together through the process of Dehydration Synthesis Because Water is Formed!

Dehydration Synthesis Simplified

Nothing works without enzymes! How important are enzymes? –all chemical reactions in living organisms require enzymes to work building molecules –synthesis enzymes breaking down molecules –digestive enzymes –enzymes speed up reactions “catalysts” ++ enzyme We can ’ t live without enzymes!

Enzymes as catalysts Catalyst - Speeds up chemical reactions in living organisms by decreasing the energy needed to start the reaction (activation energy) Energy Time Without a catalyst With a catalyst

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 enzyme substrateproduct active site

Basic Enzyme Diagram Active site The substrates have reacted and changed into the product Enzyme is unchanged

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 Active site of the enzyme Two substrates Enzyme

Lock and Key Model The active site is like a lock The substrates fit like a key in a lock Enzyme

Lock and Key Model The activation energy for these substrates to bind together has been lowered by the enzyme. Enzyme Chemical reaction!!!

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? PolymerMonomer 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

What is an acid? An acid is a solution that has an excess of H+ ions. It comes from the Latin word acidus that means "sharp" or "sour". The more H + ions, the more acidic the solution.

What is a base? A base is a solution that has an excess of OH- ions. Another word for base is alkali. Bases are substances that can accept hydrogen ions

pH Scale pH is a measure of how acidic or basic a solution is. The pH scale ranges from 0 to 14. Acidic solutions have pH values below 7 A solution with a pH of 0 is very acidic. A solution with a pH of 7 is neutral. Pure water has a pH of 7. Basic solutions have pH values above 7.

7 pH reaction rate stomach pepsin intestines trypsin What’s happening here?!

37° Temperature temperature reaction rate What’s happening here?! human enzymes

Graphing enzyme activity Increasing activity Denaturation: enzyme is ruined Optimum Enzyme activity Temperature (C)

Increasing activity Denaturation: enzyme is ruined Optimum Enzyme activity Temperature (C) The optimal temperature for this enzyme is __________

Order of amino acids Wrong order = wrong shape = can’t do its job! DNA chain of amino acids folded protein right shape! wrong shape!

For enzymes… What matters? SHAPE!