1 Enzymes

Brief introductory enzyme video: Goofy video on how enzymes work: 2

3 What Are Enzymes? Proteins (Most enzymes are Proteins (tertiary and quaternary structures) CatalystAct as Catalyst to accelerate a reaction Not permanentlyNot permanently changed in the process

4Enzymes catalyzeAre specific for what they will catalyze ReusableAre Reusable aseEnd in –ase-Sucrase-Lactase-Maltase

5 How do enzymes Work? lowering activation energy which speeds up a reaction Enzymes work by lowering activation energy which speeds up a reaction

6Enzymes Free Energy Progress of the reaction Reactants Products Free energy of activation Without Enzyme With Enzyme

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8 Enzyme-Substrate Complex substance enzyme substrate The substance (reactant) an enzyme acts on is the substrate Enzyme Substrate Joins

9 Active Site restricted region enzyme bindssubstrateA restricted region of an enzyme molecule which binds to the substrate. Enzyme Substrate Active Site

10 Induced Fit shapeA change in the shape of an enzyme’s active site InducedInduced by the substrate

11 Induced Fit changeconfiguration enzyme’s active siteA change in the configuration of an enzyme’s active site (H+ and ionic bonds are involved). Inducedsubstrate.Induced by the substrate. Enzyme Active Site substrate induced fit

12 What Affects Enzyme Activity? Three factors:Three factors: 1.Environmental Conditions 2.Cofactors and Coenzymes 3.Enzyme Inhibitors

13 1. Environmental Conditions 1. Extreme Temperature are the most dangerous 1. Extreme Temperature are the most dangerous - high temps denature (unfold) enzyme. - high temps may denature (unfold) the enzyme. 2.pH (most like pH near neutral) 3.Ionic concentration (salt ions)

14 2. Cofactors and Coenzymes Inorganic substances (zinc, iron) vitamins enzymatic activity Inorganic substances (zinc, iron) and vitamins (respectively) are sometimes needed for proper enzymatic activity. Example:Example: Ironquaternary structure-hemoglobin pick up oxygen. Iron must be present in the quaternary structure - hemoglobin in order for it to pick up oxygen. Other enzymes are s Other enzymes are sometimes needed to activate another enzyme.

Our food is made up of: Carbohydrates: Bread, Pasta, Potato Protein: Meat, Nuts, Lentils Fats: Butter, Milk Our body needs to digest them – turn them into a form that can be absorbed into the blood and used by cells. Enzymes make this possible. Enzyme video/animation: 15

Enzymes that work on carbohydrates: Salivary Amylase + Starch  Maltose (in saliva) (in pasta, bread (a form of sugar that carbohydrate) can be absorbed by the body ) 16

Enzymes that work on Proteins: Protease + Proteins  Amino Acids (in stomach) (eg. In meat, nuts) (the body can absorb them and use them) 17

Enzymes that work on Fats: Lipase + Fats  Fatty Acids + Glycerol (secreted by pancreas) (Butter, Milk ) (can be absorbed into body) 18