Enzymes 1 What Are Enzymes Enzymes are Proteins

Enzymes 1

What Are Enzymes? • Enzymes are Proteins • Act as Catalyst to speed up chemical reactions 2

Enzymes • Are specific for what they catalyze • Are Reusable • End in –ase -Sucrase -Lactase -Maltase 3

How do enzymes Work? Enzymes weaken chemical bonds which lowers activation energy (the energy needed to start a reaction) 4

Enzymes Without Enzyme With Enzyme Free Energy Free energy of activation Reactants Products Progress of the reaction 5

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Enzyme-Substrate Complex The substance an enzyme acts on is the substrate Substrate Joins Enzyme 7

Active Site • A restricted region on an enzyme molecule that binds to the substrate Active Site Substrate Enzyme 8

What Affects Enzyme Activity? • Two factors: 1. Environmental Conditions 2. Enzyme Inhibitors 9

1. Environmental Conditions 1. Extreme Temperatures are the most dangerous - high temps denature (unfold) the enzyme. (globular chain) 2. p. H (most like 6 -8 p. H near neutral) 10

2. Two examples of Enzyme Inhibitors Competitive inhibitors: attaches to the active site and blocks substrate a. Substrate Competitive inhibitor Enzyme 11

Inhibitors b. Noncompetitive inhibitors: binds to another part of the enzyme changes the active site. Substrate active site altered Enzyme Noncompetitive Inhibitor 12

http: //www. youtube. com/watch? v=TLr 7_2 wn. IXU 13