Enzymes are proteins that act as catalysts to accelerate chemical reactions in living organisms. They are highly specific and only catalyze particular reactions. Enzymes work by weakening the bonds of reactants, reducing the amount of energy needed for the reaction to occur. The substance an enzyme acts on is called the substrate, which binds to the enzyme's active site to induce a shape change that facilitates the reaction. Environmental conditions like temperature and pH can impact enzyme activity, as can cofactors, coenzymes, and enzyme inhibitors.

1. Enzymes By Muhammad Asif Pu Pak Muhammad Asif Pu

2. What Are Enzymes? Most enzymes are Proteins ( tertiary and quaternary structures) Act as Catalyst to accelerates a reaction Not permanently changed in the process Muhammad Asif Pu

3. Enzymes Are specific for what they will catalyze Are Reusable End in – ase -Sucrase -Lactase -Maltase Muhammad Asif Pu

4. How do enzymes Work? Enzymes work by weakening bonds which lowers activation energy Muhammad Asif Pu

5. Enzymes Muhammad Asif Pu Free Energy Progress of the reaction Reactants Products Free energy of activation Without Enzyme With Enzyme

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7. Enzyme-Substrate Complex The substance (reactant) an enzyme acts on is the substrate Substrate Joins Muhammad Asif Pu Enzyme

8. Active Site A restricted region of an enzyme molecule which binds to the substrate . Substrate Active Site Muhammad Asif Pu Enzyme

9. Induced Fit A change in the shape of an enzyme’s active site Induced by the substrate Muhammad Asif Pu

10. Induced Fit A change in the configuration of an enzyme’s active site (H+ and ionic bonds are involved). Induced by the substrate . Muhammad Asif Pu Enzyme Active Site substrate induced fit

11. What Affects Enzyme Activity? Three factors: 1. Environmental Conditions 2. Cofactors and Coenzymes 3. Enzyme Inhibitors Muhammad Asif Pu

12. 1. Environmental Conditions 1. Extreme Temperature are the most dangerous - high temps may denature (unfold) the enzyme. 2. pH (most like 6 - 8 pH near neutral) 3. Ionic concentration (salt ions) Muhammad Asif Pu

13. 2. Cofactors and Coenzymes Inorganic substances (zinc, iron) and vitamins (respectively) are sometimes need for proper enzymatic activity . Example: Iron must be present in the quaternary structure - hemoglobin in order for it to pick up oxygen. Muhammad Asif Pu

14. Two examples of Enzyme Inhibitors a. Competitive inhibitors : are chemicals that resemble an enzyme’s normal substrate and compete with it for the active site . Substrate Muhammad Asif Pu Enzyme Competitive inhibitor

15. Inhibitors b. Noncompetitive inhibitors : Inhibitors that do not enter the active site , but bind to another part of the enzyme causing the enzyme to change its shape , which in turn alters the active site . Substrate Muhammad Asif Pu Enzyme active site altered Noncompetitive Inhibitor

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