1. Enzymes By – Mehak chandel Post Basic 1 st year

2. What Are Enzymes? Proteins (Most enzymes are Proteins (tertiary and quaternary structures) CatalystAct as Catalyst to accelerates a reaction Not permanentlyNot permanently changed in the process Mehak Chandel (Post Basic ) 1st Year 6/2/2016

3. Enzymes catalyzeAre specific for what they will catalyze ReusableAre Reusable aseEnd in –ase-Sucrase-Lactase-Maltase Mehak Chandel (Post Basic ) 1st Year 6/2/2016

4. How do enzymes Work? weakening bonds which lowers activation energy Enzymes work by weakening bonds which lowers activation energy Mehak Chandel (Post Basic ) 1st Year 6/2/2016

5. Enzymes Free Energy Progress of the reaction Reactants Products Free energy of activation Without Enzyme With Enzyme Mehak Chandel (Post Basic ) 1st Year6/2/2016

6. Mehak Chandel (Post Basic ) 1st Year 6/2/2016

7. The Lock and Key Hypothesis substance enzyme substrate The substance (reactant) an enzyme acts on is the substrate Enzyme Substrate Joins Mehak Chandel (Post Basic ) 1st Year 6/2/2016

8. Active Site restricted region enzyme bindssubstrateA restricted region of an enzyme molecule which binds to the substrate. Enzyme Substrate Active Site Mehak Chandel (Post Basic ) 1st Year 6/2/2016

9. Induced Fit shapeA change in the shape of an enzyme’s active site InducedInduced by the substrate Mehak Chandel (Post Basic ) 1st Year6/2/2016

10. 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 Mehak Chandel (Post Basic ) 1st Year 6/2/2016

11. What Affects Enzyme Activity? Three factors:Three factors: 1.Environmental Conditions 2.Cofactors and Coenzymes 3.Enzyme Inhibitors Mehak Chandel (Post Basic ) 1st Year 6/2/2016

12. 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 6 - 8 pH near neutral) 3.Ionic concentration (salt ions) Mehak Chandel (Post Basic ) 1st Year 6/2/2016

13. 2. Cofactors and Coenzymes Inorganic substances (zinc, iron) vitamins enzymatic activityInorganic substances (zinc, iron) and vitamins (respectively) are sometimes need 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. Mehak Chandel (Post Basic ) 1st Year6/2/2016

14. 3. The effect of enzyme inhibition Mehak Chandel (Post Basic ) 1st Year 6/2/2016

15. The effect of temperature For most enzymes the optimum temperature is about 30°C Many are a lot lower, cold water fish will die at 30°C because their enzymes denature A few bacteria have enzymes that can withstand very high temperatures up to 100°C Most enzymes however are fully denatured at 70°C Mehak Chandel (Post Basic ) 1st Year6/2/2016

16. The effect of pH Extreme pH levels will produce denaturation The structure of the enzyme is changed The active site is distorted and the substrate molecules will no longer fit in it At pH values slightly different from the enzyme’s optimum value, small changes in the charges of the enzyme and it’s substrate molecules will occur This change in ionisation will affect the binding of the substrate with the active site. Mehak Chandel (Post Basic ) 1st Year6/2/2016

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18. 6/2/2016Mehak Chandel (Post Basic ) 1st Year