1. Enzymes

2. What are Enzymes? proteins Most enzymes are proteins catalyst Act as catalyst to accelerate a reaction Not permanently Not permanently changed in the process catalyze Are specific for what they will catalyze Reusable Are Reusable Work with substrate molecules to either build or break them down. Work with substrate molecules to either build or break them down. ase End in –ase -Sucrase-breaks down disaccharide sucrose to simple sugars -Lactase-breaks down disaccharide lactose to simple sugars

3. Enzymes and Substrates form temporary complexes

4. How do Enzymes work to build a protein needed by the body? (anabolism)

5. How does the enzyme sucrase break down sucrose? (catabolism)

6. Activation Energy This is the energy needed for a reaction to proceed. Enzymes work by weakening bonds which lowers activation energy Helps to speed up chemical reactions in the Body.

7. Enzymes Lower Activation Energy 7 Free Energy Progress of the reaction Reactants Products Free energy of activation Without Enzyme With Enzyme

8. What Affects Enzyme Activity? 1.) Environmental Conditions – Extreme temperatures are the most dangerous-may denature (unfold) the enzyme. – pH -most enzymes prefer pH from 6 - 8 near neutral – Ionic concentration (salt ions) 8

9. What Affects Enzyme Activity? (cont.) 2.) Cofactors and Coenzymes – Inorganic substances (zinc, iron) and vitamins (respectively) are sometimes need for proper enzymatic activity. – Used in making ATP in cellular respiration Ex: Iron must be present in the quaternary structure of hemoglobin to pick up oxygen in the blood. 3.) Inhibitors – Many drugs block enzyme activity

10. Examples of common enzymes in the body Metabolic enzymes – Used to catalyze reactions that produce energy. Digestive enzymes – Amylase: This enzyme helps in breaking down carbohydrates. It is found in saliva, pancreas and intestinal juices. – Proteases: It helps in digestion of proteins. It is present in the stomach, pancreatic and intestinal juices. – Lipases: Lipases assist in digestion of fats. It is seen in the stomach, pancreatic juice and food fats. Food enzymes