1. Chemical Reactions and Enzymes Chapter 2, section 4

2. Enzymes Read Digestion: Enzymes and complete the chart below. When you are done, answer the Enzyme review questions below the chart MacromoleculeEnzyme responsible for break down of macro Where is this enzyme found & produced? Examples of problems that can occur when enz. Is deficient.

3. Digestive Enzymes MacromoleculeEnzyme responsible for break down of macro Where is this enzyme found & produced? Examples of problems that can occur when enz. Is deficient. ProteinProtease (Pepsin and Trypsin) Pepsin: Stomach Trypsin: Pancreas Arthritis, Bone Spurs CarbohydratesAmylaseFound in saliva Produced: Pancreas Asthma, gastritis LipidsLipaseProduced: Pancreas *Bile is pro. By the liver to help lipase work faster High cholesterol, obesity

4. Chemical Reactions Everything in life is based on chemical rxns! Metabolism: all chemical rxns that take place in an organism Chemical rxn: a process that changes, or transforms, one set of chemicals into another

5. Chemical Reactions The elements or compounds that enter into a chemical reaction are the REACTANTS The elements or compounds produced by a chemical reaction are PRODUCTS Energy is released or absorbed whenever chemical bonds form or are broken

6. Energy in Rxns: Exergonic Rxns Exergonic Rxn: chemical rxns that RELEASE energy, often occur spontaneously Ex: H 2 gas burning, or reacting, with O 2 to produce water vapor. Energy is released in the form of heat

7. Endergonic Reactions Endergonic Rxn: chemical rxns that ABSORB energy. Will not occur without a source of energy Energy in Reactions

8. Activation Energy Energy that is needed to get a reaction started Energy is recovered as the reaction proceeds

9. Catalyst Catalyst: a substance that speeds up the rate of a chemical rxn Work by lowering a rxn’s activation energy

10. Enzymes Enzymes are proteins that act as biological catalysts Speed up chemical rxns in cells Reaction pathway without enzyme Activation energy without enzyme Reaction pathway with enzyme Activation energy with enzyme Products

11. Enzyme Substrate Complex Enzymes provide a site where reactants can be brought together to react The reactants (what goes in) of an enzyme-catalyzed rxn are known as substrates How do enzymes work?

12. Example of Enzyme Activities The dehydration reactions of macromolecules! The subunits of our macromolecules are put together to form larger molecules and remove water by the action of an enzyme

13. (Glucose) Substrates- reactants in enzyme catalyzed reaction Substrates bind to enzyme Substrates are converted into products Enzyme- not changed or used up in reaction (hexokinase) Products are released Section 2-4 Active site- place on Enzyme where reaction takes place Dehydration/Condensation Reactions Animated

14. Tomorrow’s Lab… Going to be working with the enzyme Amylase (notice –ase ending) Amylase is responsible for breaking down polysaccharides into monosaccharides (sugars) Think back to last week when we were testing for polysaccharides…what did we add to our suspected polysaccharide sample to induce (hopefully) a color change? Iodine What should happen if you add amylase to a polysaccharide (with iodine already added)?

15. Read Metabolism In your NB copy and answer these questions: 1.What is an anabolic reaction? 2.What is a catabolic reaction? 3.Why are enzymes important in the digestive process? 4.What is the First Law of Thermodynamics? 5.What is the Second Law of Thermodynamics? 6.What is the major link between the energy- yielding reactions of catabolism, and the energy requiring reactions of anabolism?