1. Warm update 10/1 Define these words Chemical reaction Reactant Product Activation energy Catalyst Enzymes Substrate

2. Warm update 10/6 Write the question and answer! What is the purpose of an enzyme? Describe activation energy? What is the role of a substrate?

3. Ms Caldarola Biochemistry: Chemical Reactions and Enzymes

4. Chemical reaction Chemical reaction - a process that changes, or transforms, one set of chemicals into another Mass and energy is conserved during chemical reaction Reactants – elements or compounds that enter into a chemical reaction Product – elements or compound produced by a chemical reaction

5. Chemical reaction What happens to chemical bonds during chemical reaction? Chemical reactions involve changes in the chemical bonds that join atoms in compounds Energy Source? In order to stay alive, organisms need to carry out reactions that require energy Ex: plants trap and store energy from sunlight Ex: animals must consume food to get energy

6. Energy in Reactions Energy is released or absorbed whenever chemical bonds are formed or broken This means chemical reactions involve changes in energy How do energy changes affect whether a chemical reaction will occur? Chemical reactions that release energy often occur on their own Ex: burning of hydrogen gas 2H 2 + O 2  2H 2 O Energy is released in the form of heat Chemical reactions that absorb energy will not occur without a source of energy

7. Activation Energy Activation energy – energy that is needed to get the reaction started Catalyst- a substance that speeds up the rebate of a chemical reaction Catalysts work by lowering the activation energy level

8. Enzymes What role do enzymes play in living things and what affects this function? The role of enzymes is used to speed up chemical reactions that take place in cells Enzymes – are proteins that act as a biological catalysts

9. Enzyme Substrate Complex For a chemical reaction to take place… the reactants must collide with enough energy so that existing bonds will be broken and new bond will form Enzymes provide a site where reactants can be brought together to react Substrates – reactants of enzyme catalyzed reactions

10. Regulation of enzyme activity What can affect the activity of enzymes? Temperature pH Regulatory molecules

11. Enzymes important to the human body Lactase - is an enzymes produced by the small intestines found in the digestive system of Humans. Lactase breaks down lactose, a simple sugar which gives milk its sweetnesslactosesugar Salivary amylase -is a protein enzyme, found in saliva and breaks starch into maltose and dextrin. starchmaltosedextrin amylase is most prominent in pancreatic juice and saliva, each of which has its own isoform of human α -amylasepancreatic juicesaliva It will break large, insoluble starch molecules into soluble starches

12. Enzymes important to the human body Protease -is any enzyme that breaks down proteins into smaller polypeptides or amino acidsenzymeproteins polypeptidesamino acids begins protein catabolism by hydrolysis of the peptide bonds that link amino acids together in the polypeptide chain forming the proteinproteincatabolismhydrolysispeptide bonds amino acidspolypeptide Catalase - common enzyme found in nearly all living organisms exposed to oxygen (such as vegetables, fruit or animals).enzyme It catalyzes the decomposition of hydrogen peroxide in living tissue. It is a very important enzyme in protecting the cell from oxidative damage by reactive oxygen species (ROS).catalyzesoxidative damagereactive oxygen species