Chemical Reactions Review Chemical Reactions Process that changes

Chemical Reactions Review • Chemical Reactions: – Process that changes one set of chemicals into another – Bonds are broken and reforming – Reactant(s) Product(s) – Energy is released or gained – Require activation energy

Chemical Reactions Review • Activation Energy: the minimum energy required to start a chemical reaction. • http: //www. youtube. com/watch? v=Vb. Ia. K 6 PLr. RM • Energy Diagram: Reaction occurs @ peak Reactants: Products:

Energy in Reactions Endothermic Reaction Exothermic Reaction

Catalysts • Substance that speeds up a chemical reaction by lowering energy barriers. • Biological Catalysts are called: ENZYMES

Enzymes • Are catalysts. • They speed up one type of chemical reactions that take place in cells. –They are substrate specific

Enzymes are Proteins • Review: – Elements: C, H, O, N – Monomer: Amino Acids – Polymer: Protein or Polypeptide • Proteins have 4 levels of organization

Four levels of organization Primary Structure: order of the amino acids in the protein chain Secondary Structure: the protein chain twisted or folded Tertiary Structure: the chain folded Quaternary Structure: clustering of multiple protein chains into the final three dimensional

Enzymes are Specific • Enzymes catalyze only one chemical reaction • Enzymes are commonly named by adding a suffix "-ase" to the root name of the substrate molecule it acts on or job it does. • What are the following enzymes acting upon? – Lipase – Lactase – Sucrase – RNAase

Enzyme-substrate Complex: Induced Fit Active Site

Coenzymes and Cofactors

Ideal Working Conditions • Enzymes have an optimal temperature and p. H range. • What temperature do enzymes work best in humans?

Enzyme Inhibitors • Inhibitors are molecules that prevent enzymes from working in their normal fashion • There are two types: – Nonspecific: Denatures enzymes • • Temperature p. H Alcohol Heavy Metals – Specific: Blocks or alters active sites. • Competitive • Noncompetitive

Competitive v. Noncompetitive