2. Enzymes Enzymes are special proteinsthat help control chemical reactionsby acting as catalysts. Catalysts can speed up some reactions by more than a billion fold.
3. 3. How they work Enzymes work by a physical fit (Lock and Key) between the enzyme and the substrate. When connected the enzyme lowers the activation energy needed for the chemical reaction.
7. 5. Inhibition Certain substances can inhibit enzyme function. Competitive inhibitors: Get in the way…they “fit” into the active site.
8. 5. Inhibition c. Noncompetitive (Allosteric) inhibitors: Change the shape of the enzyme so the substrate(s) no longer fit. Substrate Enzyme NC Inhibitor Enzyme
11. 6. Environmental Factors Environmental Factors can affect enzymes activity. Temperature pH Salt More… Really cold…slows down enzymes Too hot, too salty, pH…DENATURE (unfold, change shape) Denatured protein
12. Questions??? Quick review: What type of macromolecule are enzymes? What is the “lock-and-key” model mean? How do enzymes speed up chemical reactions? What are the two types of competitors? How do they work? What factors can affect enzyme activity?
