Enzymes From Page 57 (not all of this is in your book!)

Standards ● CLE – Describe how enzymes regulate chemical reactions in the body. ● Class Objectives: ● Describe how the enzyme and substrate interact to catalyze chemical reactions. ● Describe conditions that affect enzyme function.

Enzymes ● Definition: ● Facts: ● Proteins that act as biological catalysts, lowering activation energy and increasing the rate of chemical reactions. Enzymes are specific to only 1 or 2 chemical reactions. The enzyme’s name is usually from the chemicals in the reaction it catalyzes.

Examples of Enzymes ● DNA polymerase ● Carbonic anhydrase Connects the subunits to make DNA. Helps turn CO 2 into carbonic acid in the blood.

Enzyme-Substrate Complex (Lock & Key Model) ● Substrate: ● Active Site: The reactant(s) of the chemical reaction. Part of the enzyme into which the substrate fits.

Synthesis and Decomposition ● Enzymes can participate in two types of reactions: ● Synthesis: ● Decomposition: Decomposition A reaction in which two or more substrates are combined to form one product. A reaction in which one substrate is separated to form two or more products.

Lab 2 – Effects of Temperature ● Fresh pineapple juice was heated to boiling (100 degrees C) ● Room Temperature Juice – enzymes broke down jell-O. ● Boiled Juice – Did not break down jell-O.

Pineapple Lab Summary ● Lab 1 – Different Pineapple Juices ● Fresh Juice – Contains enzymes that break down the protein in the Jell-O. ● Canned Juice – When can was heated during processing it denatured the enzymes. ● Frozen Juice – When juice was frozen many of enzymes were denatured so only a small amount of jell-O was broken down.

Lab 3 – Effects of pH ● Fresh Pineapple Juice with: ● Water (neutral) – Enzymes broke down jell-O ● Vinegar (weak acid) – Enzymes broke down more jell-O than water. ● Bleach (strong base) – No jell-O was broken down.

Enzyme Regulation ● Enzyme activity can be regulated by: ● Temperature: ● pH: Each enzyme has an optimum temperature. Too high or too low can denature proteins the enzyme is made of. Each enzyme has an optimum pH. Too acidic or too basic can denature proteins the enzyme is made of.

Protein denaturation ● Normal, functional Denatured proteinprotein

Did We? ● CLE – Describe how enzymes regulate chemical reactions in the body. ● Class Objectives: ● Describe how the enzyme and substrate interact to catalyze chemical reactions. ● Describe conditions that affect enzyme function.

Table Talk ● Answer the following questions with your table. We’ll discuss them in a minute. ● Why are enzymes necessary for survival?