Enzymes

1. Enzymes By Mr. Scott

2. What are Enzymes? Sucrase

3. Enzymes • Are special kinds of proteins • Increase the speed of biochemical reactions • Increase chances of correct molecules/atoms colliding • Decrease the activation energy of reactions • DO NOT get used up in the reaction • Have “Active Sites” that bind to specific Substrates • Some RNA molecules called Ribosymes also act as enzymes in reactions

4. Examples of Enzyme Assisted Reactions Lactose is broken down by the enzyme Lactase into Glucose and Galactose (Lactose intolerance is due to low levels of Lactase) Amylose (starch) is broken down by the enzyme Amylase into Maltose

5. Enzyme Names • What did you notice about the names of the sugars and enzymes that break them down on the last slide? • Sugar = ose Enzyme = ase

6. Effect of Enzymes

7. Environmental Effects on Enzymes • Enzymes have an “optimal range” in which they function best. • Enzymes being proteins can become “Denatured” and stop functioning • Denatured means to lose its structure which for proteins/enzymes defines their function. • Example of Denatured proteins -- fried eggs • Causes: Heat, Acids/Bases, Alcohol, Heavy Metal Salts

8. Fried Eggs When heated the protein in the “egg white” actually turns from clear to white in color due to the loss of the proteins’ structure. This same reaction occurs when acid (pH below 7) is dropped onto the eggs. WHY?? So what does this mean for enzymes? They are proteins so heat and pH can denature them which is why it is important for living organisms to maintain homeostasis which will allow enzymes to continue to work correctly.

9. Enzymes of Digestion What does this graph tell you about the typical pH levels in the Stomach (where pepsin is) and the Small Intestines (where trypsin is)?

10. Short Constructed Response time Using what we’ve just learned about enzymes, write a 5-7 sentence response to the following prompt. Why do you get a fever when you are sick? (Hint – what might it do to the invading cells?)