ENZYMES Enzymes are organic compounds. They are made up of proteins. They are called organic catalysts Catalysts speed up a reaction but are not used up in the reaction.

Properties of Enzymes speed up the rate of the reaction lower the amount of energy required for a chemical reaction to happen remain unchanged at the end of the reaction

Enzymes either help break things down or put them together. They often end in “ase” Lactase breaks down lactose. Sucrase breaks down sucrose. nd_small.htm

What enzyme is a person who is lactose intolerant missing? Lactase! That is why their stomach hurts.

How do enzymes work? 1.Substrate: the substance that is being broken down. 2.Active Site: The place on the enzyme that connects to the substrate. 3.The active site of the enzyme connects to the substrate and breaks it into the products.

Here is an example of an enzyme breaking down food.

Enzymes in your intestines break down your food. What does protease break the above proteins down into? Amino Acids

Lock and Key Enzymes are specific This means that only 1 substance, or substrate, will fit into each enzyme.(Just like your house key only works at your house.)

Lock and Key The key to your house can open your door many times. An enzyme can also be used over and over again. The key has a specific place on the door.

Several factors can affect the speed of an enzyme Coenzymes: Vitamins or minerals that speed up the rate of enzymes Inhibitors: Things that block an enzyme and slow it down Examples: drugs Denaturation – Factors that change the shape of an enzyme – Examples: Temperature and PH

If you heat the protein above its optimal temperature bonds break. meaning the protein loses it folded up structure This is called denaturing the protein. The active site changes shape so the substrate no longer fits. Effect of heat on enzyme activity

Rate of Reaction Temperature o C - denatures o C Increase in Activity <5 o C - inactive Temperature (degrees C)

If you melt your key, it won’t open your door! /smallpox.htm This is why you feel tired when you are sick.

Rate of Reaction pH pH scale For this enzyme, there are two optimal pH ranges for the enzyme to work. It does not work in other pHs because the active site changes

Do humans need enzymes? YES Uses: Digestion To get our body energy Economic uses: Detergents Many fatal genetic disorders are due to the absence of just ONE enzyme.