Enzymes as catalysts

Experiment # 10: How enzymes work

Materials Needed:
* Two jars with lids
* diluted hydrochloric acid
* ground beef (raw)
* iodine
* crackers
* cornstarch
* dextrostik strips (to test for sugar)

Procedure:
1) In one jar, place diluted hydrochloric acid (muriatic acid) and a piece of ground beef.
2) In the second jar, put a piece of ground beef. Leave for 24 hours.
3) After 24-hours, compare the beef on both jars.
4) What is your explanation?

5) Chew a cracker for 30 seconds without swallowing.
6) Describe the change in flavor and explain the result.

7) Collect several teaspoons of saliva in a glass (saliva contains enzyme amylase).
8) Mix a paste of 1T. cornstarch and 1 c. of water.
9) Heat to boiling and cook for 10 min. Stir to prevent burning.
10) Put  1T. of the thick paste into each of  2 jars.
11) Add 1T. of saliva to one jar and 1T. of water to the other. Place in warm place for 1 hour.
12) Examine visually.
       * Describe any difference in appearance.
13) Perform the carbohydrate test on each for sugar.
      * Describe the result.
14) Perform  the carbohydrate test for starch on each.
      * Describe the result.

Findings

Photo above:
Clockwise: Jars of meat after 24 hrs; jars of meat before putting muriatic acid on one jar; water jar tested for starch; water jar tested for sugar; saliva jar tested for starch; saliva jar tested for sugar.

Findings:
* Beef with the acid rapidly decomposed.
* Jar with saliva and corstarch appears clearer than the jar with water. It has sugar but does not show starch.
*Jar with water and cornstarch has no sugar but has starch.
* That enzyme amylase in saliva turns starch in food to sugar while being chewed. That is why the crackers tasted sweeter.
* Digestion breaks down proteins into its component amino acids.