CHS students taking Living Environment with Ms. Kneller have been studying enzymes this week. Students learned that enzymes only work with specific substrates within the body; similar to a lock and key in which the key only works with a certain lock, enzymes only will work with certain substances (substrates). Each enzyme is used again and again in the body, which makes enzymes very efficient. However, if an enzyme is exposed to pH or temperature extremes, it will change shape and no longer work. This is called denaturation.
During a lab, the students observed how heat and pH affect enzyme action by experimenting with catalase. Catalase is an enzyme found in animal tissue that removes hydrogen peroxide from the body (hydrogen peroxide would be deadly if our bodies did not have catalase to break it down). The students used chicken liver to simulate live tissue and witnessed the reaction that hydrogen peroxide had with raw chicken liver, chicken liver in acid, and cooked chicken liver. The students observed little to no reaction in both the cooked liver and the liver in acid because the catalase enzyme was denatured! However, the raw liver mimicked healthy animal tissue and displayed a bubbly reaction to the hydrogen peroxide due to the presence of catalase – the students loved it!