3. Testing for Life's Molecules

Summary
All known life is made out of a small group of chemical compounds called organic molecules. Common organic molecules include proteins, glucose, starch, lipids, and nucleic acids. This lesson plan asks students to conduct tests for proteins, glucose, and starch. At the beginning of the activity, they choose 3 items to test: one known to be “never alive”, one known to be “once was alive”, and one mystery item. In addition, each station includes a positive control. By the end of the experiment, students should be familiar with some of the major organic molecules and should recognize that living things, and substances derived from them, are made of organic molecules. In addition, this is a chance to bring in topic surrounding nutrition, health, and digestion. Since our bodies are made up of organic molecules, we need each of these molecules as nutrients in our food.

Objectives

Can define and give examples of organic molecules.
Can recognize that living things are mode of organic molecules.
Can test for the presence of protein, glucose and starch.
Can interpret the results of an experiment.

Vocabulary
Organic molecule
Protein
Biuret solution
Carbohydrates
Glucose
Simple sugar
Benedict’s solution
Starch
Iodine
Lipids

AttachmentSize
3testing_life.doc63 KB
life_test_directions.doc34 KB
life_test_handout.doc40 KB