Describe the function of enzymes in the digestion of food. • Describe the chemical composition of carbohydrates, proteins, and lipids. • Describe the chemical tests performed on food and explain the results.

Overview
Biological macromolecules are large, complex organic molecules
that are synthesized and used by living organisms. These
biological macromolecules can be divided into four categories:

carbohydrates, lipids, proteins, and nucleic acids. Food consists
of these molecules. Biological macromolecules cannot pass
through the intestinal wall unless they are converted to smaller
molecules by digestive enzymes. In this investigation, you will
perform standard chemical tests for carbohydrates, proteins, and
lipids. Then you will model enzymatic digestion of protein and
starch under conditions simulating the stomach and intestines.
The effects of temperature and pH on enzymatic activity will also
be tested.

Outcomes
• Describe the function of enzymes in the digestion of food.
• Describe the chemical composition of carbohydrates, proteins,
and lipids.
• Describe the chemical tests performed on food and explain the
results.
• Model the gastric digestion of protein and evaluate the effect of
pH on the process.
• Model the salivary digestion of starch.