Unit D

Module 6 Introduction


The digestive system is important to maintain homeostasis in humans through the exchange of energy and matter with the environment. The human body depends on large organic molecules for energy. Vitamins, minerals, and other inorganic molecules are also important to cellular functions. The structures of the digestive system work together to maintain metabolic equilibrium in the body.

Diseases may interfere with body functions in the digestive system and cause undernourishment or other digestive symptoms. What happens to your body if your digestive system fails to work properly? Technology is available to treat and prevent disorders related to the digestive system.

Pie-eating contest, Seattle, Washington, 2003. Item 144037, Fleets and Facilities Department Imagebank Collection (Record Series 0207-01), Seattle Municipal Archives.
Competitive eating is a potentially dangerous activity that challenges the limits of the human digestive system. Some findings suggest that competitive eating can interfere with the normal muscle contractions in the digestive system as well as put competitors at risk for obesity, elevated cholesterol and elevated blood pressure1. However, many competitive eaters are not overweight and exercise regularly.

1. Burbach, Cherie. "Health Risks of Speed Eating."Blisstree.com". July 3, 2009.

Big Ideas

This module will investigate the human digestive system and its role in the exchange of energy and matter with the environment.

By the end of this module, you should be able to
  • explain how the human digestive system exchanges energy and matter with the environment.

Key Concepts

Concepts that you should be able to explain by the end of this module are
  • the basic chemical structure of starch, sugars, fat and protein
  • the structures in the digestive system and their function in digestion
  • enzyme actions and factors affecting enzyme function
  • chemical and physical processing of food in the digestive system, including the names and functions of enzymes


Skills that you should be able to do by the end of this unit are
  • write a procedure to detect the presence of macromolecules and the digestion of macromolecules
  • interpret the results of the above experiments
  • analyze data from an experiment examining the effect of temperature and pH on enzyme function
  • identify the major structures of the digestive system in a diagram


There are three graded assessments in Module 6.

  1. Unit D: Section 1 Assignment
  2. Unit D: Section 2 Assignment
  3. Unit D Summative Part 1

As you work through this unit and its module, you will find Self-Check questions,  labs, and critical thought questions. There will be lesson goals indicated at the beginning of each lesson and then clearly identified throughout the lesson.