Skip to Content

Apple and Linguine

All About the Digestive System


Jennifer Jackson
Department of Biology
Coastal Carolina University
Karen M. Aguirre
Department of Biology
Coastal Carolina University


This flipped case study is suited for general education undergraduate level biology. Students prepare ahead of time for class by viewing a video created by the authors that reviews the basics of nutrition and digestion; in class, students then engage in three activities to further explore aspects of the video's content using specific and concrete examples of diverse foods. During the first part of the case study, students learn information about balanced diets, nutrition and the digestive system. Students apply their knowledge on how food passes through the digestive tract, and how absorption and breakdown of nutrients occur by explaining and presenting the process based on assigned food items. Students are then asked to further apply their knowledge when presented with two scenarios ("mini-cases"), one involving gastric bypass surgery and the other the effects of cholera.


  • Identify individual food items in terms of nutrient value, i.e., is the food a carbohydrate, fat, or protein?
  • Understand the relative proportions one should eat to achieve a balanced diet.
  • Understand the sequential functions of the organs of the digestive system.
  • Demonstrate how individual foods pass through the digestive system, mobilizing nutrients for use (and also creating waste), and what happens at each step.
  • Discuss how disruption of the physical activities of the gastrointestinal tract may affect human health.


digestion; digestive system; gastrointestinal tract; GI tract; cells; enzymes; cellular absorption

Topical Areas


Educational Level

High school, Undergraduate lower division



Type / Methods

Analysis (Issues), Flipped, Mini-Case



Subject Headings

Biology (General)  |   Cell Biology  |   Science (General)  |  

Date Posted


Teaching Notes

Case teaching notes are password-protected and access to them is limited to paid subscribed instructors. To become a paid subscriber, begin the process by registering.

Teaching notes are intended to help teachers select and adopt a case. They typically include a summary of the case, teaching objectives, information about the intended audience, details about how the case may be taught, and a list of references and resources.

Supplemental Materials

The optional supplemental material listed below is appropriate for use with this case study.

  Down the Gullet: A Guided Tour of Your Guts “Science

Answer Key

Answer keys for the cases in our collection are password-protected and access to them is limited to paid subscribed instructors. To become a paid subscriber, begin the process by registering.


The following video(s) are recommended for use in association with this case study.

  • Apple and Linguine: All About the Digestive System
    This lighthearted video takes a look at the individual organs of the digestive system, how food is digested into usable nutrients, and how those nutrients are mobilized to different parts of the body. Running time: 14:05 min. Created by Jennifer Jackson and Karen Aguirre for the National Center for Case Study Teaching in Science, 2017.
  • Roux-en-Y Gastric Bypass
    This brief animation from the Mayo Clinic describes the Roux-en-Y gastric bypass procedure. Running time: 0:48 min. Produced by the Mayo Clinic, 2012.
  • The Claymation of Cholera
    This claymation video introduces a camper who drinks water contaminated with Vibrio cholera, and describes the mechanism of action of cholera toxin. The toxin disrupts the function of the chloride transport system in the small intestine, resulting in abnormal water partition in the small bowel, with life-threatening excretion of fluid in the form of rice-water-stool. Running time: 2:04 min. Produced by the “Clay mators,” 2012.