Salt: The Essence of Life
Multidisciplinary Curriculum for Students
Unit 7: Nutrition
Salt for Human Nutrition
1 Class Period
Overview
This module focuses on the need for salt in our diet. Students will discover that sodium chloride along with calcium, magnesium, and potassium are essential ions.
Background
Salt is known as sodium chloride and has the chemical formula NaCl. By weight, salt is 40% sodium and 60% chloride. Most foods and tap water contain sodium and chloride. Sodium is an essential nutrient, a mineral that the body cannot manufacture itself.
Because of sodium's importance to your body, the excretory and nervous systems guard against under-consumption of salt, which is a threat to your body's nerves and muscles. Other ions such as calcium, magnesium, and potassium are also very important. Concentrations of these ions are held in narrow ranges by the kidney. Calcium is found in all dairy products, beans, nuts, and seeds, and is used for building bones and teeth, blood clotting, and muscle contraction. Magnesium is found in beans, nuts, dark green vegetables, and lean meats, and is used to produce protein, build bones, and regulate body temperature. Potassium is found in most fruits and vegetables, and assists in muscle contraction, fluid regulation, and nerve impulses.
Getting Ready
Time: 1 class period
Materials
Per Student Group: 4 feet of string, 2 dowels that are 1/2" in width and 12" in length, or a coat hanger cut into 4 pieces, poster board, tape
Instructions
Distribute materials to each student group
Activity
1. The purpose of the activity is to create an Ion Nutrition Mobile that illustrates the balance of the 4 ions: Na+, Mg++, Ca++, and K+.
2. Tape the dowels together in the middle forming an X, and tie a string to the junction point so the mobile can be suspended from the ceiling.
3. Each section of the dowel will represent one of the four ionic groups.
4. The label for the ion should be made from poster board and held by string at the end of the dowel.
5. Based on information gathered in texts, encyclopedias, and articles students will identify different types of foods which have high concentrations of the specific ions.
6. From poster board, students will create pictures of food which should be hung on the dowel associated with its ion.
Assessment
The craftsmanship and the nutritional understanding, as revealed in the mobiles, are the basis for assessment.
Conclusion
Hang the mobiles around the classroom to visualize the need for an ionically balanced diet, and which reflects the body's need for these ions. Ask students what could cause an imbalance of the body's ions (as in the mobile).