The movement of water and solutes into/out of the cells of the body is crucial to homeostasis and health. This lab activity has been broken up into four activities that can be used to relay the importance of homeostasis in the body.

Lab 03a – Cell Tonicity

• Students take the roll of a patient educator. A dehydrated patient is refusing the 0.9% saline IV solution, and it is the student’s job to explain with a visual example why it must be 0.9% saline. The students will be required to create an experiment with limited supplies. This activity focuses on osmosis as well as experimental design.

Lab 03b – Red Blood Cell Tonicity

• Students will use animal blood purchased from a butcher source to observe the effects of tonicity on red blood cells. Red blood cells will be exposed to hypertonic, hypotonic, and isotonic saline solutions. Following exposure, the red blood cell solutions will be observed with a microscope.

Lab 03c – Hemolysis

• Using animal blood, students will observe the effects of four different unknown solutes on the tonicity, and possible lysis, of red blood cells. Using chemical information for the possible solutes and time until hemolysis, students will make inferences on what the unknown solutes may be.

Activity 03d – pH of the Body

• Students will test their own salivary pH over a 24-hour period. Following the 24-hour period, data will be collected for the class and a histogram created for data analysis. The importance of maintaining a healthy body pH for normal bodily functions will be discussed.

Items included in this lab are listed below.

Rulers, Weighing boats, Plastic pipettes, pH strip color charts.