Linking Two Worlds: Using Animals to Learn How the Human Body Works Purpose Introduce students to concepts of physiology as it relates to incorporation of dietary items into tissues and the use of these dietary nutrients to fuel metabolism Concepts discussed What are Stable Isotopes? How nutrients are stored in the body for future use (fat and glycogen) How nutrients are mobilized to meet energy demands What does the C in the CO2 we exhale tell us about the metabolic fuels we are burning What do animals tell us about our own physiology Materials (provided) 500ml nalgene bottle fitted with a scotch tape one-way stopcock valve LabconCo gas collection vials kimwipes Black sharpie Kool Aid Beet Sugar Cane Sugar 10 House Sparrows Students Methods Students At the beginning of class students will breathe into CO 2 collection vials to determine the time zero isotope composition of each students CO 2. Students will then drink one cup of Kool Aid. Half of the class will drink Kool Aid made with beet sugar (C3) and the other half Kool Aid made with cane sugar (C4). Every 15 minutes for one hour a sub-sample of students from each group (C3 or C4) will breath into CO2 collection tubes. From this we can determine the time from ingestion, absorption, to utilization as a metabolic fuel. Tubes will be sealed and analyzed at UW. The data will be returned to the students and posted on my website where they can review and talk about the results. Sparrows While students are absorbing sugars from the recently ingested kool aid, they will be collecting CO2 from house sparrows that have been raised on two different diets. The results will yield very different carbon isotope ratios in exhaled CO 2 . With assistance, individual house sparrows will be placed in a 500ml nalgene bottle for one minute. After one minute, a 50ml sample of air will be withdrawn by placing a syringe on the one-way stopcock valve. The gas sample will then be injected into a sealed CO2 collection vial. I will already have a dataset from this group of sparrows for the students to see in class the same day. This data set will then be used for class discussion about the results of the experiment.