1. BioEd Online Food and Fitness Virtual Workshop Activity One: Energy for Life by Nancy Moreno, PhD, and Paula Cutler, BS Baylor College of Medicine

2. www.BioEdOnline.org BioEd Online Energy for Living Organisms All living things require a source of energy. Producers make sugars and other carbohydrates (food) from water and carbon dioxide in the presence of light energy (photosynthesis). Consumers (listed below) rely on producers, such as green plants, for food. Animals Fungi Other non-photosynthetic organisms Sugars are small molecules made of carbon, hydrogen and oxygen. Energy in sugar is trapped in the chemical bonds between atoms. Glucose, the sugar molecule depicted above, is the initial product of photosynthesis. H O HC OH C H C OH HC OH CH 2 OH H BioEd Online

3. www.BioEdOnline.org BioEd Online Activity One: Predict What do you think will happen when: Yeast is combined with water? Yeast is combined with water and sugar? Saccharomyces cerevisiae Common baking and brewing yeast BioEd Online

4. www.BioEdOnline.org BioEd Online Set Up the Experiment Label two 250 mL containers: Sugar and No Sugar. Measure 50 mL water into each container. Add 1 packet of rapid rising yeast to each container. Add 2 teaspoons of sugar to the container labeled Sugar. Use separate spoons or stirrers to mix the contents of each container. Each group of students also will need: small metric ruler; sheet of graph paper; and copy of Is It Alive? student sheet. OPTIONAL thermometer or temperature probe BioEd Online

5. www.BioEdOnline.org BioEd Online Make Observations Record the starting and ending temperatures (degrees C). Observe the following characteristics of each mixture at five-minute intervals. Appearance Height of the liquid plus foam, if present (measure from bottom of container to top of foam) BioEd Online

6. www.BioEdOnline.org BioEd Online Height in cm (from bottom of beaker) Height of Foam Sample Graph Activity One: Yeast Growth Yeast cells broke down sugar molecules to obtain energy. Carbon dioxide gas was released as waste (created foam at top of mixture). Changes in height of CO2 foam reflect growth and resource use by yeast cells. Yeast without an energy source grew very little. Heat also was released. Mixture with sugar may become warmer by 1–3 degrees C. BioEd Online