Energy comes in many forms, but how do living things get the energy they need to survive and thrive? In a simple, controlled experiment with yeast, water, and sugar, groups make observations about how yeast reacts with water alone, then with water and sugar. Learners record the data they collect on the worksheet provided, then write a paragraph describing their observations. The first of a seven-lesson unit on energy and life, these activities lay the groundwork for the next lesson: energy sources.