This month a short two-lesson curricular unit entitled Cellular Respiration and Population Growth provides a hands-on activity for students to do learn about chemical engineering. The unit allows students to explore yeast and how it is used to make bread and alcohol. Yeast cells are readily obtained and behave predictably, so they are very appropriate to use in school classrooms. The unit is designed for grades 7 through 10 and provides an important opportunity to discuss the effects of alcohol on the body while also discussing science and chemical engineering.

In the first lesson, What do Bread and Beer have in Common?, students are introduced to yeast respiration through its role in the production of bread and alcoholic beverages. A discussion of the effects of alcohol on the human body is used both as an attention-getting device, and as a means to convey important information at an impressionable age. In the associated activity, Yeast Cells Respire, Too (But Not Like Me and You), students set up a simple way to indirectly observe and quantify the amount of respiration occurring in yeast-molasses cultures. Based on questions that arise from the first activity, in the second activity, How to Make Yeast Cells Thrive, students work in small groups to design and execute their own experiments to determine how environmental factors affect yeast population growth. Factors that students may decide to examine include temperature, food supply, and pH.

Unit: Cellular Respiration and Population Growth
Lesson 1: What do Bread and Beer have in Common?
Activity 1: Yeast Cells Respire, Too (But Not Like Me and You)
Lesson 2: Population Growth in Yeasts
Activity 2: How to Make Yeast Cells Thrive activity

This curricular unit is brought to you by the new Engineering Pathway, a part of the National Science Digital Library. The portal provides high-quality teaching and learning resources in applied science and math, engineering, computer science/information technology and engineering technology — for use by K-12 and university educators. The Engineering Pathway brings together quality engineering education materials from all over the internet allowing teachers to search all of these documents in a single location. The curricular unit is from the TeachEngineering Digital Library for K-12 engineering curricula.