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. Each student adds a small amount of baking yeast to a test tube filled with diluted molasses. Then a second, smaller test tube is placed upside-down inside the solution. As the yeast cells respire, the carbon dioxide they produce is trapped inside the inverted test tube, producing a growing bubble of gas that is easily observed and measured. Students are presented with the procedure for designing an effective experiment; they learn to think critically about experimental results and indirect observations of experimental events.
Bubbles floating.Copyright http://webs.wichita.edu/facsme/elecbub.htm
Concepts covered in this activity are used in biomedical, chemical and environmental engineering. This activity also includes elements of biotechnology, applications of experimental and analytical techniques in living systems, food processing and processes of nature.
After this activity, students shouuld be able to:
- Compare and contrast cellular respiration in yeast vs. plant and animal cells.
- Describe the role of yeasts in the production of bread and alcoholic beverages.