Food is a universal theme that can be used to integrate all areas of the curriculum; from social studies to math, from biology to chemistry. As a means of engaging your students all that you need to do is ask what is one type of food they eat at home that they never eat in public. That is exactly what I did with my students, and to my astonishment; they mentioned meals that I never had heard of before. Of course, my students may not be representative of the majority of the students in the district where I teach. As an English Language Learner (ELL) instructional coach, I serve a population of new immigrants and second-generation students for whom food is yet another indicator, with language and customs, of significant cultural values that singles them out from the rest.
The topic of food allows for many hands on activities related to how the changes in matter affect the chemical composition of a substance and the chemical changes that take place in the conversion of food from raw materials into energy via the process of preparation (as simple as washing and drying an apple), elaboration (creating a menu with apples as the feature ingredient), to processing (making apple juice), to cooking (making an apple pie), to consumption, and discharge.
However, this unit explores the way that certain microorganisms have assisted human kind to progress through the ages, the ways they are currently used in cooking and other science fields, and what they have to offer to today's civilization as model systems. One of these microorganisms Saccharomyces cerevisiae, otherwise know as baker's yeast, has been used as a model system for the exploration in genetics and cell biology. This is the case because it is a unicellular organism with important similarities to the cell cycle in humans, as well as because of it easy genetic manipulation.
This unit is centered on some microorganisms that through the ages have been used to prepare, create, or assist in the processing of foods so that they can be consumed. As this unit explores these organisms and their interactions before, during, or after cooking, some of the basic chemical principals involved in the process are explained. Among these microorganisms that are discussed we have yeasts and helpful bacteria and enzymes used in the creation of cheese, yogurt, or miso.
As we explore the way that common foods such as pancakes, bread, muffins, and common drinks such as ginger-ale, soda, or carbonated water; we will explore the chemical reactions originated by a very special yeast: Saccharomyces cerevisiae and we will compare it to other microorganisms used in making breads and quick breads based on sourdough starters and on leavening substances such as baking soda and baking yeast.