Quantitation & Case-Study-Driven Inquiry to Enhance Yeast Fermentation Studies

Abstract

We propose a procedure for the assay of fermentation in yeast in microcentrifuge tubes that is simple and rapid, permitting assay replicates, descriptive statistics, and the preparation of line graphs that indicate reproducibility. Using regression and simple derivatives to determine initial velocities, we suggest methods to compare the effects of experimental variables. This technique is straightforward enough to facilitate design of an inquiry lab based on a scenario that explores modifications to enhance the rate of fermentation.

Using Yeast Fermentation as a Context for Meaningful Learning of Procedural Understanding

“…S8). Some setups may be prepared by the teacher in advance for the students to choose from, such as the setup proposed by Grammer (2012), which allows for assay replicates (leading to a discussion of issues related to repeatability). This stage provides a chance for students to assess different setups in terms of the validity and reliability of the data produced by the various setups, and the underlying reasons for differences in validity and reliability.…”

“…The teacher can also explicitly prompt discussion of concepts of evidence associated with measurement (e.g., accuracy, repeatability, choice of equipment) and the setup that can generate the most valid data. For example, the teacher may pose questions about the advantages of using Grammer's (2012) setup. This stage allows teachers to help students develop an understanding of concepts of evidence associated with measurement, such as relative scale, range and interval, choice of instruments, repeatability, and accuracy.…”

A Simple Microscale Setup for Investigating Yeast Fermentation in High School Biology Classrooms

“…Some involve the use of test tubes (Taylor, 1987;Johnson, 1998;Bartlett, 2002), others the use of burettes and pipettes (Yurkiewicz et al, 1989) and/or Erlenmeyer flasks (McElroy, 1976;Tatina, 1989). Still others make use of materials that are common in the contemporary molecular biology laboratory (e.g., 15 mL centrifuge tubes and Eppendorf tubes; Reinking et al, 1994;Grammer, 2012). The setup described here utilizes plastic transfer pipettes commonly found in molecular biology labs.…”

A Multiweek Project Examining the Chemotactic Behavior of Tetrahymena in an Undergraduate Biology Laboratory

“…The first module emphasizes biological molecules and concludes with a guided inquiry lab in which students design an experiment to investigate the effects of pH, temperature, and inhibitors on the activity of lactase (8). The second module introduces students to cell biology and concludes with a guided inquiry experience on yeast fermentation in which students examine the effects of time, concentration, and the nature of sugar on rates of fermentation (9). For the third module, we have designed a three-week project in which students investigate the chemotaxis of Tetrahymena and examine how changes in the environment and genetics influence the behavior of these cells grown in culture.…”