Introduces a laboratory experiment that isolates a bacterial polypeptide sample and measures the concentration of polypeptides in the sample. Uses Escherichia coli strain MM294 and performs a bio-rad assay to determine the concentration of polypeptides. (YDS)

Describes a method for determining the rate constants of enzyme reactions involving two substrates with the use of double reciprocal plots. (MLH)

Describes an easily-implemented experiment in which a moderately complex relation between dependent and independent variables is involved. (Author/GS)

Describes a freshman chemistry experiment designed to introduce scientific methodology, provide practice in measurement skills, and illustrate a fundamental chemical relationship (conservation of volume). Provides the experimental design, a materials and equipment list, sample calculations, and results. (JM)

Microcomputer-based laboratories (MBLs) are believed to have significant potential for improving laboratory experiences in science classrooms. A study funded through a grant project called STEPS to Better Science sought to broaden the knowledge base by examining MBL use by teachers and students in a variety of science classrooms in six high…