Supplies procedure, testing questions, and sample working graph for an activity in testing an operating principle of small gasoline engine. (MU)

Describes several approaches to handling the technical problems that arise in televising science experiments. The article is written in French and includes a short summary in English. (AA)

This experiment subjects bacteria in a food sample and an environmental sample to conditions of sublethal stress in order to assess the effectiveness of the agar overlay method to recover sublethally injured cells compared to direct plating onto the appropriate selective medium. (SAH)

Describes the construction and use of an inexpensive colorimeter that reliably estimates the phosphorus concentrations in water. Presents a two-step modification to an existing photometer. (SAH)

Describes a laboratory course that introduces students to chemistry using examples commonly encountered in the supermarket and on the dinner table. Acquaints students with simple chemical tasks that can be practiced at home, including the making of wine, ale, soap, cheese, and yogurt, and introduces them to the small-scale production of…

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)

Isotope substitution often affects the rate of an organic reaction and can be used to reveal the underlying mechanism. A series of experiments that use (super 1)H NMR to determine primary and secondary isotope effects, activation parameters, and the regioselectivity of butanone enolization are described.

An experiment using methyle methanethiosulfonate (MMTS) and phenylmethylsulfonyl flouride (PMSF) to specifically modify the cysteine and serine residues in the active sites of papain and subtilism respectively is demonstrated. The covalent modification of these enzymes and subsequent rescue of papain shows the beginning biochemist that proteins…

Various phenomena that are observed in the process of heating solid iodine in closed vessels at different pressures and temperatures are described. When solid iodine is heated in an evacuated ampoule where the pressure is less than 10(super -3), no noticeable color appears and immediate condensation of tiny iodine crystals is visible higher up on…

A convenient, inexpensive, environment friendly, and regioselective conversion of an aziridine to an oxazolidinone is developed by using iodide salt and CO[2] in water. A description is provided, on the way in which this series of experiments will show students how to change experimental conditions to obtain mainly one desired regiosomer of a…

The experiment involving enantiomeric resolution, as an illustration of chiral technology, is an excellent early organic chemistry lab experiment. The success of this enantiomeric resolution can be judged by melting point, demonstrated by [plus or minus]-mandelic acid-(1R,2S)-(--)-ephedrine system.

Drosophila melanogaster is a popular organism for studying genetics and development. Maintaining Drosophila on medium prepared with varying concentrations of beer and evaluating the effects on reproduction, life cycle stages and other factors is one of the exercises that is versatile and applicable to many student levels.

The spectrophotometric method assists in the study of potassium permanganate-oxalate reaction. Basic analytical techniques and rules are implemented in the experiment, which can also include the examination of other compounds oxidized by permanganate.