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.

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.

A chemical laboratory information profile (CLIP) of the chemical chlorine, produced in small quantities in the laboratory, is presented. The profile summarizes physical and harmful properties, exposure limits, reactivity risks, and symptoms of major exposure for the benefit of teachers and students using the chemical in the laboratory.

The analytical system to teach the subtleties of assaying alpha-dicarbonyl compounds in wine is described. Spectrophotometry is determined to be minimally useful in the experiment where the GC-MS (methyglyoxal) method proved to be ideal to confirm that the compounds analyzed in the wine samples were indeed the glyoxals based on the formation of…

A crucial element of the logic of the scientific method is the Control of Variables Strategy (CVS), in which conclusions about causal relations are enabled by manipulating a focal variable of interest while holding all other variables constant. Understanding CVS in elementary grades generally is poor, but can be improved with systematic…

In response to a direct request from science teachers, researchers initiated a pilot experience on animal orientation and navigation, which was delivered to 61 13-year-old students in Florence, Italy. The aim was to explain the approach to ethology and to link animal navigation with geography, focusing on species crossing the Italian territory.…

This paper describes a study intended to demonstrate how an emerging skill, problem solving with technology, might be measured in the National Assessment of Educational Progress (NAEP). Two computer-delivered assessment scenarios were designed, one on solving science-related problems through electronic information search and the other on solving…

In the goal of science teacher education, the role of reflection to cultivate the teacher as a transformative practitioner has been largely recognised. Reflective thinking is crucial for teachers to be mindfully and knowledgeably situated in teaching and transforming their actions. This study looks into the dilemmas of teaching practical work in…

Current trends in ecological research emphasize interdisciplinary approaches for assessing effects of present and predicted environmental changes. One such emerging interdisciplinary field is the discipline of ecohydrology, which studies the feedbacks and interactions between ecological and hydrological processes. However, interdisciplinary…

Describes an experimental method of measuring the molecular weight and subunit corporation of an oligomeric protein. (SL)

Describes a geology laboratory exercise involving weathering and topographic maps which allows students to put knowledge to practical application. (SL)

Describes a simple chemistry laboratory experiment which allows students to calculate thermodynamic values. (SL)