Laboratory exercises for undergraduate biochemistry students are described in which changes in sugar content during fermentation of the trendy beverage kombucha are analyzed by three methods: thin layer chromatography, a 3,5-dinitrosalicylic acid assay, and a standard commercial blood glucose meter. Each of the three analyses can be completed in a…

In conventional e/m experiments performed in undergraduate laboratories, generally a simple mechanical ruler is used to measure the radius of the circular trajectory of the electrons. But, the measurement error in this technique is mostly big and varies from one student to another. As an alternative to a mechanical ruler, we proposed a more…

The cannon boring experiment of Count Rumford, where eight kilograms of water were boiled by metal on metal friction, is investigated. Consideration of this dramatic demonstration can enrich classroom discussions of calorimetry, units of measure, elements, and thermodynamics. A section pertaining to use of the article in the classroom appears…

Here, students determine the total phenolic content in beers using the Folin-Ciocalteu assay. The Folin-Ciocalteu reagent is a yellow complex, in an alkaline medium; it reacts with phenols and non-phenolic reducing substances to form a blue complex. Quantitative analysis was carried out using absorbance measured at 765 nm (standard method) and…

Open-ended and inquiry-based experiments will make students more active in the learning environment, and so they play an active role in solving the problem. So, it is expected that especially classroom teachers will be more active in the laboratory environment. In this context, opinions of the classroom teachers about the science laboratory…

An inquiry-based laboratory learning unit was designed to enhance high school students' understanding of the application of lipase as a catalyst to synthesize isoamyl and geranyl ester derivatives as well as to promote their understanding and positive perceptions of green chemistry. The learning unit consisted of three laboratories and a final…

One of the most general aims of universities is to respond to the requirements of society. Health and safety are the most important aspects of professional work and play an important role in universities, as there, future professionals are trained for their future professional life. Scientific and technical degrees require adaptation to this…

The Griess assay is widely used by regulation agencies as an official method for nitrite quantification in water and food samples. In Brazil, the official method, which has been used to determine nitrite in food, was described by Instituto Adolfo Lutz (283/IV) in 1984. It uses 8 mL of reactants and provides 50 mL (reactants plus sample) of waste…

Lampworking is a valuable skill for students in Chemistry and others in science, technology, engineering, and math (STEM) related fields. The activity described here provides instructors the resources to both learn and teach the fundamentals of lampworking. Soft glass, which can be shaped and fused with a Bunsen burner, is used to improve the…

This work shows the redesign of an elemental experience based on the Helmholtz resonator using 3D printing. A Helmholtz resonator is based on a volume and at least one opening that can include a tube or not. The air column inside the tube can be considered the mass of the system, whereas the volume represents the system's stiffness. Due to these…

The framework of ecosystem services (ES) and disservices (ED) has increasingly been used in various science, technology, engineering, and mathematics (STEM) disciplines, including soil science. The objectives of this study were to use ES/ED concepts to extend and test an existing lecture and laboratory exercise on soil organic carbon (SOC) in an…

Laboratory practical sessions are critical to scientific training in biology but usually fail to promote logical and hypothesis-driven reasoning and rely heavily on the teacher's instructions. This paper describes a 2-day laboratory practicum in which students prepare and analyze larval cuticle preparations of "Drosophila" segmentation…

Optical polarization phenomena are omnipresent in physics, chemistry, biology, and technology. Studying optical polarization is best done through an interdisciplinary approach that combines biology and technology, which usually makes things more interesting to students. Seeing Haidinger's brush for the first time can be an exciting discovery for…

For science students doing traditional laboratory experiments, often it may feel as if the apparatus and experiment have been specifically chosen for good results. They suspect that the science they are learning in the classroom will not match nearly as well in the real world. However, many educators have observed that student motivation and…

A quantitative titration of the amount of magnesium hydroxide in milk of magnesia using only items purchased in grocery and retail stores is reported. Either vinegar or a solution of food grade citric acid serves as the titrant, while food dyes advertised as being extracted from natural sources provide the end-point indicator. An inexpensive,…