A laboratory experiment is described in which students synthesize a variety of cationic gemini surfactants and analyze their efficacy as fabric softeners. Students perform a simple organic synthesis reaction and two analytical tests (one qualitative and one quantitative), and use the class data to assess the synthesized products. The experiment…

A laboratory inquiry into the thermochemical relationships in the reaction between aqueous solutions of NaHCO[subscript 3] and NaOH is described. The enthalpy change for this reaction, delta[subscript r]H, and that for neutralization of strong acid and NaOH(aq), delta[subscript n]H, are determined calorimetrically; the explanation for the…

The existence of solvated electrons has been known for a long time. Key methods for their production (i.e., photoionization of reducing ions, water radiolysis, and the reaction between H[middle dot] and OH[superscript -]) are unsuitable for most school laboratories. We describe a simple experiment to produce liquid ammonia and solvated electrons…

A two-period organic laboratory experiment that includes fluorescence sensing is presented. The pH-sensitive sensor MorphFl is prepared using a Mannich reaction between a fluorescein derivative and the iminium ion of morpholine. During the first laboratory, students prepare MorphFl. The second session begins with characterizing the sensor using…

Exopolysaccharide (EPS) production by the rhizobacterium "Sinorhizobium meliloti" is essential for root nodule formation on its legume host (alfalfa), and for establishment of a nitrogen-fixing symbiosis between the two partners. Production of EPS II (galactoglucan) by certain "S. meliloti" strains results in a mucoid colony…

In this laboratory exercise, students develop a LabVIEW-controlled high-performance liquid chromatography system utilizing a data acquisition device, two pumps, a detector, and fraction collector. The programming experience involves a variety of methods for interface communication, including serial control, analog-to-digital conversion, and…

Understanding stereochemistry is an important and difficult task for students to master in organic chemistry. In both introductory and advanced courses, students are encouraged to explore the spatial relationships between molecules, but this exploration is often limited either to the lecture hall or the confines of the library. As such, we sought…

Used since the time of the ancient Egyptians as a method for transferring liquids from one vessel to another, the siphon is a dependable tool. Although, the act of siphoning beer from a fermentation barrel or wine from a demijohn is a skill that has been passed down from generation to generation, do we really know how the siphon works? It is…

The surfaces of mammalian cells are coated with complex carbohydrates, many terminated with a negatively charged "N"-acetylneuraminic acid residue. This motif is specifically targeted by pathogens, including influenza viruses and many pathogenic bacteria, to gain entry into the cell. A necessary step in the influenza virus life cycle is the…

Demonstrating how surface chemistry and self-assembled monolayers (SAMs) control the macroscopic properties of materials is challenging as it often necessitates the use of specialized instrumentation. In this hands-on experiment, students directly measure a macroscopic property, the floatation of glass coverslips on water as a function of…

This article presents two integrated laboratory exercises intended to show students the role of [alpha]-amylases (AAMYs) in saliva and detergents. These laboratory practicals are based on the determination of the enzymatic activity of amylase from saliva and different detergents using the Phadebas test (quantitative) and the Lugol test…

Cell-free protein synthesis (CFPS) has emerged as a practical method for producing a broad variety of proteins. In addition, the direct accessibility to the reaction environment makes CFPS particularly suitable as a learning vehicle for fundamental biological concepts. Here, we describe its implementation as a teaching tool for a high school…

Dynamic light scattering (DLS) analyses are routinely used in biology laboratories to detect aggregates in macromolecular solutions, to determine the size of proteins, nucleic acids, and complexes or to monitor the binding of ligands. This article is written for graduate and undergraduate students with access to DLS and for faculty members who…

An interdisciplinary approach to education has become more important in the development of science and technology, which requires universities to have graduates with broad knowledge and skills and to apply these skills in solving real-world problems. An interdisciplinary experimental series has been developed for the laboratories in cell and…

Single and double electromagnetically induced transparencies (EIT) in a medium, consisting of four-level atoms in the inverted-Y configuration, are discussed using mechanical and electrical analogies. A three-coupled spring-mass system subject to damping and driven by an external force is used to represent the four-level atom mechanically. The…