In this article, we describe curricular materials developed to engage undergraduate students in evolutionary thinking around antibiotic resistance using the MEGA-plate experiment (Microbial Evolution and Growth Arena). This elegant and visual experiment, developed by the Kishony Lab, shows the development of antibiotic resistance on the timescale…

Rhizobacteria that colonize plant roots and promote plant growth are referred to as plant growth-promoting rhizobacteria, and this can stimulate plant growth either indirectly or directly. Volatile organic compounds (VOCs) emitted by rhizobacteria have the capacity to promote plant growth as well as perform biocontrol of fungal pathogens. The…

Enzyme kinetics is an essential topic in undergraduate Biochemistry courses. A laboratory work that covers the principal basic concepts of enzyme kinetics in steady state is presented. The alkaline phosphatase catalyzed reaction of phenyl-phosphate hydrolysis was studied as a model. The laboratory experience was designed to reinforce the concepts…

In this study, we made a simple electronic electroscope called a 'polarity detector' which can determine the type of electric charge on any objects. We used the polarity detector in some student experiments in the physics laboratory. For example, when we applied a plastic rod to a piece of fabric made of wool, we could easily determine that the…

A Microsoft Excel workbook has been developed to simplify the quantitative analysis of experimentally measured titration curves for diprotic and triprotic amino acids such as glycine, arginine, histidine, and glutamate. Students perform the titration, enter the data into the worksheet, and manually adjust the resulting pK[subscript a] values to…

Einstein's relation between mass and energy is perhaps the most famous equation of Physics. Despite its simplicity, the meaning of E[subscript 0] = mc[superscript 2] is not easy to grasp. Furthermore, its traditional derivations rely either on the integral of "momentum," on properties of electromagnetic radiation, or even on the…

When the thermal expansion of water is discussed in school or university lessons, functional relationships are often inferred without considering measurement uncertainties. Moreover, in some learning materials, the goal of experimentation and the experimental setup do not match. This creates the wrong picture of scientific practice. In this…

Previous work has highlighted the difficulties students have when explaining wave behavior. We present an investigation of chemistry students' understanding of the double-slit experiment, where students were asked to explain a series of PhET simulations illustrating a single continuous light source, single-slit diffraction, and double-slit…

Two misconceptions about the mechanism of image formation in the human eye are common among students and even in textbooks and other teaching materials. The first attributes all refraction to the eye lens; the second treats the eye as a pinhole camera. To reduce these persistent conceptions of students, a series of simple experiments is presented…

Understanding potentiometry is a difficult task when students in initial courses of Analytical Chemistry are first introduced to instrumental techniques. The closest instrument to them is a pH meter, which is frequently used as a "black box", without a real understanding of how it works. Here we present the assembly of jelly modules that…

Pulsed field gradient nuclear magnetic resonance (NMR) is used to estimate the size of quantum dots (QDs) produced in a simple, fast, small-scale synthesis. This upper-division laboratory experiment teaches the basics of QD synthesis and pulsed field gradient NMR, a powerful technique for measuring diffusion coefficients in solution. The diffusion…

There is an increasing need for fundamental electrochemistry concepts to be taught in the undergraduate curriculum, given the broad applicability of electrochemical technologies in addressing a wide range of global issues from critical energy shortages to real-time medical diagnostics. However, many electrochemical concepts are often taught in…

Demonstration interviews with 27 high school students (18-19 years old) were conducted in Zagreb, Croatia, using several standard experiments on interference and diffraction of light. Students were asked for their predictions, observations, and explanations of the experiments. In this process, many student difficulties were identified, both…

Thin-layer chromatography, which involves the movement of dyes along a silica-coated plate, is used to observe the progress of chemical reactions and to separate mixtures. We took advantage of this phenomenon to devise a method for generating patterns in the shape of numbers with dots (dot matrix). We prepared the azo dyes necessary for generating…

In this laboratory teaching experiment, commercial cannabis oils were analyzed by undergraduate organic chemistry students using gas chromatography-mass spectrometry (GC-MS) to investigate three isomeric cannabinoids commonly found in cannabis products: cannabidiol (CBD), [delta][superscript 9]-tetrahydrocannabinol ([delta][superscript 9]-THC),…