This article presents a tangible model used to help students tackle some misconceptions about enzyme actions, particularly the induced-fit model, enzyme-substrate complementarity, and enzyme inhibition. The model can simulate how substrates induce a change in the shape of the active site and the role of attraction force during enzyme-substrate…

A laboratory experiment was developed to target analytical chemistry students and to teach them about insecticides in food, sample extraction, and cleanup. Micro concentrations (sub-microgram/mL levels) of 12 insecticides spiked into apple juice samples are extracted using liquid-liquid extraction and cleaned up using either a primary-secondary…

This work examines the feasibility of employing a Nintendo Wii game controller for measuring car speed in an interdisciplinary school project. It discusses the physical characteristics of the controller and of vehicle headlights. It suggests how an experiment may be linked to topics in mathematics, statistics, physics and computer science. An…

The phenomenon of interference has great importance in understanding the wave properties of light. Here, we demonstrate the effect of a moving reference frame on an interference pattern by building a simple Sagnac interferometer, without the burden of using optical fibres. A generalized theoretical derivation for an arbitrarily shaped…

For physical measurements, the compositions of solutions, especially electrolyte solutions, are expressed in terms of molality rather than mole fractions. The development of the necessary thermodynamic equations directly in terms of molality is not common in textbooks, and the treatment in the literature is not very systematic. We develop a…

Unlike most spectroscopic calibrations that are based on the study of well-separated features ascribable to the different components, this laboratory experience is especially designed to exploit spectral features that are nearly overlapping. The investigated system consists of a binary mixture of two commonly occurring minerals, calcite and…

Measurements are presented on the rise of a spinning egg. It was found that the spin, the angular momentum and the kinetic energy all decrease as the egg rises, unlike the case of a ballerina who can increase her spin and kinetic energy by reducing her moment of inertia. The observed effects can be explained, in part, in terms of rolling friction…

Pressure increases rapidly with depth in a water body. Ocean and Great Lakes scientists often use this physical feature of water as the basis of a fun pastime performed aboard research vessels around the world: the shrinking of polystyrene cups. Depending on the depth to which the cups are deployed, the results can be quite striking! Capitalizing…

In the present article, we describe a 3-day experimental workshop on type I diabetes aimed at helping high school students to understand how fundamental research on glycemia regulation contributes to the development of scientific knowledge and therapeutic strategies. The workshop engaged students in open-ended investigations and guided…

The authors examined college students' perceptions about their middle school and high school preparation for college science courses as well as what led them to study or not study science in college. Analysis of a survey using mixed methods revealed that the more laboratory techniques students felt proficient in conducting and the more science AP…

A medium-scale quantitative study (n = 90) found that 10-11-year-old pupils dealt with theory and evidence in notably different ways, depending on how the same science practical task was delivered. Under the auspices of a 2×2 part-randomised and part-quasi experimental design, pupils were asked to complete a brief, apparently simple task involving…

Graphene's unique combination of exceptional mechanical, electronic, and thermal properties makes this material a promising candidate to enable next-generation technologies in a wide range of fields, including electronics, energy, and medicine. However, educational activities involving graphene have been limited due to the high expense and…

Science textbooks and classes mostly emphasize what are considered by today's standards the "right" or "correct" interpretations of particular phenomena or processes. When "incorrect" ideas of the past are mentioned at all, it is simply to point out their errors, with little attention as to why the ideas were put…

The Electrochemical Pen (EChemPen) was developed as an attractive tool for learning electrochemistry. The fabrication, principle, and operation of the EChemPen are simple and can be easily performed by students in practical classes. It is based on a regular fountain pen principle, where the electrolytic solution is dispensed at a tip to locally…

The speed of sound in a solid is determined by the density and elasticity of the material. Young's modulus can therefore be calculated once the density and the speed of sound in the solid are measured. The density can be measured relatively easily, and the speed of sound through a rod can be measured very inexpensively by setting up a longitudinal…