Chlorophyll, the most abundant pigment in nature, is degraded during normal plant growth, when leaves change color, and at specific developmental stages. Chlorophyllase catalyzes the first chemical reaction in this process, that is, the hydrolysis of chlorophyll into chlorophyllide. Here, we describe a series of laboratory sessions designed to…

Comprehensive measurement of gene expression using high-density nucleic acid arrays (i.e. microarrays) has become an important tool for investigating the molecular differences in clinical and research samples. Consequently, inclusion of discussion in biochemistry, molecular biology, or other appropriate courses of microarray technologies has…

Since 2002, the PhET Interactive Simulations project at the University of Colorado has been working to provide learning tools for students and teachers. The project has developed over 85 interactive simulations--or sims--for teaching and learning science. Although these sims can be used in a variety of ways, they are specifically designed to make…

We present an immersive virtual reality (VR) application for physics education. It utilizes a recent physics engine developed for the PC gaming market to simulate physical experiments correctly and accurately. Students are enabled to actively build their own experiments and study them. A variety of tools are provided to analyze forces, mass, paths…

Useful materials for science projects are described (CK)

Research is a process by which people discover or create new knowledge about the world in which they live. The International Science and Engineering Fair (ISEF) and Affiliated Fairs are research (data) driven. Students design research projects that provide quantitative data through experimentation followed by analysis and application of that data.…

In this paper we describe and discuss simple, inexpensive optical experiments used to simulate x-ray and electron diffraction according to the Debye-Scherrer theory. The experiment can be used to address, at the high school level, important subjects related to fundamental quantum and solid-state physics.

The widely used PASCO laboratory equipment is an excellent way to introduce students to many topics in physics. In one case, PASCO's equipment may be too good! Various experiments exist for calculating the kinetic coefficient of friction by measuring the acceleration of a sliding object under some constant force. With ever more accurate equipment,…

Human walking is a complicated motion. Movement scientists have developed various research methods to study gait. This article describes how a high school student collected and analysed high quality gait data in much the same way that movement scientists do, via the recording and measurement of motions with a video analysis tool and via…

Biology teachers know how important it is for them and for their students to engage first-hand with nature. Ideally, bringing students to fields, woodlands, and wetlands to observe, explore, and wonder is the best way to stimulate curiosity and practice scientific inquiry. However, for many reasons, field excursions are not always practical or…

This lab experiment illustrates the use of differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA) in the measurement of polymer properties. A total of seven exercises are described. These are dry exercises: students interpret previously recorded scans. They do not perform the experiments. DSC was used to determine the…

We have optimized a procedure for igniting hydrogen-filled balloons containing metal salts to obtain the brightest possible flash while minimizing the quantity of airborne combustion products. We report air quality measurements in a lecture hall immediately after the demonstration. While we recommend that this demonstration be done outdoors or in…

An experiment for the undergraduate quantitative analysis laboratory involving applications of visible spectrophotometry is described. Salicylate, a component found in several medications, as well as the active by-product of aspirin decomposition, is quantified. The addition of excess iron(III) to a solution of salicylate generates a deeply…

We present a first-principles determination of the photoelectron spectra of water and hypochlorous acid as a laboratory exercise accessible to students in an undergraduate physical chemistry course. This paper demonstrates the robustness and user-friendliness of software developed for the Franck-Condon factor calculation. While the calculator is…

This article describes the rapid, green synthesis of a biaryl compound (4-phenylphenol) via a Pd(0)-catalyzed Suzuki cross-coupling reaction in water. Mild reaction conditions and operational simplicity makes this experiment especially amenable to both mid- and upper-level undergraduates. The methodology exposes students to purely aqueous…