Dilute guarana´ ("Paullinia cupana") powder aqueous extract is a soft drink that contains three structurally related methylxanthines (MXs), caffeine (CF), theobromine (TB), and theophylline (TP); CF is present in a large excess. Literature data show that values of [lambda][subscript max] and [epsilon][subscript max] of these three MXs…

Why do we need to pour less water in an egg steamer to prepare more eggs to the same degree of 'doneness'? We discuss the physical processes at work in the electric egg steamer and resolve this seeming paradox. We demonstrate that the main heat transfer mechanism from steam to egg is due to latent heat through condensation. This not only explains…

This article describes a simple way to introduce nanomaterials using the presence of carbon nanodots (CNDs) in widely available food. Budweiser® beer and Coca-Cola®, commercial foods that are commonly accessible, were utilized to demonstrate the optical property of nanoparticles. Specifically, green and violet laser pointers were employed for the…

NMR spectroscopy is traditionally taught to students during Organic Chemistry as a tool used for the determination of structures after synthesis. However, modern NMR spectroscopy has many important applications beyond structure elucidation, including molecular profiling of complex mixtures as biofluids and food samples. In this experiment,…

This article argues that we need to make use of our everyday experiences when introducing concepts in chemistry that are often obscure. It uses reaction rates as an example and explores a common misconception related to the explanation of the effect of rising temperature on the rate of slow reactions.

This article presents and discusses the results of an educational innovation that seeks to introduce the world of molecular gastronomy in chemistry lessons as a means to review stoichiometry and offer an alternative way to learn. In the literature to date, there is no evidence of haute cuisine having been employed to contextualize stoichiometry…

Context-Based Learning (CBL) and learning through developing and using models are two important teaching approaches for chemistry conceptual understanding. We aimed to examine the influence of a CBL approach on students' understanding of Multiple Models of Knowledge Representations ("MMKRs") and "multiple molecular…

Training "Aplysia" with inedible food for a period that is too brief to produce long-term memory becomes effective in producing memory when training is paired with a nitric oxide (NO) donor. Lip stimulation for the same period of time paired with an NO donor is ineffective. Using qPCR, we examined molecular correlates of brief training…

Using pharmacologic and genetic approaches targeting actin or the actin-driving molecular motor, nonmuscle myosin II (NMII), we previously discovered an immediate, retrieval-independent, and long-lasting disruption of methamphetamine- (METH-) and amphetamine-associated memories. A single intrabasolateral amygdala complex infusion or systemic…

Habituation is a highly conserved phenomenon that remains poorly understood at the molecular level. Invertebrate model systems, like "Caenorhabditis elegans," can be a powerful tool for investigating this fundamental process. Here we established a high-throughput learning assay that used real-time computer vision software for behavioral…

A variety of fruits and vegetables, including raspberries, blueberries, Concord grapes, blackberries, strawberries, peaches, eggplant, red cabbage, and red onions, contain flavonoid compounds known as anthocyanins that are responsible for the blue-red color and the astringent taste associated with such foods. In addition, anthocyanins exhibit a…

The experiment proposed here illustrates some concepts of tomography via a qualitative determination of the relative concentration of various dilutions of food dye without "a priori" knowledge of the concentration of each dye mixture. This is performed in a manner analogous to computed tomography (CT) scans. In order to determine the…

This paper reports a laboratorial internship included in the Portuguese Science and Technology promotion program "Internships for Young People in Laboratories (Ciência Viva no Laboratório)", which provided high school students an opportunity to approach the reality of scientific and technological research in a higher education…

Identification of macromolecules in food is a standard introductory high school biology lab. The intent of this article is to describe the conversion of this standard cookbook lab into an inquiry investigation. Instead of verifying the macromolecules found in food, students use their knowledge of the macromolecules in food to determine the…

This article describes an interrupted case study that intersperses information about diffusion and osmosis with content review and knowledge application questions, as well as a simple experiment that can be conducted without the use of a laboratory. The case study was developed for use in an introductory undergraduate biology course. The case…