Explains the redux chemistry of the experiment of cleaning pennies with a vinegar-salt solution. (Contains 12 references.) (YDS)

Uses DNA laboratories to apply three different active learning strategies to undergraduate education: (1) teaming students; (2) opening laboratories; and (3) linking experiments. Discusses the effectiveness of the stream method on student attitudes and understanding. (YDS)

Summarizes the recent research on pollen germination and introduces some basic studies on pollen tube growth that can be conducted in a secondary school laboratory. Discusses the use of a light microscope and refrigerator to study pollen. (Contains 13 references.) (Author/YDS)

Rx values in thin-layer chromatography (TLC) depend strongly on the solvent saturation of the atmosphere above the liquid in the TLC developing chamber. Presents an experiment illustrating the potentially dramatic effects on TLC Rx values of not equilibrating the solvent atmosphere during development. (ASK)

Presents a science activity focusing on student ideas about plants and builds a terrarium based on students' ideas about the conditions of plant growth and cycling. (YDS)

Explains a health science activity concerning Howard Florey's experiment and the discovery of penicillin. Uses a mouse's point of view to conduct the activity and asks students to present information about Florey's research as if a participating mouse is talking. (YDS)

In Hamlet, Shakespeare invites readers to ponder a famous philosophical question: To be or not to be? That is the question. In this issue, two trade books invite students to explore the question: To sink or not to sink? That is the experiment. Though both books are targeted for younger children, teachers can use these books with elementary…

We present a two-part undergraduate laboratory exercise. In the first part, electron transport in bovine heart submitochondrial particles causing reduction of cytochrome c is monitored at 550 nm. Redox-active dyes have historically been used in most previous undergraduate laboratory exercises of this sort but do not demonstrate respiratory…

The main objective of this class experiment is to show the influence of carbon source and of different fluoride concentrations on the biofilm formation by the bacterium "Streptococcus mutans." The observation of different biofilm morphology as a function of carbon source and fluoride concentration allows an interesting discussion regarding the…

The main objective of this class experiment is to measure the activity of two metabolic enzymes in crude extract from bird pectoral muscle and to relate the differences to their mode of locomotion and ecology. The laboratory is adapted to stimulate the interest of wildlife management students to biochemistry. The enzymatic activities of cytochrome…

This article reports the results of a recent study to evaluate the usefulness of physical models of molecular structures as a new tool with which to teach concepts of molecular structure and function. Of seven different learning tools used by students in this introductory biochemistry class, the use of the physical models in a laboratory was rated…

A practical experiment on the PCR is described that has been used over several years as part of an undergraduate biochemistry and molecular biology course for chemistry students. In the first experimental session, students prepare their own DNA samples from epithelial cells of the mouth and use them as templates in the PCR. In the second session,…

An experiment developed from the Advanced Integrated Environmental Laboratory illustrates the differences in automobile exhaust before and after the engine is warmed, using gas-phase Fourier transform infrared spectroscopy (FTIR). The apparatus consists of an Avatar 360 FTIR spectrometer from Nicolet fitted with a variable path length gas cell,…

The various features of a Visual Basic Program, which implements the 1672 Parr thermometer are described. The program permits remote control of the calorimetry experiment and also provides control for the flow of data and for file storage.

Many experiments have shown that the human visual system makes extensive use of contextual information for facilitating object search in natural scenes. However, the question of how to formally model contextual influences is still open. On the basis of a Bayesian framework, the authors present an original approach of attentional guidance by global…