Describes an experiment that uses the ultrasonic transducer for demonstrating the Fourier components of waveshapes such as the square and triangular waves produced by laboratory function generators. (JRH)

Suggests specific ways in which laboratory activities might be slightly modified to increase students' understanding in science, based on recommendations from the National Science Education Standards and on constructivist understandings of the learning process. Contains 42 references. (WRM)

Presents suggestions for alternative presentations of some of the material that usually forms part of the introductory chemistry course. Emphasizes development of concepts from experimental results. Discusses electronic configurations and quantum numbers, experimental evidence for electron configurations, deducing the shell model from the periodic…

Presents an alternative approach to teaching reaction thermodynamics in introductory chemistry courses using calculations of enthalpies, entropies, and free energies of atomization. Uses a consistent concept, that of decomposition of a compound to its gaseous atoms, to discuss not only thermodynamic parameters but also equilibrium and…

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…

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,…

A simple tea infuser is obtained and been used as a container for the dry ice to simulate the effect from high-density dry ice. The tea infuser is a simple, low cost device to allow instructors with access to dry ice makers to effectively use the interesting demonstration.

An HPLC and a UV-visible spectrophotometer are identified as instruments that helps to incorporate more biologically-relevant experiments into the course, in order to increase the students understanding of selected biochemistry topics and enhances their ability to apply an analytical approach to biochemical problems. The experiment teaches…

Heavy faculty teaching loads and limited funds biology teachers designed certain objectives in order to increase the understandability of the subject matter of the laboratory exercises they write. In relation to these objectives an old "cookbook" laboratory exercise on yeast fermentation is introduced which involve students asking questions,…

The importance of introducing various projects or activities as a motivation towards inquiry-based learning, also satisfies the need for first year chemistry students to transfer scientific theory into practice. This approach, combined with the traditionally written laboratory methods, develops creative skills, and the spirit of exploration…

In this paper are presented the views of Al Haytham and his predecessors on the shadows, the rectilinear propagation of rays and the images produced by pinholes. Al Haytham had given erroneous views on the distribution of light in the shadows. Educational applications of these are presented. These applications concern: (a) Simple experiments (b)…

The activities that introduce topics of chemical health and safety are offered, using student-centered cooperative method. Teaching methods and exercises used in various activities were considered valuable enough to be modified and published in a book of activities for safety.

In this work, we describe the use of several strategies employing the philosophies of active learning and problem-based learning (PBL) that may be used to improve the teaching of metabolic biochemistry to medical and nutritional undergraduate students. The main activities are as follows: 1) a seminar/poster system in a mini-congress format (using…

Modeling has been shown to correct weaknesses of traditional instruction by engaging students in the design of physical models to describe, explain, and predict phenomena. Although the modeling method can be used without computers, the use of computers allows students to study problems that are difficult and time consuming, to visualize their…