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To promote understanding of the authority of the primary literature in students taking our biochemistry laboratory courses, a biochemistry laboratory exercise on the determination of an acceptable molar absorptivity value of 2-nitrophenol (2-NP) was developed. This made the laboratory course much more relevant by linking to a thematic thread, [beta]-galactosidase, that scaffolds concepts in one exercise with those in later exercises. The substrate for the continuous assay of [beta]-galactosidase is the chromogenic 2-nitrophenyl-[beta]-D-galactopyranoside that produces 2-NP. In an early laboratory exercise, students determine the wavelength of maximum absorption for the protonated and deprotonated form of 2-NP at various pH values and then determine the molar absorptivity of 2-NP. Students were encouraged to discuss apparent discrepancies not only in their own determinations of molar absorptivity values for 2-NP, but also in the published molar absorptivity values for 2-NP (2,150-21,300 M[superscript -1] cm[superscript -1]) at almost the same pH and at 420 nm. Finally, the students were led to a publication that serves as an authentic source for molar absorptivity of 2-NP. (Contains 3 figures, 2 tables, and 1 footnote.)

Students' reactions to classroom learning and the mastery of science vary along a wide spectrum of attitudes and emotions. In particular, we argue here that how learners encounter and learn subject matter is a function of their level of cognitive development. We describe the stages of cognitive development based on the work of William Perry and demonstrate their relevance to the undergraduate science classroom. With examples drawn from biochemistry, we attempt to show that, depending on the student's developmental level, there will be different abilities to handle the range of assignments and activities s/he can expect to experience in the average classroom. The college science instructor can benefit from knowledge of these stages and can work through their implications to develop strategies and techniques to regulate collective student learning.

The theory of memory and the ability to influence learning with conscious and unconscious factors, both internal and external, is reviewed. From a connectionist view of memory, the interactive compensatory model of learning is introduced, with an emphasis on the plastic components (motivation, prior knowledge, and metacognition) that can be regulated. Expert students, but not naive students, have a considerable ability to self-regulate their learning processes and improve performance in undergraduate courses. We propose that in a class situation, there are emergent opportunities for an instructor who understands the dynamics of the learning environment to provide regulation for collective learning of multiple students and improve group learning. There are three interfaces for instructor-regulated collective learning, and examples are provided for each to suggest how instructors may effectively provide regulation.

The discussion board feature that is included with most course management software packages is a potentially valuable tool to augment instructor-student interactions in science lecture courses and increase student motivation. However, many teachers seem to have been frustrated that students do not readily make use of this feature when it is added to the course resources. The author has been using a discussion board in undergraduate biochemistry lecture courses for six years and has learned to use it to evolve a system that students use and that seems to increase interaction with students while requiring less time than traditional face-to-face meetings outside of the lecture. The aspects that the author emphasizes for efficient discussion board use are timing, creating a safe virtual environment for the students, "seeding" with simulated questions, setting boundaries, and being self-conscious about the attitude that the instructor projects to the students.

Describes the development of three graduate level biochemistry courses targeting high school science teachers. Uses distributed resources and points out the lack of certainty on such freely available distributed resources. (Author/YDS)

Describes the operation of the Minolta SPAD-502 Leaf Chlorophyll meter. Presents five sample activities for using this technology in high school or college science classes. (WRM)

Student motivation is correlated with learning. Douglas McGregor's Theory X and Theory Y as a basis for understanding and improving motivation in the business world can be directly applied to the science classroom. Teachers with a Theory Y perspective (students naturally want to learn) provide increased motivation for students and promote more active learning than Theory X-style teachers who do not view students as active learners. Many teachers are not aware of their Theory X/Theory Y orientation and how this bias may be impacting their interaction with students. This article explores the benefits of moving from a Theory X to a more Theory Y style of teaching.

Chemistry students are better prepared for careers if they learn about the principles of polarity and chemical partitioning that underlie various kinds of chromatography. Principles are more or less the same for paper chromatography, high-pressure liquid chromatography (HPLC) and thin-layer chromatography (TLC). In science education hands-on activities should illustrate principles. Plant materials, especially colorful leaves such as those of Coleus plants or fall leaves which had been green and then became red, can be used. In a Coleus leaf the pigments represent molecules with a wide range of polarities. First students see a demonstration that results in partitioning of pigments. Later they use their understanding to develop a system to separate different pigments using a rather inexpensive TLC system. They make their own developing solutions. Even advanced high school chemistry students can profit from these activities. The kind of polarity involved with chromatography is not the same kind generally referred to in organic chemistry classes. A football game/music analogy is suggested to help students understand partitioning.

Anthocyanin pigments are commonly used for pH indicators in chemistry courses because of their familiarity to students and their ability to stimulate students' interests in chemistry. Anthocyanins can also be used to explore other topics, such as chromatography, extraction and hydrolysis, to further capitalize on students' natural interests. These experiments are suitable for high school courses because good results are obtainable even when the sample is prepared during a previous class.

Fruit anthocyanins can be used to perform interesting, colorful chemistry demonstrations in secondary and undergraduate chemistry courses because they illustrate light absorption, acid-base equilibrium and other chemical principles. These molecules are responsible for various pigments including red and blue in some flowers and can be extracted from fruit or fruit juices such as cranberry juice. They can provide students with hands-on research and experimentation experience. Suggested experiments are included.

The problems associated with development and maintenance of web-based chemistry courses for high school teachers and students containing numerous hyperlinks is discussed. An easy method to add, remove and edit web-based content by using 'wiki', web software is also discussed.

The development and delivery of a series of Web-based content courses for in-service high school chemistry teachers, which could serve wide array of participants, are reviewed.

Cooperative, open-ended undergraduate biochemistry student activities involving candies can be used to promote understanding of electrophoretic fractionation on the part of those studying chemistry. Directed activities come first. This could be adapted to biology or general chemistry and even to high school. Students establish the Food, Drug and Cosmetic Identity (FD&C No.) of food dyes used in candy coatings. In the first part of the exercise they investigate electrophoretic mobility of two classes of natural pigments, anthcyanins and betacyanins. The are exploring how and why molecules may be fractionated by electrophoresis. M&Ms, licorice jelly beans, for the open-ended exercises, cranberry or grape juice and beer, which has betacyanin dye, can be acquired at most grocery stores.