Although instruction on meiosis is repeated many times during the undergraduate curriculum, many students show poor comprehension even as upper-level biology majors. We propose that the difficulty lies in the complexity of understanding DNA, which we explain through a new model, the DNA triangle. The "DNA triangle" integrates three…

Describes the nature and capabilities of methods used to characterize protein and peptide structure, indicating that they have undergone changes which have improved the speed, reliability, and applicability of the process. Also indicates that high-performance liquid chromatography and gel electrophoresis have made purifying proteins and peptides a…

Surveyed are the etymology and the reason scientists coined a specific name for a newly discovered element. Approaches to naming from a historical viewpoint are considered. (CW)

Discussed is an analytical technique that uses photons from lasers to resonantly excite an electron from some initial state of a gaseous atom through various excited states of the atom or molecule. Described are the apparatus, some analytical applications, and the precision and accuracy of the technique. Lists 26 references. (CW)

The story of researcher Joseph V. Smith's solution to the chemical structure of a zeolite known as boggsite is presented. The value of the solution and the use of boggsite are discussed. (CW)

Described is research conducted on cluster-assembled matter. The differing character of these arrangements of matter are discussed. Methods used to produce clusters are reviewed. (CW)

Outlined is a method for collecting and cutting oriented samples for microstructural analysis including handling the samples in the laboratory, cutting and orienting chips parallel to the motion plane, and cutting and orienting chips normal to Le and foliation. (CW)

Advocates the teaching of quantum chemical ideas to undergraduates. Discusses the total failure of the electronegativity approach and comparison with other theoretical approaches. (CW)

Describes a simple method to teach molecular geometry using styrofoam balls and velcro strips. Discusses the construction and a procedure for using the model for teaching. (CW)

Provides an introduction to and summaries of the manufacturing methods and uses of chemicals 51-75 on the list of chemicals arranged in order of decreasing production in the United States. Gives production in pounds, annual growth, average price per pound, and organization according to the seven basic organic chemicals. (CW)

Presented is a technique for making various molecular models from a strip of paper. Instructions for six models including tetrahedral, trigonal bipyramid, octahedral, pentagonal bipyramid, and capped octahedron models are provided. (CW)

Detailed is a method in which short pieces of teflon tubing may be used for collection tubes for collecting preparative fractions from gas chromatographs. Material preparation, laboratory procedures, and results of this method are discussed. (CW)

Discussed are the mechanisms of nuclear magnetic relaxation, and applications of relaxation times. The measurement of spin-lattice relaxations is reviewed. It is stressed that sophisticated techniques such as these are becoming more important to the working chemist. (CW)

Examined are the illustrations and descriptions of the molecular structure of sulfur dioxide found in selected chemistry textbooks. Inconsistencies and incorrect information are indicated. It is suggested that molecules other than sulfur dioxide be used as examples of molecules for which resonance is important. (CW)

Applications of lasers to molecular absorption spectrometry, molecular fluorescence spectrometry, visible semiconductor fluorometry, atomic absorption spectrometry, and atomic fluorescence spectrometry are discussed. Details of the use of the frequency-doubled diode laser are provided. (CW)