Enzymes are nature's catalysts, mediating chemical processes in living systems. The study of enzyme function and mechanism includes defining the maximum catalytic rate and affinity for substrate/s (among other factors), referred to as enzyme kinetics. Enzyme kinetics is a staple of biochemistry curricula and other disciplines, from molecular and…

An introductory guide to deducing the mechanism of chemical reactions is presented. Following a typical workflow for probing reaction mechanism, the guide introduces a wide range of kinetic and mechanistic tools. In addition to serving as a broad introduction to mechanistic analysis for students and researchers, the guide has also been used by…

Researchers and practitioners alike express concerns about the conceptual difficulties associated with the concepts of momentum and kinetic energy currently taught in school physics. This article presents an in-depth analysis of the treatment given to them in 44 published textbooks written for UK secondary school certificate courses. This is set…

It is difficult to know what to do with meaning. Some kinesiologists, particularly those in the humanities, would argue that it should be given due attention--perhaps even priority attention. Others would argue that meaning is unimportant or simply impossible to study in any objective way. This conundrum can be solved by adopting a new research…

Pulsed ultrasound was used to study tongue movements in the speech of children from 3 to 11 years of age. Speech data attained were characteristic of systems that can be described by second-order differential equations. Relationships observed in these systems may indicate that speech control involves tonic and phasic muscle inputs. (Author/RH)

Describes a simple redox reaction that occurs between potassium permanganate and oxalic acid that can be used to prepare an interesting disappearing ink for demonstrating kinetics for introductory chemistry. Discusses laboratory procedures and factors that influence disappearance times. (CW)

A test for sensitivity to binocular disparity and a shape perception test were administered to four-month-olds. Results indicated that disparity-sensitive infants could perceive three-dimensional-object shape from kinetic and binocular depth information. (PCB)

Simple observation of dance movement, while very useful, can lead to misconceptions, about the physical realities of dance movement, that make learning difficult. This gap between reality and understanding can be reduced by the application of biomechanical techniques such as cinematography, electromyography, and force-plate analysis. Biomechanical…

Conveys an appreciation of enzyme kinetic analysis by using a practical and intuitive approach. Discusses enzyme assays, kinetic models and rate laws, the kinetic constants (V, velocity, and Km, Michaels constant), evaluation of V and Km from experimental data, and enzyme inhibition. (CW)

This study compared the batting swing of two skilled congenitally blind beep baseball players to a perfect kinetic-link model for the batting skill. It found that the subjects used a modified batting technique and that there was an inverse relationship between the subjects' performances and the kinetic-link model. (Author)

This study focused on the cognitive conflicts experienced by young children in using software programs that provided them with tools to create and/or combine individual graphic elements into larger structures. Six 5-year-old children, none with prior computer experience, were observed using three programs--Kids at Work, Picture Perfect, and…

Defines the rate-controlling step in contrast to the terms rate determining and rate limiting. Discusses the usefulness of this concept in describing kinetic isotope effects, consecutive reactions, chain reactions, and enzyme-catalyzed reactions. (CW)

Examines whether kindergarteners, second-graders, fourth-graders, and adults can extract relative weight information from observing collisions and lifting events, and if they can judge whether or not collisions are momentum-conserving. Subjects saw either videotapes of events or sequences of static images; younger children appeared to be…

Describes a kinetic and mechanistic investigation of ascorbic acid by a substitution-inert complex in acidic medium suitable for the undergraduate level. Discusses obtaining the second order rate constant for the rate determining step at a given temperature and comparison with the value predicted on the basis of the Marcus cross-relation. (CW)

Reviews research on student learning about collisions in physics instruction. Focus is placed on the main differences between the spontaneous perspective in describing/interpreting collisions and the disciplinary perspective based upon the energy and linear momentum conservation laws. (PR)