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…

The Beer-Lambert law is a fundamental relationship in chemistry that helps connect macroscopic experimental observations (i.e., the amount of light exiting a solution sample) to a symbolic model composed of system-level parameters (e.g., concentration values). Despite the wide use of the Beer-Lambert law in the undergraduate chemistry curriculum…

This paper was inspired by the work of a previous contributor on the subject of modelling plague epidemiology by comparing it to the physics of series radioactive decay, RC transients, and fluid dynamics. An Arduino-based experiment to illustrate the fluid-dynamical case is described. Attention is drawn to important differences between systems…

In this work, we discuss the importance of underlying theoretical assumptions in research, focusing on the conclusions reached when analyzing data from a misconceptions constructivist (stable, unitary) perspective in contrast to a fine-grained constructivist (resources, knowledge-in-pieces) perspective. Both frameworks are rooted in the idea that…

This article is a presentation of a three-day sequence of lessons that engaged fifth-grade students in an exploration following the activities of scientists. From asking questions and analyzing data, to engaging in scientific modeling, to defending their theories to the scientific (classroom) community, these fifth graders were mirroring how…

Explanations of phenomena in chemistry are grounded in discussions of particulate-level behavior, but there are limitations to focusing on single particles, or as an extension, viewing a group of particles as displaying uniform behavior. More sophisticated models of physical processes evoke considerations related to the dynamic nature of bulk…

Nitrogen- or phosphorus-based fertilizers, used in agriculture, can run off into nearby waterways during periods of heavy rain or high flow and cause harmful blooms (Paerl et al. 2016), low oxygen (Joyce 2000), and decreased biodiversity (Sebens 1994). Studies of the effects wetlands can have on water and habitat quality (Verhoeven and Meuleman…

The paper discusses some interesting, mainly philosophical paradigms of the modeling and control areas, which are still partly unsolved and/or only partially studied. First the possible introduction of a prejudice free control--similar to the term for the modeling introduced by Rudi Kalman--is investigated. Next the real constraints in real…

This paper reports a case study of four grade 10 physical sciences teachers' PCK about graphs of motion. We used three data collection strategies, namely teachers' written accounts, captured by the content representation (CoRe) tool, interviews and classroom observations. We conceptualised the PCK displayed in the CoRe tool and the interviews as…

Understanding the relationship between energy and temperature can be challenging, but it is crucial to developing an understanding of the underlying mechanism behind climate change. In this article, the authors review the development of a unit that focuses on the relationship between energy, greenhouse gases, aerosols (a suspension of fine solid…

We introduce a novel approach to visualizing temporal clickstream behaviour in the context of a degree-satisfying online course, "Habitable Worlds," offered through Arizona State University. The current practice for visualizing behaviour within a digital learning environment is to generate plots based on hand-engineered or coded features…

A learning path has been developed on system dynamical graphical modelling, integrated into the Dutch lower secondary physics curriculum. As part of the developmental research for this learning path, students' understanding of the relation structures shown in the diagrams of graphical system dynamics based models has been investigated. One of our…

In learning conceptual knowledge in physics, a common problem is the incompleteness of a learning process, where students' personal, often undifferentiated concepts take on more scientific and differentiated form. With regard to such concept learning and differentiation, this study proposes a systemic view in which concepts are considered as…

This article describes a two-day optics laboratory activity that investigates the scientific phenomenon of reflection, which students are generally familiar with but usually have not studied in depth. This investigation can be used on its own or as part of a larger unit on optics. This lesson encourages students to think critically and…

Previously, we analyzed the Force and Motion Conceptual Evaluation in terms of a resources-based model that allows for clustering of questions so as to provide useful information on how students correctly or incorrectly reason about physics. In this paper, we apply model analysis to show that the associated model plots provide more information…