We often say food and fuels "contain" energy. It is more accurate to say that energy is stored in the "fuel-oxygen system" generated during photosynthesis. It is definitely "not" stored in fuels or food (except for the very small amount of energy that can be obtained during anaerobic respiration). Aerobic respiration…

Potassium is the main intracellular ion in prokaryotic and eukaryotic cells and is essential for their functions, making potassium one of the most important electrolytes in physiology. In humans, potassium plays a vital role in several physiological functions, including the maintenance of fluid balance, generating the membrane potential of cells,…

Learning and retaining science content may be increased by applying the basic science material to real-world situations. Discussing cases with students during lectures and having them participate in laboratory exercises where they apply the science content to practical situations increases students' interest and enthusiasm. A summer course in…

Electrochemistry is a difficult subject for students at school and beyond and even for their teachers. This article explores the difficult "truth" that, when a current flows from a galvanic cell, positive ions within the cell electrolyte move towards the electrode labelled positive. This seems to contravene the basic rule that like charges repel…

Describes a demonstration for showing the electrical activity in nerve and muscle including action potentials, refractory period of a nerve, and fatigue. Presents instructions for constructing an amplifier, electronic stimulator, and force transducer. (GS)

Presented are the main features of lung histology as a source for biology teachers. Includes background material on the lung as well as labeled photographs and drawings. (BR)

Discusses between-species variation in adaptation of the photosynthetic mechanism to cope with wide fluctuations of environmental water regime. Describes models for water conservation in plants and the role of photorespiration in the evolution of the different pathways. (CW)

Describes 36 science activities. Topics include: osmosis, fermentation, anhydrobiotic organisms, breathing monitors, trypsin, weeds, amyloplasts, electrolysis, polarimeters, ethene ripening of fruit, colorimetry, diffusion, redox reactions, equilibria, acid-base relationships, electricity, power, resonance, measurement, parallax, amplifiers,…

Presents six selected biology notes which could be used in school biology courses. Each includes the name of the author and a description of activities suggested. (HM)

Presents the mathematics of body size and surface area to volume. Examines arguments used related to the topic. Concludes that while some of the traditional arguments are valid, most are not. One analysis for an organism is provided in an appendix. (YP)

Twenty science experiments are presented. Topics include recombinant DNA, physiology, nucleophiles, reactivity series, molar volume of gases, spreadsheets in chemistry, hydrogen bonding, composite materials, radioactive decay, magnetism, speed, charged particles, compression waves, heat transfer, Ursa Major, balloons, current, and expansion of…

Compares differences in function and behavior of two oxygen-binding proteins, myoglobin found in muscle and hemoglobin found in blood. Describes the mechanism of oxygen-binding and allosteric effect in hemoglobin; also describes the effect of pH on the affinity of hemoglobin for oxygen. (CS)

Describes experiments demonstrating that root pressure in plants is probably controlled by a circadian rhythm (biological clock). Root pressure phenomenon plays significant part in water transport in contradiction with prevalent belief. (PS)