The modulation of ligand p"K"[subscript a] due to its surrounding environment is a crucial feature that controls many biological phenomena. For example, the shift in the p"K"[subscript a] of substrates or catalytic residues at enzyme active sites upon substrate binding often triggers and controls enzymatic reactions. In this work, we developed an…

We propose a series of experiments involving balance readings of an object naturally floating or forced to be partially or fully immersed in water contained in a beaker sitting on an electronic scale balance. Students were asked to predict, observe and explain each case. The teacher facilitated the learning by asking probing questions, giving…

In any demonstration to students, producing light and sound usually ensures interest and can enhance understanding and retention of the concepts involved. A guided inquiry (Predict, Observe, Explain: POE) approach was used to involve the students actively in their learning about the explosive combustion of fine flour particles in air in the…

Students often prefer to study animals rather than plants, because they see plants as passive, less interesting organisms. This paper proposes a simple hands-on laboratory exercise for high-school students (grade 12) to arouse their interest in learning about plants and to demonstrate to them that plants are active organisms capable of defending…

A set-up comprising a magnetic disc, a solenoid and a mechanical balance was used to teach first-year physics students Newton's third law with the help of a free body diagram. The image of a floating magnet immobilized by the solenoid's repulsive force should help dispel a common misconception of students as regards the first law: that stationary…

This study was conducted to examine the results of using a low-cost hands-on setup in combination with accompanying activities to promote understanding of the contact mode of atomic force microscopy (AFM). This contact mode setup enabled learners to study how AFM works by hand scanning using probing cantilevers with different characteristics on…

The dissociation constant, K[subscript d], of the binding of riboflavin-binding protein (RP) with neutral red (NR) can be determined by titrating RP to a fixed concentration of NR. Upon adding RP to the NR solution, the maximum absorption peak of NR shifts to 545 nm from 450 nm for the free NR. The change of the absorption can be used to determine…

To overcome students' inaccurate prior knowledge on primary additive colours, a coloured-light mixer has been constructed to enable students to observe directly the colours produced and reach the conclusion by themselves that the three primary colours of light are red, green, and blue (NOT red, yellow, and blue). Three closely packed tiny…

Liquid 2-chlorobenzaldehyde was converted, by grinding with potassium hydroxide pellets, into equimolar quantities of solid 2-chlorobenzoic acid and solid 2-chlorobenzyl alcohol in a Cannizzaro reaction. TLC, IR, and NMR experiments, using authentic samples for comparison, confirmed the identity and purity of the two products. Guided-inquiry…

Haloperoxidase enzymes are of interest for basic and applied bioscientists because of their increasing importance in pharmaceutical industry and environmental cleanups. In a guided inquiry-based laboratory experiment for life-science, agricultural science, and health science undergraduates, the bromoperoxidase from a red seaweed was used to…

Bacterial conjugation is a genetic transfer that involves cell-to-cell between donor and recipient cells. With the current method used to teach students in genetic courses at the undergraduate level, the transconjugants are identified using bacterial physiology and/or antibiotic resistance. Using physiology, however, is difficult for both…