Aligning biochemistry to the interests of biology students using haloperoxidase to illustrate reactions of environmental and biomedical importance*

Abstract

Undergraduate degree programs in the biosciences almost always include elements of biochemistry. In the United Kingdom, biosciences programs often have optional pathways to accommodate students of diverse interests. These programs rarely require students to demonstrate any school-level chemistry knowledge, and many students find biochemistry difficult and irrelevant to their primary areas of interest. We have developed laboratory practical work that is used with more than 200 first year (Level 1) students, over 100 second year (Level 2) students, and about 30 final year (Level 3, Honors) students on pathways within a biosciences scheme ranging from Human Biosciences through Plant Sciences and Marine Biology to Environmental Biology. The practical work is based on haloperoxidase enzymes and is modified easily for different student groups and levels. The wide biological distribution of these enzymes and their important biological roles allow students with a wide spectrum of interests to engage with the practical work, and through it with biochemistry. Attempts to align the laboratory work with other aspects of the curriculum were confounded by organizational aspects of the student experience on a complex modular degree scheme.

Using a context-based approach to undergraduate chemistry teaching – a case study for introductory physical chemistry

“…organic (Bennett and Cornely, 2001), inorganic (Breslin and Sanuodo-Wilhelmy, 2001) and physical (Holman and Pilling, 2004) chemistry, and subjects allied to chemistry such as biochemistry (Cornely, 1998) and environmental science (Breslin and Sanuodo-Wilhelmy, 2001;Cheng, 1995) have also been described. Problem-based approaches in laboratory work are also gaining in popularity (McGarvey, 2004;Jervis et al, 2005;Tsaparlis and Gorezi, 2005).…”

Bromo-oxidation reaction in enzyme-entrapped alginate hollow microfibers

“…29 As with all haloperoxidases, VBPO catalyzes the addition of bromine or iodine into organic substrates, producing a range of organic halogenated products. 28,32 These biohalogenation reactions use hydrogen peroxide ͑H 2 O 2 ͒ produced within the cell, to oxidize bromide anions ͑Br − ͒ to form highly reactive hypohalous acid intermediates such as hypobromous acid ͑HOBr͒ or bromonium cations ͑Br + ͒. 32 These species can become substrates for a number of reactions, including halogenation of nucleophilic organic compounds or react with excess H 2 O 2 to yield singlet oxygen in the absence of suitable substrates.…”

“…28,32 These biohalogenation reactions use hydrogen peroxide ͑H 2 O 2 ͒ produced within the cell, to oxidize bromide anions ͑Br − ͒ to form highly reactive hypohalous acid intermediates such as hypobromous acid ͑HOBr͒ or bromonium cations ͑Br + ͒. 32 These species can become substrates for a number of reactions, including halogenation of nucleophilic organic compounds or react with excess H 2 O 2 to yield singlet oxygen in the absence of suitable substrates. 33 Figure 5 shows the reaction scheme for the bromo-oxidation of Phenol Red ͑yellow in color͒ to the brominated derivative, Bromophenol Blue ͑blue in color͒ under physiological conditions ͑pH 6.5͒; this is the model reaction which has been employed to demonstrate bioreactivity in our alginate hollow fibers loaded with VBPO.…”

Red seaweed enzyme‐catalyzed bromination of bromophenol red: An inquiry‐based kinetics laboratory experiment for undergraduates

“…We fully acknowledge the work carried out by the Jervises et al, published in this journal, which has an extensive and broadbrush description of multicourse experiments involving several aspects of haloperoxidase catalysis, especially, by the C. corallina red algal enzyme [18]. Our work, albeit less comprehensive, includes detailed biochemical (a new starting substrate Br 2 PR) and elaborate pedagogical aspects (engagement step, guided inquiry-based collaborative learning, attitude test) to concretely augment the laboratory teaching/learning based on seaweed bromoperoxidases.…”