In the Classroom
CARBOHYDECK: A Card Game To Teach the Stereochemistry of Carbohydrates
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Manuel João Costa Life and Health Sciences Research Institute, School of Health Sciences, University of Minho, 4710-057 Braga, Portugal;
[email protected] Identifying and differentiating monosaccharide isomers is a key to understanding carbohydrate structural and biological diversities. Introductory biochemistry courses should teach students to identify and classify monosaccharides according to their isomeric characteristics (1, 2). The traditional vehicle for instruction is lectures that recall relevant topics from organic chemistry (like the identification of functional groups, or Fischer representations) and introduce students to new structures. Some courses offer complementary laboratory classes on the identification of monosaccharides based on chemical reactivity (3–5). The relative ineffectiveness of lectures in developing students’ understanding and skills relative to active learning methods is well known (6–7) and also documented for biochemistry classes (8–10). Lectures also limit opportunities for the types of student–student and student–instructor interactions known to promote student learning and motivation (11). The author’s previous experiences with this teaching approach in introductory biochemistry for nonmajors showed that lectures have a low effectiveness. This outcome is not hard to understand. Biochemistry and organic chemistry are traditionally difficult courses for nonmajors (4, 11). Understanding monosaccharide isomers poses specific challenges: (i) an understanding of the underlying organic and general chemistry principles; (ii) a need for skills to infer three-dimensional structures from two-dimensional diagrams; (iii) motivating oneself to master topics of a very abstract and symbolic nature (12). A Card Game To Teach Monosaccharide Isomerism Well-designed educational games can stimulate student participation in class and have a positive effect on the development of important collaborative skills. In teaching chemistry, games have been used for reviewing course materials (13–15), learning chemical species (16 –17), and learning names and functions of analytical instruments (18). Games have been found to be effective for addressing students with
Figure 1. The triose cards: examples from the CARBOHYDECK.
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visual learning styles (19), decreasing student and teacher anxiety and apprehensions (18, 20), and augmenting students’ enjoyment (14, 18–21). This paper describes CARBOHYDECK, a card game designed to motivate undergraduate chemistry or biochemistry nonmajors to learn about isomerism of monosaccharides. It is intended to be used in class and does not require prior attendance at lectures on concepts and structures. Participating students are helped to learn about the different types and classifications of monosaccharides as functional isomers or epimers, to understand how monosaccharide diversity derives from the number of carbons and the organic functional groups in a molecule and the chemical and physical distribution of the groups within the molecule. The competitiveness of the game stimulates interest and active involvement in the subject. The CARBOHYDECK of Cards The CARBOHYDECK is constructed from traditional playing cards. Two of the suits (e.g., clubs and hearts, as shown in Figure 1) are used to represent the two main functional groups: aldehyde and ketone. The numbers of the cards indicate the number of carbons in the molecular skeleton. Numbers below 3 are not used (the smallest monosaccharides being three carbons long), and the maximum number depends on the purposes of the instructor. For example, a deck containing trioses to hexoses would include 15 cards for aldoses and 8 for ketoses. In introductory biochemistry the use of at least six carbons is recommended, so species can go up to hexoses. A file for this 23-card deck is available in the Supplemental Materials.W Playing the Game The object of the game is to gather the highest number of pairs of isomers. Students may work individually or in teams. To begin a game, the class sits around a table and the cards are placed face down as the rules are explained: 1. Each team picks up two cards from the table. 2. The teams have a limited amount of time to decide whether the compounds are isomers and, if so, what type of isomerism it is. 3. Each team presents its decision, explaining its reasoning. 4. Other teams may question the explainers, who must defend their views. 5. The instructor plays the referee: if the explanations are correct and complete, the team continues its turn; if not, the team loses its turn. The instructor may use Socratic questioning to push the team members to figure out what they said that was wrong.
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In the Classroom
Student Responses to the Game CARBOHYDECK was tested in an intensive, twomonth introductory biochemistry course at the National University of Timor Lorosae in East Timor. The students were majoring in agricultural sciences, had very weak backgrounds in chemistry, and had clearly struggled to understand structural representations. The card game replaced the traditional lecture. Some students’ unfamiliarity with functional organic groups was overcome by giving each team a list of groups with their corresponding names. The instructor strongly emphasized the importance of using the correct chemical vocabulary to score. The game was extraordinarily successful at capturing the students’ interest, as evidenced by the fact that they were still playing it 40 minutes after the end of the class period. For the first time in the instructor’s teaching experience, all 23 hexose isomers were inspected meticulously by an entire class of students. It was also clear that students’ initial difficulties with the concepts and with the observation of the structures decreased as the game progressed. It is hard to pinpoint the features of the game that led to these outcomes, yet to the instructor it appeared that the students’ competitive instincts motivated them to collect matches of isomers and get their identifications and justifications right, as they could only score if they demonstrated conceptual understanding under questioning. In addition to promoting learning, the exercise led to improved instructional efficiency, as the hour occupied by the game replaced at least two hours of traditional lecturing on isomeric structures of monosaccharides. Other benefits included enabling the instructor to identify students’ misconceptions and the students to get immediate corrective feedback (much of which was provided by classmates), increasing contact among students and between the students and the instructor, and making the class more enjoyable for students and instructor alike. Conclusion CARBOHYDECK successfully engaged and motivated students with initially low levels of interest in the topic and generally weak backgrounds in chemistry. It is easy to prepare, requiring only an old, even incomplete, deck of cards, trivial to administer. The deck presented in this paper can easily be supplemented (for example with α and β forms of
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sugars) or adapted to instruction on other traditionally difficult topics related to carbohydrates (such as identification of Haworth projections or absolute configurations) (22–23) or other (biological) molecules. W
Supplemental Material
A file with 23 card images for the CARBOHYDECK game is available in this issue of JCE Online. Literature Cited 1. Caldwell, Benjamin; Rohlman, Christopher; Benore-Parsons, Marilee. Biochem. Mol. Biol. Educ. 2004, 32, 11–16. 2. Voet, Judith G.; Bell, Ellis; Boyer, Rodney; Boyle, John; O’Leary, Marion; Zimmerman, James K. Biochem. Mol. Biol. Educ. 2003, 31, 161–162. 3. Malherbe, Johannes S.; Meyer, Cornelius J. J. Chem. Educ. 1997, 74, 1304–1305. 4. Malherbe, Johannes S.; Meyer, Cornelius J. J. Chem. Educ. 1999, 76, 56–57. 5. Senkbeil, Edward G. J. Chem. Educ. 1999, 76, 80–81. 6. Knight, Jennifer K.; Wood, William B. Cell. Biol. Educ. 2005, 4, 298–310. 7. Felder, Richard M. J. Chem. Educ. 1996, 73, 832–836. 8. Anderson, William L.; Mitchell, Steven M.; Osgood, Marcy P. Biochem. Mol. Biol. Educ. 2005, 33, 387–393. 9. Green, John. Biochem. Mol. Biol. Educ. 2005, 33, 205–207. 10. Wood, Edward J. Nature Rev. Mol. Cell Biol. 2001, 2, 217– 221. 11. da Costa, Caetano; Torres Bayardo B. Biochem. Mol. Biol. Educ. 2004, 32, 84–90. 12. Gabel, Dorothy. J. Chem. Educ. 1999, 76, 548–554. 13. Myers, Stephanie A. J. Chem. Educ. 2003, 80, 423–424. 14. Campbell, Susan; Muzyka, Jennifer. J. Chem. Educ. 2002, 79, 458. 15. Helser, Terry L. J. Chem. Educ. 2000, 77, 480. 16. Hanson, Robert M. J. Chem. Educ. 2002, 79, 1380. 17. Haworth, Daniel T. J. Chem. Educ. 2001, 78, 466. 18. Greengold, Stacey L. J. Chem. Educ. 2005, 82, 547–548. 19. Welsh, Michael J. J. Chem. Educ. 2003, 80, 426–427. 20. Granath, Philip L.; Russell, Jeanne V. J. Chem. Educ. 1999, 76, 485–486. 21. Russell, Jeanne V. J. Chem. Educ. 1999, 76, 481–484. 22. Siloac, Edward. J. Chem. Educ. 1999, 76, 798–799. 23. Zhang, Qing-zhi; Zhang, Shen-song. J. Chem. Educ. 1999, 76, 799–801.
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