A Problems-Oriented Biochemistry Laboratory Program Joseph H. Dreisbach University of Scranton. Scranton. PA 18510
During the past decade the biochemistry major has hecome a popular alternative to the traditional one in chemistry. During 1985the American Chemical Society Committee on Professional Training (ACS-CPT) invited comments on a proposal to include biochemistry in the core curriculum of ( I ) . A oroanoroved undereradnate chemistrv - oroerams . posed ~ ~ ~ - a ~ chemistry ~ r & e program d with hi'ochem&ry emohasis. vrenared hv ACS-CPT in coooeration with the ~ n ; e r i c a n ~ o c i e o1'~iological ry Chemisls. ;,as also preiented in 1985 (2). The importanre of hiochc.mistry as a core course and as a program concentration is recognized among educators. Currioulum Perspective The Universitv of Scranton is a vrivate. indeoendent lihera1 arts institution enrolling approximatd~y4,5'00students. Underaraduate chemistrv . .roer rams have four areas of concentration: chemistry, biochemistry, chemistry-business, and medical technology. The chemistry and hiochemistry curriculum both exceed the ACS-CPT guidelines for certification. This curriculum is typical of that encountered hy most other ACS-approved chemistry programs in smaller undergraduate oriented departments. Biochemistry majors and some chemistry majors enroll in the biochemistry lecture and lahoratory during their senior vear with . ~hvsical " chemistrv as a co-reouisite. Thev have already had courses in advanced organic and instrumental analysis along with those respective laboratories. In addition, the seniors are in the midst of their undergraduate research topics having already taken the literature and seminar courses in their junior years and formally enrolled in the research course their senior year. The situation, then, is one where the students are familiar with the theory and use of most of the instruments available in our department, are able to utilize the literature, and have completed a t least two advanced lahoratory courses. My experience has shown that most students found many
of the experiments and some of the tasks in the hiochemistry lahoratory routine and to he the same as those performed in previous lahoratory courses. These students became bored quickly, especially with the experiments that emphasized techniques. In response to this situation, I developed a new biochemistry laboratory course. This program is capahle of provoking scientific curiosity, creativity, and independence and exposes students to a varietv of techniques. The orogram itlio retains a struct?lred fnrmat since our fariliticsand stafiing could not pro\.idc an "open" lahnratory. Objectives of the Program The lahoratory objectives can he placed into pedagogical and administrative categories. Certainly introduction to selected biochemical techniques and observation of hiochemical phenomena are major objectives. This program also emphasizes utilization of the literature, formulation of exoerimental protocols, data analysis, and interpretation-and detailed report writing. Cost effectiveness and supervision requirements are major administrative concerns. Exercises and projects must lie within the instrumental capabilities of the department. Considerable attention is also directed to lahoratory safety whenever experiments are designed or modified. Structure of the Course This biochemistry lahoratory program is a 3-credit, 6-hour course. It is divided into two distinct portions to meet the objectives (Table 1).In the first portion, referred to as the
Table 1. Objectives of the Problems-Oriented Biochemistry Laboratory Structured Sequence Orientation with labamtory facilities and instruments lntrcduction to analytical and preparative biochemical techniques Problems-OrientedSequence Independent study literature to prepare experimental protocols Experiments directed toward problem solving Detailed written reports Use of
Presented at the 189th National Meeting of the American Chemical Society. Miami. FL. 1985.
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Journal of Chemical Education
structured sequence and utilizing the first 5 weeks of the semester, students perform a series of exercises that involve some common biochemical techniques. Methods and protocols are provided to the students. This portion of the course allows the students to become acquainted with the laboratory facilities and instrumentation. I t also allows the instructor to establish rules for keeping the notebook and report writing. A number of hiochemistry lahoratory texts can be used for this part of the course (3-6). The second part of the course.. the . oroblems-oriented nortion, provides the student with a more independent learkng experience. Here the students are presented with a biochemical problem or topic and are asked to examine some portion of that problem. They are provided with a few pertinent literature references and are required to submit a protocol that, when successfully completed, will provide sound experimental data answering the question proposed. Following approval or revision of the protocol, students perform the experiments and submit a clear, concise report describing the results and providing a discussion. This is not a research course since the objectives are too specific and class time too short to allow digression into other areas of interest. I t is the combination of the shortstructured sequence used for laboratory orientation and introduction to common techniques followed by the prohlemsoriented sequence of exercises that results in a structured laboratory course that also provides for independent learning and scientific inquiry.
Table 2.
Examples of Some Laboratory Exercises Structured Sequence
Quantitative analysis of amino acids end proteins ( 5 ) isoiation and purification of wheat germ acid phosphatase (5) DNA isolation.. ourificatian.. and soectral anaivsis 13 , Qualitative and quantitative analysis of carbohydrates ( 5 ) Properties of bile sales (7)
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~ . ~ ~ , ,
ProblemSOriented Topics Kinetics and inhibition of wheat germ acid phosphatase ( 5 ) Studies of mvaolabin denaturation 1.9-10 hydrolys~sD ~ O ~01Upen C IaS l l n ( 1 I) Prollne ~ p t a k eby a co agenolyt c bacterrum ( I 2 1 3 ) Cornpar son of acllrat on energ es tar enzyme and acnd-catalyzed hyarolys s reactions ( 14) Analysis of chlorophyiis (15)
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151 Stenesh, J."Experimental Biochemistry"; Aliyn and Bamn: Baston, ,984. 161 Stronx, F. M.: Koch, G . H. '"Biochemistry Laboratory M a n u s c Wm. C. Brow: h h t > n s e 1A 14R1 ~.., (71 Fung,B. M.; Williams, W.;Smith, R. L. J. C h m Educ. 1978,55.198. (81 Herskovits. T. T.;Jolliet, H. Science 1969,163,282, 191 Scheeter,A.;Epetein.C. J. J. Mol. Bioi. 1968,35,567. 1101 Corbett, R. J.:Roche. R.S. Biochemistry I984,%?,1888. Ill1 McCarrick, T. A,; McLalferty, F. W. J. Chem Edur. 1984.54.463, . C.: Magasink. B. J. Bocteriol. 1979,140, 498. (121 Biandrirr, M 1181 BWovsl, P.: Moreira, E.;Desmazeaud, D. J. Aaclariol. 1983,155,1123. 1141 Adams. K. R.: Meyer8.M B.J Chrm. Educ. 1985.62.86. 115) Silueira.A..Jr.: Koehler, J, A,; Beadel, E.F.. Jr.; Monroe,P.A.J Chem.Edue. 1984, 61. 264. ~~
Examples of Some Laboratory Exercises Table 2 provides a list of some exercises used in this program. The experiments in the structured part of the course are found in a number of lahoratory texts. A series of experiments introducing students to proteins, nucleic acids, lipids, and polysaccharides is one way of structuring the first 5-week sequence. ~~~~~~~~~oriented exercises can be obtained from numerous sources including this Journal and one's own research interests. It is important to note that in these exercises students should not merely repeat experiments described in the literature. One objective is to have each student extract as much information as required to perform the investigation properly. Protocols that are not structured to solve the problem with an economy of time and material should be evaluated accordingly. Concluslon As mentioned above, our facilities are limited, and an "open" laboratory is not feasible. This program limits the time students are in the hiochemistry lahoratory allowing continuous suoervision hv one instructor. Timetables are critical, and students areeautioned to submit original and revised protocols promptlv. . . Protocol review and revision is a mnjtw time-demanding iactor on [he instrucror. This prohlrmn-orirntrd biorhrmistr~lahoratvry. .program . is a cost-effective course requiring limited supervisory personnel. I t is sufficiently flexible to meet the instrumentation caoahilitv and budeet restrictions of anv" deoartment. Most . importantly, i t provides students with an independent and challenging program allowing for creativity and ingenuity.
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Acknowledgment 'l'hr nuthc~ris grateful to the Camille and Henry 1)reyfuss Foundation. whwh rm~vidrdan E:riurntion Innowtion Grant to support this projkct. Literature Cited 111 ACSComm. Pro. Tmin.N~m1.1985 (11.5. 121 ACSCmmm. Pro. Train. Ncurd 1985 121.4. 131 Clark, J. M.. Jr.: Svitzor, R. L. "Exporim~ntalBiochemistry"; W. H. Freeman: San hancircn. 1977. (41 Crandall. C..D. "Selected Exercises for the Biochemistry Laboratory; oxford Uni. vorsity Press: N e w York, 1981.
Volume 63 Number 12 December 1966
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