Differentiating biochemistry course laboratories based on student experience
Content and emphases in undergraduate biochemistry courses can be readily tailored to accommodate the standards of the department in which they are housed, as well as the backgrounds of the students in the courses. A more challenging issue is how to construct laboratory experiences for a class with both chemistry majors, who usually have little or no experience with biochemical techniques and biology and biochemistry majors who do. This manuscript describes a strategy for differentiating biochemistry labs to meet the needs of students with differing backgrounds. BIOCHEMISTRY AND MOLECULAR BIOLOGY EDUCATION Vol. 39, No. 3, pp. 216–218, 2011.
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Constructing and orchestrating an upper division biochemistry course is a daunting task given the inherent interdisciplinary and complex nature of the field as well as its rapid evolution. Project Kaleidoscope has even conducted a workshop entitled Biochemistry: Biology or Chemistry, which illustrates the diversity of possible teaching and content paradigms for biochemistry courses . However, little attention has been devoted to the types of students in biochemistry classes. Classes offered in a chemistry department are likely taught to students who may dislike biology and not had it since high school. However, knowledge of biochemistry has become essential to their discipline as the American Chemical Society recognizes biochemistry as one of the five subdisciplines of chemistry . Chemistry students might find themselves in biochemistry class with students who have had exposure to biochemistry in lower and upper division courses. These varying backgrounds and interests are clearly present in first year students and can become magnified in upper level courses unless biochemistry content is integrated throughout the chemistry curriculum.
In principle, biochemistry majors taking two biochemistry courses in different departments should benefit by combining a more reductionistic chemical approach emphasizing thermodynamics, kinetics, and reaction mechanisms with a more systems biological approach emphasizing metabolic and signal transduction pathways and their regulation. More uncertain is the approach demanded in a single required biochemistry course, especially those taken by students with large differences in understanding of and interest in biology.
Little thought has been brought to the challenge of how to differentiate the lab for students with different biochemistry backgrounds. DNA and protein electrophoresis, for example, are increasingly done in introductory, intermediate, and advanced biology courses, which are often taken before or concurrently with biochemistry courses. In contrast, chemistry majors in biochemistry classes may never have heard of electrophoresis as a technique. Project labs are commonly used in which techniques new to students are utilized to address project goals and not as the chief focus of a defined laboratory exercise (e.g. see refs.3–5). This approach does not address the fact that the range of experience with biochemistry lab techniques may vary from none to extensive within a class.
I would like to describe an approach I have used over a 3-year period to differentiate a biochemistry course lab in which students in the course are either chemistry majors (the majority) with little or no biology background since high school or biology/biochemistry majors who have already taken biochemistry and/or other upper division biology lab courses that require similar lab skills. These specific circumstances might be unique to us, but the diversity of students' experiences in lab is not. Hence, our experiences may be useful to others.
Three criteria were used to guide the differentiation process. Students with biochemistry lab background were exempted from specific lab experiments whose foci were experimental techniques/concepts that they had encountered previously. They were expected to apply their experiences in a project-based lab that they helped to design. Finally, unexcused students (nominally chemistry majors) would apply techniques and concepts that they had learned throughout the course and, importantly, in other chemistry courses, in a final, project-based lab. All students participated in the two common labs before they moved into differentiated experiences.
Chemistry majors continued their laboratory studies with a series of common, multipart labs designed to introduce standard biochemistry lab techniques (gel filtration and ion exchange chromatography, polyacrylamide gel electrophoresis, fluorescence spectroscopy, transformation of and expression of a human gene in Escherichia coli, and enzyme kinetic analyses). With these tools in place, chemistry majors were then asked to either design a three-lab period (12 hours) final project or select one from a list of suggestions. Students with previous experience in biochemistry conducted a molecular dynamics simulation lab before they embarked on an extended (nine-lab periods totaling 36 hours) final project. This extended research project has the added advantage of providing a research experience for biochemistry students who do not participate in independent undergraduate research.
PROJECT SELECTION AND DESCRIPTIONS
For students with biochemistry lab experience, many different ways to choose projects were attempted. The simplest was to have students develop their own projects or one suggested by me. To better model the interdisciplinary approach that increasingly characterizes modern biochemistry research, students were encouraged to work with other faculty who would serve as “co-mentors.” Descriptions of three different types of “co-projects” were given to the biochemistry students and to all the faculty in the Biology and Chemistry Departments. The co-projects could be:
linked to a co-mentor's courses, which would work well if the students had already taken or were in the course;
linked to a co-mentor's ongoing or new research project, which might offer a hope of training a student for future independent research with the student.
Students wishing to work with a faculty co-mentor obtained a signed research contract from the co-mentor. Co-mentors had to verify that the project was not merely a simple continuation of an independent research project that the student was already pursuing with them. Faculty co-mentors were told of the time constraints for the research projects (36 hours including planning).
Students prepared a more detailed proposal, which evolved over time. They were asked to write an online blog that summarized their progress and time on task, and meet with me throughout the semester. They were allowed to work in pairs outside of normal hours, if they met the safety standards of the department in which they worked. A final group report, consisting of an introductory, materials and methods, data, results, conclusions, and reference sections was required. Grading was based on a rubric judging the quality of the proposal design, data analysis/interpretation, written report, and their relative independence.
In some years, all biochemistry majors worked on the same project. Students would self-organize and divide tasks to maximize the chances of successfully completing the project. This type of project requires greater self-autonomy and communication within the group and the emergence of leaders, which adds a new dimension to the project that reflects real life dynamics of the workplace.
For students without biochemistry lab experience, a variety of approaches for project selection were used. These students were encouraged to undertake projects that required advanced instrumentation use (e.g. NMR), if they had instrument experience from advanced analytical chemistry or undergraduate research.
A FACULTY APPRAISAL
The approach described here extends active and differentiated learning to another level for biochemistry majors with previous lab experience, although retaining the structure necessary to provide the lab skills necessary for independent and meaningful project labs for inexperienced students. Ultimately, what is most important is the process and experience of research, not the outcomes, and that students meet the desired learning goals. Project-based experiments are designed to better meet the more complex learning goals of applying, analyzing, and evaluating (ideas articulated by Bloom et al.  and used in creating high quality science curriculum ) than are labs designed solely to help students learn new techniques. Learning goals for biochemistry and molecular biology programs proposed by the American society for biochemistry and molecular biology (ASBMB) state that students should be able to prepare reagents, design experiments, understand the limitations of experimental approaches, interpret experimental data, design follow-up experiments, work safely and effectively in a laboratory, be aware of the available resources and how to use them, collaborate with other researchers, and use oral, written, and visual presentations to present their work . The structure of the described projects was designed to meet those goals and student surveys indicate that they did. Project labs may or may not introduce students to new techniques, but they certainly require students to revisit and apply important biochemical techniques in ways which would enhance students' use and proficiency with them. Many of the specific lab skills outlined in a curriculum skills matrix assessment developed by Caldwell et al.  and designed to support ASBMB learning goals were employed in the extended lab project in ways which promoted both skill use and proficiency in use. The matrix makes clear that students develop their skills throughout a curriculum, not in one single lab course.
Over the last 3 years, four different biology faculty have co-mentored projects for biology/biochemistry majors with previous lab experience. Conversations among these faculties have increased. Issues encountered in the extended research projects have led to direct research collaborations between faculty in chemistry and biology. “Co-mentored” projects have the potential to increase interdepartmental links and lead to future teaching and research collaborations between the faculties and to enhance the probability of answering a research question, if the project were an extension of an ongoing research project.
The approaches to lab for biochemistry majors described here are not without potential liabilities. Costs can be higher (yet still be manageable) as it is necessary to purchase nonroutine supplies for a variety of projects. As students often propose projects without being aware of cost and resource limitations, it is important to require them to search for the best supplies at the lowest cost. Being a mentor to students in multiple simultaneous project labs, although exciting, is draining as well. In addition, it is difficult to balance the faculty director's desire for maximal student autonomy in project design and implementation with the realization that ongoing feedback and intervention is necessary for most students if they are to move forward in the project, even though the process is weighted more than outcome. The long-term biochemistry projects also carry both greater risk and reward for students than the three-lab period projects for chemistry majors. Most of their lab grade derives from the long-term project, as it represented the bulk of their lab activity. Projects that ran into problems early in the semester deflated student interest and excitement. Many of the projects devolved into method development, which is not necessarily a negative outcome as it is ultimately required of any scientific project.
A STUDENT APPRAISAL
Project labs have been shown to promote the type of process learning which faculty deem valuable. Surveys given to students after the differentiated labs corroborate the value of such project labs. The students generally reported that compared with typical labs done in science courses, the lab project better helped them to develop problem solving skills, determine the next step, identify limitations of methods/design, understand theory/concepts, work independently in the lab, think creatively about the experiment, feel responsible for experiment, understand the importance/design of controls, and be interested in the lab experiment. Reported levels of self-confidence and excitement about the lab seem to correlate with the quality of the lab results.
Working independently for most of the semester in lab groups can be quite challenging for students, even though group work is common at our institutions as our chemistry courses use active learning pedagogies and all chemistry labs have individual or group project lab components. Students did not report a loss of involvement or cohesion from working at different times and places on the same project. However, written and oral comments from biochemistry students in the extended project labs and observation of their laboratory activities showed that they struggled with the autonomy and with division of labor within their group. The latter in and of itself is not unexpected or negative, in that learning how to work effectively in cooperative groups is essential to the practice of modern science. The gains derived from autonomy, will always be tempered in students' minds with outcome success, which probably contributed to lowered reported gains in self-confidence and excitement if the project faltered.
In summary, it is possible to successfully differentiate a biochemistry lab to meet the needs of students with different knowledge-bases, technical skills, and course/lab backgrounds. Differentiation gives students the autonomy necessary to become independent learners and problem solvers, goals that should be at the top of faculty's list of desired outcomes.