Tackling challenging concepts with problem-based learning in the classroom

Our guest blogger is Elizabeth Burton, an adjunct professor in the Department of Biology. Elizabeth was a participant in the 2013 Summer FTI.  This post is a report on her experience using problem-based learning in her courses.

In the classroom, many students have trouble translating the facts into action.  This is particularly true in the non-majors introductory biology classes that I teach.  Many of these students enter into the classroom with little knowledge or understanding of biology, with many having no interest at all in the subject.  Most only take this class as a general education requirement.  I have chosen to incorporate problem-based learning into the classroom to provide students with a way to translate abstract ideas into functional scenarios.  This is of particular importance in biology because many of these biological concepts translate into proper functioning of the human body.  From my experience, both personally and as an instructor, I have found that it is easier to understand a tough concept when you are “forced” to work through it.  Students are more interested in the topic when you relate it to something familiar to them or something that is more interesting than a cell, such as a disease.

One example of problem-based learning from my classroom is based around the concept of mitochondrial functioning in cellular respiration.  This concept is probably one of the most difficult for students to understand because everything is explained at a minute level.  In this section, I give a lecture on the basics of the electron transport chain in the mitochondria in one class period.  During the next class period, I reinforce this material through the use of a case study.  The one that I use is from the National Center for Case Study Teaching in Science (http://sciencecases.lib.buffalo.edu/cs/), which is a great resource for case studies in all sciences, not just biology.  In this case study we follow the story of Connor, who is a wrestler hoping to lose weight and get down to a lower weight class for competition.  His friend suggests taking a weight loss drug that is available from foreign internet pharmacies but is banned in the United States.  Through this case study, the students dissect the mechanism behind how this weight loss drug works, looking specifically at mitochondrial functioning and why this drug is banned in the US.  Once the students figure out the mechanism by analyzing actual scientific data, I then show them additional substances that have a negative impact on mitochondrial functioning such as cyanide.

From my experience, more students understand the basic concepts after working through a case study problem.  In the classroom, I usually use one case study per unit to reinforce the material from lecture and multiple questions during the lecture.  I have had positive feedback from students on the use of problem-based learning in helping them understand the material.  The in-lecture questions also allow the students to think about the material that we have not yet covered to see if they can find the answers.  Sometimes I ask the question after covering a topic to reinforce understanding.  Frequently, students retain lecture material if they were “forced” to think about it during class instead of frantically writing notes.  While this does take away from the amount of material that I am able to cover, the material that we are able to cover during the semester is understood and retained better by most students.  Overall, I have found problem-based learning to be a welcome addition to the classroom that has facilitated a greater understanding of complex biological ideas.