Alternative assessment method in biochemistry education: Graphical representation of oxygen binding and delivery

Conceptual understanding is one of the essential levels of understanding in biochemistry. Some topics in biochemistry also require students to use complex graphical representations and mathematical knowledge to understand concepts and explain physiological phenomena. This project focuses on how to measure students’ conceptual understanding in the context of undergraduate biochemistry course at DePaul University.

The topic of oxygen binding to hemoglobin in the blood and its delivery from the lung to tissues is being assessed not only by asking direct information, which may eventually be answered by recalling and recognizing (i.e. rote learning), but also by asking students’ reasoning behind their answers. This topic is difficult for students to learn. Students are expected to interpret how oxygen pressure determines the oxygen saturation level in hemoglobin; how to map out the saturation level at a given pressure thus the amount of oxygen delivered; how tissue acidity correlates with the level of carbon dioxide, and how changes in both as well as another modulator molecule affect the release of oxygen from hemoglobin to tissue thus its delivery from the lung to tissues and the adaptation of a person to high altitude.