Association for Biology Laboratory Education

Osmolarity and Tonicity: An Inquiry Laboratory Using Plant Material
 

Dee U. Silverthorn

Tested Studies in Laboratory Teaching, 2011, Volume 32

Abstract

The difference between osmolarity and tonicity is a difficult concept for students to understand and often for faculty to teach. We adapted techniques from the traditional potato-plug laboratory to create an inquiry laboratory that demonstrates the principles of osmolarity and tonicity. Students design two experiments: first, they must try to determine the internal osmolarity of their plant material, and second, they test whether a particular solute is a penetrating solute for plant cells. The inquiry level can be adjusted by the instructor.

Keywords:  osmosis, osmolarity, tonicity, solutions, plant cells, sugar transport, urea

Dalhousie University (2010)