This enzyme degrades cell walls. The procedure and analysis questions found on the student page can stand alone or can be embedded within any context provided by the teacher. The following outline uses the problem of transformation as the context for the activity. Challenge groups of students to develop a method for transforming plant cells without killing the cells. Students develop a general method with justifications for each step.
Students produce protoplasts and answer analysis questions.
Students review their proposed transformation methods, determining which might have worked. Having no cell wall, protoplasts are very sensitive to osmotic differences and must be stored in an isotonic solution to prevent rupture. A hypertonic solution will result in very tiny protoplasts. The sizes of the protoplasts are generally consistent within a particular preparation, but different tissue sources and different osmotic solutions may result in varying sizes of protoplasts. Compare the size of the protoplasts with the size of cells in the untreated leaf squares.