Photosynthesis is a vital component of any undergraduate biology course. Despite its central importance in providing biochemical energy, fixed carbon and oxygen for all life on Earth, it remains an area which students find uninteresting and difficult to comprehend.

A set of interactive, multimedia modules have been combined on a CD-ROM, which provides a new approach to university teaching of photosynthesis. Features include animations of the photosynthetic electron transport process, serving both as an introduction to experimental exercises and as stand-alone material for use in undergraduate lectures or tutorials, and simulated experimental models of photosynthetic gas exchange and chlorophyll fluorescence which can be used either as stand-alone packages or, where equipment is available, to supplement and enrich a laboratory demonstration/experiment.

These provide students with access to the latest experimental techniques and theory, providing an experience and knowledge base that facilitates understanding of the subject in greater depth.

The challenges of photosynthesis education

Photosynthesis raises a number of challenges for teachers. Plant science is, in general, under-represented in high school and undergraduate courses (Hershey, 1992), and often receives a poor response, especially from students enrolled in biomedical type courses (who cry "plants are boring"). Aware of the central role of this process in biology, teachers struggle, nevertheless, to promote the relevance and importance of photosynthesis to their students.

Photosynthesis is also a conceptually difficult topic, which spans several disciplines (biophysics, biochemistry, ecophysiology) and organisational levels (molecules, cells, organisms, ecosystems). Because of these problems of relevance and difficulty, major misconceptions often persist in students' understanding of photosynthesis.

There is clearly a need for new teaching materials and approaches that present photosynthesis in all its complexity, but in a way that stimulates the interest and excitement of students, and promotes deep and accurate understanding. Multimedia has the potential, in combining written and spoken word with dynamic pictures and models, to bring abstract concepts and invisible objects and processes to life, and to do so in a flexible and reliable way which increases retention and learning.

Main menu of Photosynthesis in Silico

Content of the CD-ROM

The CD-ROM is designed as a series of five modules (Table 1). Modules 1 and 5 contain 4 experimental senarios, in which students conduct simulated experimental procedures, and collect and analyze data. These require virtually the same level of involvement and understanding from students as the experiments they simulate, while ensuring that a consistent practical outcome is achievable by all students, even in large classes, and that theoretical aspects are not obscured because of technical problems. Modules 2 - 4 (Table 1) cover theory in areas at the forefront of research that are not well described in the available texts, are conceptually difficulty for students and/or are better illustrated through animation. Animations and dynamic links between text and figures make the modules attractive and visually stimulating, and also clarify and reinforce concepts. All modules include an extensive, up-to-date list of references. The modules are all interactive, providing flexibility to students in the pace, depth, and sequence in which they complete material in the modules, in or out of class time.

Table 1. The five modules of the Photosynthesis in silico CD-ROM, showing topics and target audience. The target audiences are given as years where these modules are currently in use at the University of Wollongong.

Module #		Topic		Target audience*
1		Oxygen evolution by Egeria (2 modules) a) Effect of light quality on photosynthesis		1st Year
		b) Effect of light quantity on photosynthesis in sun and shade leaves		2nd Year
2		Plant adaptations to Sun and shade		2nd Year
3		The photosynthetic electron transport chain		2nd Year
4		How do plants cope with excess light?		3rd Year
5		Measuring photosynthesis using chlorophyll fluorescence		3rd Year