Educational Model: Photosynthetic Pigments of Plants

This model is a component of the IUMC (Innovative Educational and Methodological Complex) "Ecology: Constructing the Biosphere", developed in 2008 by D. A. Shabanov, A. G. Kozlenko, and M. A. Kravchenko by order of the NTFP (National Training Foundation) of the Russian Federation (more about this project is in the article "Innovation and Reality"; reasons why this complex is not used are briefly described in the column "Textbooks: Straight into the Day After Tomorrow"). This model is posted here for educational use. The model explains the relationship between plant pigments and the composition of photosynthetically active radiation. The theoretical material related to the model is in the section "Biological Effects of Electromagnetic Radiation" of the manual "Ecology: Biology of Interactions". The model provides an overview of plant pigment diversity and their absorption spectra. The task is to choose an optimal set of photosynthetic pigments for a plant, considering the spectral characteristics of a particular star’s light, and to evaluate photosynthesis efficiency for the selected set. The working area shows a diagram with three arrows. Arrow A shows the star’s spectral composition as a diagram after star type selection (the photosynthetically active part of EMR is used — visible light and adjacent UV and IR zones; this range is also called photosynthetically active radiation, PAR). The triangle at the end of arrow A shows star-light color for human vision. Arrow B shows absorption efficiency across spectral regions for the selected pigment set (relative to full white light). Arrow C shows the spectral composition of light reflected by the plant leaf. The triangle at the end of arrow C shows leaf color for human vision with the selected pigment set. While working with the model, choose one star type (differing in radiation composition) and select an optimal plant-pigment composition.