Overview
Heme and chlorophyll (Chl) are essential for life in the biosphere. Chlorophyll catalyzes the conversion of solar energy to chemical energy through photosynthesis. Hemes are involved in electron transport during oxidative phosphorylation and photosynthetic phosphorylation, which generate ATP and NADPH. Indeed, life in the biosphere depends on photosynthesis. Photosynthetic efficiency is controlled by extrinsic factors such as the availability of water, CO2, inorganic nutrients, ambient temperature and the metabolic and developmental state of the plant, as well as by intrinsic factors (Lien and San Pietro, 1975). We believe the time has come to bioengineer chloroplasts capable of synthesizing a short chain carbohydrate at rates that approach the upper theoretical limits of photosynthesis [Rebeiz, C. A. (2010) Investigations of possible relationships between the chlorophyll biosynthetic pathway and the assembly of chlorophyll-protein complexes and photosynthetic efficiency. In: Rebeiz, C. A. Benning, C., Bohnert, H.J., Daniell, H., Hoober J. K., Lichtenthaler, H. K., Portis, A. R., and Tripathy, B. C. eds. The chloroplast: Basics and Applications. Springer. The Netherlands, p 1-24]. This monograph presents an in-depth discussion of the Chl biosynthetic pathway. Its complexity and biochemical heterogeneity and the relationship of this complexity to the structural and biosynthetic complexity of photosynthetic membranes will be emphasized. We will also emphasize in historical perspective, key stages in our understanding of the Chl biosynthetic heterogeneity. A complex biosynthetic process is only fully understood when it becomes possible to reconstitute in vitro every step of the process.Other topics: the development of analytical techniques, cell-free systems, herbicides, insecticides, and cancericides.
