85] Biogenesis and modulation of membrane properties in greening Chlamydomonas reinhardi, y-1 cells

Abstract

This chapter describes the experimental conditions for the modulation of membrane composition and function during the greening process and the analyses utilized for their characterization. The light-driven electron transfer coupled to the generation of an energy-rich state or intermediate utilizable for the synthesis of ATP or active ion transport is associated with a membrane system consisting of closed, flattened sacks (thylakoids). These are located within specific organelles (plastids) as superimposed disks fused to form grana in higher plants and several algae. In certain algae, such as Chlorella, Chlamydomonas mutants, or Euglena, under appropriate physiological conditions such as growth in the dark or in media containing high concentration of a utilizable carbon source but poor in nitrogen supply, the photosynthetic membrane system might be diluted through cell division while the plastid as an organelle and the potentiality to reform the membranes are preserved. The process of reformation of the photosynthetic membranes (greening) offers an ideally suitable experimental system for the investigation of the mechanism of biological membrane formation as related to its two major aspects, the structural and functional ones.