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Updated: Aug 9, 2026

Studying the Supramolecular Organization of Photosynthetic Membranes within Freeze-fractured Leaf Tissues by Cryo-scanning Electron Microscopy
Published on: June 23, 2016
Structure of a bacterial photosynthetic membrane
1Cell and Developmental Biology, Harvard University, Cambridge, Massachusetts 02138.
Abstract:
The internal photosynthetic membranes of a photosynthetic bacterium, Rhodopseudomonas viridis, have been studied with a variety of electron microscope techniques. The membranes are composed of a sheet of apparently identical subunits arranged in a hexagonal fashion. The individual subunits repeat at a distance of 110 A. Optical transforms have been used to enhance micrographs of this ordered membrane, and the images synthesized in this way show details of each subunit. The individual subunits are asymmetric, differing slightly in appearance at the outer and inner surfaces of the membrane, and these surface patterns seem to be combined in the image of the thylakoid membrane in negative stain. These studies fix a maximum size for the photosynthetic unit of R. viridis and suggest the suitability of this membrane for further diffraction analysis.
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