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The Supramolecular Organization of Photosynthetic Membranes of the Thallus Stage of Porphyra leucosticta Thuret. (Bangiales, Rhodophyta) Visualized by Freeze‐Fracture
Author(s) -
Tsekos I.,
Reiss H.D.
Publication year - 1990
Publication title -
botanica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.871
H-Index - 87
eISSN - 1438-8677
pISSN - 0932-8629
DOI - 10.1111/j.1438-8677.1990.tb00156.x
Subject(s) - thallus , thylakoid , membrane , particle (ecology) , chloroplast , ultrastructure , photosynthesis , fracture (geology) , materials science , botany , biophysics , crystallography , chemistry , biology , biochemistry , composite material , ecology , gene
The supramolecular organization of the thylakoid membranes of the thallus stage in the red alga Porphyra leucosticta is studied in replicas of rapidly frozen and fractured cells. Freeze‐fractured thylakoid membranes exhibit only two types of fracture faces (EF and PF), because the lamellae in red algal chloroplasts are not stacked. The PF reveals numerous, tightly packed, but randomly distributed particles (density range from 2970 to 3550 particles/μm 2 ). In contrast, the EF particles appear organized into parallel rows, the spacing of which is about 60–70 nm (about 8–9 particles occur along 100 nm of the line that is formed). Significant numbers of single EF particles are randomly distributed between the EF particle rows. The particles on both fracture faces (PF and EF) fall into two size classes: 10 to 11 nm (major size class) and 14 to 15 nm (minor size class).