Microfibrils terminal complexes

Consolidation of linear terminal complexes. The correlation between linear consolidation of terminal complexes and microfibril width does not appear to be as consistent for linear terminal complexes, although this correlation... 

Thus, linear terminal complex consolidation appears to be a manifestation of the stage of cell wall development rather than a significant factor in the determination of microfibril dimensions. 

Cellulose synthesis takes place in terminal complexes (rosettes) in the plasma membrane. Each cellulose chain begins as a sitosterol dextrin formed inside the cell. It then flips to the outside, where the oligosaccharide portion is transferred to cellulose synthase in the rosette and is then extended. Each rosette produces 36 separate cellulose chains simultaneously and in parallel. The chains crystallize into one of the microfibrils that form the cell wall. 

Fig. 2.—A. A Model Depicting the Molecular Architecture of the Plasma Membrane of Oocystis apiculata During Secondary-wall Formation.74 [MF, Cellulosic microfibrils TC, terminal complexes PTC, paired, terminal complexes CR , regions of possible, transmembrane control GB, granule bands TCI, impressions of terminal, complex particles IP, intramembranous particles, AL, region of membrane phospholipids af-...

I. Tsekos, N. Orologas, and W. Herth, Cellulose microfibril assembly and orientation in some bangiophyte red algae Relationship between synthesizing terminal complexes and microfibril structure, shape, and dimensions, Phycologia, 38 (1999) 217-224. 

Figure 2 Schematic representation of cellulose synthesis from Acetobacter xylinus (not to scale). Microfibrils of cellulose are secreted into the fermentation medium via terminal complex transmembrane synthetic sites. In the extracellular medium, a number of elementary microfibrils coalesce to form a flat, twisting and highly persistent ribbon of cellulose. The presence of polysaccharides in the fermentation medium allows interactions to occur both before and after the assembly of microfibrils into ribbons. The right angle bend at the point of ribbon assembly is purely schematic...

Cellulose microfibril, cellulose-synthesizing terminal complex, dinophyte, heterokon-tophyte, evolution, freeze fracture. 

Tamura H., Mine I., and Okuda K. 1996. Cellulose-synthesizing terminal complexes and microfibril structure in the brown alga Sphacelaria rigidula (Sphacelariales, Phaeophyceae). Phycol Res 44 63-68. 

Tsekos 1. and Reiss H.-D. 1992. Occurrence of the putative microfibril-synthesizing complexes Oinear terminal complexes) in the plasma membrane of the epiphytic marine red alga Erythrocladia... 

Hotchkiss A.T., Jr. and Brown, Jr. R.M. 1987. The association of rosette and globule terminal complexes with cellulose microfibril assembly in Nitella translttcens yar. axillaris (Charophyceae). JPhycol 23 229-237. 

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