Fig 3 - uploaded by Ivan Zubov
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(a) Fraction of cell wall of juniper wood (magnification 5000×); (b) boundary between S2 and S1 layers of cell wall (50000×); (c) cross fraction of juniper wood after freezing in liquid nitrogen (200×); (d) helical structure of tracheid cell wall with destroyed S2 layer (2000×); (e) cleavage of cell wall of juniper wood sample tracheids (20000×). Images were recorded on a Sigma VP (Zeiss) SEM equipment. (f) Surface of S1 layer of cell wall of the radial fracture of juniper wood sample after treatment with water (amplitude error); the image was recorded on a Multimod 8 (Bruker) AFM equipment.
Source publication
![Fig. 2. Model of formation of lignin-carbohydrate matrix structures [1].](profile/Ivan-Zubov-2/publication/263064581/figure/fig1/AS:652208894918656@1532510126155/Model-of-formation-of-lignin-carbohydrate-matrix-structures-1_Q320.jpg)
The ultramicroscopic composition and supramolecular structure of wood matrix were investigated by methods of electron and atomic force microscopy (AFM). New data on specific features of the composition and cell wall structure of Juniper wood (Juniperus communis L.) were obtained. Native lignin was found to be water soluble. It was also shown that l...
Contexts in source publication
Context 1
... cellulose binary system stratifies, forming elementary fibrils coated with a layer of hemicelluloses gel. Due to the linear structure of cellulose molecules, the press ence of hydroxyl groups, and the cross linkage of cell lulose macromolecules through hydrogen bonds, elee mentary fibrils form a crystalline structure (light regions in Fig. ...
Context 2
... nanofibrils with the same ratio of components in the system. Strict orientation of hemicellulose moll ecules along the fibrils of cellulose has been noted. In a number of cases, diffusion proceeds so deeply that hemicellulose prevents cellulose molecules from comm ing closer together and amorphous regions appear in its structure (dark regions in Fig. ...
Context 3
... of cell wall layers in juniper wood and orientation of cellulose microfibrils in them can be clearly seen in Fig. 3e. As a result of cell wall rupture, the internal surface of the cell (verrucous layer), as well as layers of secondary cell wall, are seen. For example, the most extensive median layer of the secondary cell wall S2, comprising mainly cellulose (up to 70%), proo vides the necessary rigidity and strength to the cell wall of tracheids and ...
Context 4
... the primary (P) and secondary (S) layers, the cell wall of juniper wood contains a tertiary layer (the verrucous layer) (Fig. 3e). The verrucous layer lines the inner cavities of cells, as well as surfaces of ...
Context 5
... different structure of layers of the cell wall is most probably connected to the different mechanisms of formation and combination of cellulose microfibrils in them. Analysis of Fig. 3e allows the conclusion that the formation of crystals in S1 is possible only upon On the contrary, the growth of microfibrils in S2 occurs longitudinally, not transversely. It may be supp posed that one molecule of an enzyme catalyzing the synthesis of cellulose from glucose provides the elongaa tion of several macromolecules of ...
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Citations
... Also hemicelluloses have limited thermodynamic compatibility with lignin. Extra strength of this composition is given by mechanical bonds between macromolecules of lignin, hemicelluloses and cellulose [1, 2]. The aim of this work is application of physic-chemical model of structure and self-assembly of wood substance for studying of specific features of ultra-micro and submolecular structure of coniferous wood matrix with assistance of modern methodical approaches and by means of analytical instruments. ...
... In most cases this cell wall element goes through pores and ruins together with remains of cytoplasmic membrane during the process of cells' lignification, that's why it can be hardly identified. According to modern concepts the tracheids' cell wall consists of two components: thin primary (Р) and secondary (S) layers, which are different both in composition and in structure [2,6,7]. Secondary layer in its turn consists of three layers S 1 , S 2 and S 3 , gradually deposited during the growth process. ...
The ultra-micro structure and submolecular structure of coniferous wood matrix were investigated by methods of scanning electron (SEM) and atomic-force microscopy (AFM). New improved method of wood investigation by SEM including the step of cryomechanical sample preparation was suggested. New data on specific features of the composition and cell wall structure of Juniper wood (Juniperus communis L) were obtained. Performed investigations experimentally confirm the physic-chemical model of structure and self-assembly of wood substance and prove its application for certain objects.
Main conclusion:
The investigations confirm the physicochemical nature of the structure and self-assembly of wood substance and endorse its application in plant species. The characteristic morphological features, ultra-microstructure, and submolecular structure of coniferous wood matrix using junipers as the representative tree were investigated by scanning electron (SEM) and atomic-force microscopy (AFM). Novel results on the specific composition and cell wall structure features of the common juniper (Juniperus Communis L.) were obtained. These data confirm the possibility of considering the wood substance as a nanobiocomposite. The cellulose nanofibrils (20-50 nm) and globular-shaped lignin-carbohydrate structures (diameter of 5-60 nm) form the base of such a nanobiocomposite.
