3B SCIENTIFIC PHYSICS R05 Handbuch Seite 5

English
Primary cell wall: a gelatinous base substance (matrix) made up of pectin compounds, hemicellulose com-
ponents and proteins. In the matrix, fibril structures can be detected (10-25%) which are arranged in an
irregular, scattered texture (elasticity still present).
Secondary wall: is chiefly composed of 90% cellulose fibrils. The arrangement of the fibrils is primarily in
a parallel texture. There are often deposits of lignin, tanning agents, CaCO
having a marked secondary wall are no longer capable of growth.
Author: Dr. Gerd Vogg, University of Würzburg, Germany
Numbering:
1 Cytoplasm with cytoskeleton
2 Cell membrane
3 a Nucleus
3 b Nucleolus
4 a Smooth Endoplasmic Reticulum (smooth ER)
4 b Rough Endoplasmic Reticulum (rough ER)
5 Ribosomes
6 Plasmodesmata
7 Chloroplasts
8 Mitochondria
9 Dictyosomes/Golgi apparatus
10 Vacuole
11 Microsomes/Microbodies
12 Cell wall (layered structure)
Model of a Plant Cell
(Magnification approx. 500,000-1,000,000)
, SiO or colouring agents. Cells
3 2
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