BIO 1140 Study Guide - Desmoplakin, Plectin, Basal Lamina
Document Summary
Instead, turgor pressure builds up that is responsible for rigidity of plant tissue. Structure involves 3 classes of molecules: structural fibres cellulose microfibrils, matrix polysaccharides, adhesive molecules pectins. Basic structural polysaccharide is cellulose, a linear polymer of glucose residues. Joined by beta 1-4 linkages, form cellulose microfibrils. These microfibrils are embedded in a matrix consisting of proteins and two other polysaccharids: hemicellulose and pectins. Hemicellulose are highly branched polysaccharides that are hydrogen bonded to cellulose microfibrils. This crosslinks the cellulose microfibrils into a network which gives the cell wall strength. Pectins are branched polysaccharides containing a lot of negatively charged calagturonic acid which makes it trap water molecules to form gels. Cell walls also contain a variety of glycoproteins that are incorporated into the matrix to provide further structural support. Primary cell wall consists of a loose network of cellulose fibrils.
