BIO 1140 Lecture 9: Lecture 9-10 Extracellular Interactions.doc
7 Mar 2012
School
Department
Course
Professor
Document Summary
Plant cells: cell walls structure involves 3 classes of molecules: The: structural molecules: cellulose microfibrils, matrix: polysaccharides (e. g. hemicellulose, pectins). Pectins can hold water and therefore allow the matrix to stay moist: adhesive molecules: pectins (long complex carbohydrates that attract water and form a thick, sticky, gel like structure). Glues the cell walls of the adjacent well walls together: primary versus secondary cell wall: primary wall has a loose network of cellulose fibrils. Secondary cell wall has very organized cellulose fibrils that are highly organized. It is multi-layered and full of lignin: plasmodesmata: they are the connections between adjacent cells that are tubes of cytoplasm from one sell to the next, allowing small molecules and ions to pass through the channels. They normally have a small piece of smooth er sticking through it, and the function is not known. The adjacent cells are in chemical communication with one another due to these holes.
