CELL WALL AND EXTRACELLULAR MATRIX
The extracellular matrix is a network of non living tissues that support the structure of the cell, similar to the cell wall in plants. It is the extracellular matrix that form the framework that ultimately determines the architectural structure of plants and animals (textbook). Due to its dynamic nature, the ECM has multiple functions which include cell adhesion, communication between cell, and Plant and animal cells secrete macromolecules that form the extracellular matrices.
In animals, cells are anchored in an extracellular matrix that is composed of tough fibrous proteins(collagen, laminin, and elastin) which are embedded in a gel like substance of polysaccharides called glycosaminoglycans. The ECM is a weblike structure that surrounds the spaces between the cells and bind cell tissues together. A molecule known as integrins, which is on surface of ...view middle of the document...
For example, the difference in the physical properties of bone, cartilage and tendons, all of which are specialized form of connective tissue.
Cells rely on the ECM for survival, growth, and proliferation. The spreading of the cell on the ECM helps tissues to regenerate after an injury.
In plants, the extracellular matrix form the cell wall. The plant cell wall is one of the most complex forms of extracellular matrices . The cell wall is a tough, rigid, yet fairly flexible layer that surrounds the cells of plants and located just outside of the cell membrane. Plant cell walls are primarily made up of cellulose (polysaccharide). Cellulose is a linear polymer of glucose. The cell wall is made of 3 layers which are middle lamella, primary cell wall and secondary cell wall. The middle lamella is rich is pectins and forms the outermost layer that interfaces between adjacent plant cells and glues them together. The primary cell wall is a thin, flexible layer formed while the cell is growing made of cellulose fibers as well as pectin and several proteins. The secondary cell wall is formed inside the primary cell wall after the cell is fully grown, however it is not present in all plant cells. It is composed of a thick layer of mainly cellulose fibers as well as lignin (which strengthens and waterproofs the wall). The interconnection of the cell walls form the framework to support the entire organism. Therefore, the cell wall does in plants what the extracellular matrix does in animal cells.
The cell wall serves a variety of purposes which include maintaining/determining cell shape, mechanical strength, maintains turgor pressure, acts as a barrier for the plasma membrane, controls the rate and direction of cell growth and regulated cell volume. One of the critical functions of the cell wall is to prevent the cell from swelling due of osmotic pressure.
The properties of the extracellular membrane is essential for growth, wound healing and understanding the concepts behind tumor invasion/methasis in cancer.