Definition of Koch's Postulate - Essay Example

Indicating that disease is caused due to the attack by tiny micro-organisms. This formed the basis for further research. Whereas, Robert Koch 1890, a physician and bacteriologist further, confirmed this microbial association with the disease. Based on his constant research he established that: a. The bacteria must be present in every disease. b. The bacteria must be isolated from the host suffering from the disease and should be grown in pure culture. c. The disease must be repeated and reproduced if an organism from the pure culture is inoculated into a healthy host. d. Again the same bacteria should be revered from the infected host.

Bassi and Pasteur did not lay all these systematic postulations. Although these postulates do not work when there is no animal model available to test a specific bacteria. Moreover, a few bacteria cannot be grown in pure culture in laboratory conditions, e.g. Mycobacterium large the causal organism of leprosy cannot be grown in pure culture. In certain cases virulence or disease-causing ability is acquired, so the postulate does not hold true. In certain c the microbe gains access via trauma, injury, or through surgery, then also Koch's postulates are not valid. Moreover, in immunocompromised patients, the postulates can, not be true and if the immunity of an individual is excellent the individual may not reproduce the disease (Definition of Koch's postulates).

Phospholipids have a hydrophilic (water-loving) head and a hydrophobic (water-hating) tail. In the plasma membrane, the father of the phospholipids is arranged as a bi-layer, the hydrophobic tails face each other while the hydrophilic heads are on opposite sides.

Headthe of one osidese layer of phospholipids faces the exterior while the other head faces the interior of the cell. Various protein molecules are arranged in this phospholipids bilayer. The association of the phospholipids with the protein molecule helps these protein molecules to act as transporters of all the major mules which are secreted by the cell and which are taken in by the cell. Such proteins are called transmembrane proteins, e.g. proton pump, G- protein-coupled receptors, etc.

Some of the proteins are lipid-anchored proteins e.g. G- protein. Some are peripheral proteins, e.g. enzymes and hormones. These proteins are vital for the survival of cells and hence the Hellenism may be a single-cell organism or a multi-cellular organism. They aid in transporting chemicals and information to and fro in the cellular atmosphere. Thus phospholipids play a vital role in cellular morphology and physiology, without these anchoring molecules proteins cannot function properly. They play an imperative role in cellular communication (Phospholipids)