Aquaporin-1 Essay -- Biology Aquaporin

footingMost modern biology textbooks will tell you that low-molecular-weight molecules like CO2, NH3 (ammonia), and carbamide cross cell membranes by simple diffusion. Some scientists postulate, however, that specific pores midway this transport. A recent study conducted to further this hypothesis examines expression of the piddle channel aquaporin-1 (AQP-1) and its enhancing affect on CO2 permeation into cells.Why would scientists contest the traditional simple diffusion theory? Two strong points of yard led to this experimentFirst, legion(predicate) cell membranes brook a very(prenominal) low permeability to small molecules The outer membranes of some throttletric glands consent to very little CO2 to enter the cell, while most capture egg cells have membranes that act as virtual barriers to the harsh materials demonstrate in their environment. If the simple diffusion theory is correct, diffusion of small molecules into cells should be an unregulated process. If diffusion is an unregulated process, how could some cells have a trim permeability to small molecules than others?Second, scientists have already found membrane proteins that aid the entrance of water and urea While the UT2 protein enables transport of urea ult the cell membrane, an entire class of membrane proteins called the aquaporins enable the permeation of water into cells. If small molecules enter the cell by diffusion, why would the cell have extra mechanisms to facilitate their entry?Any Questions?Q) Whats this diffusion thing you follow talking about?A) Particles randomly flow from areas of high concentration (a jam of particles) to areas of low concentration (not many particles) until they are evenly dispersed.If youve ever puke a normal cell in a c... ...ially exciting fortune to manipulate gas transport rates lies in cancer research, where inhibiting the arrangement of AQP-1 could be the key to killing cancer cells . Cancer cells release more than CO2 than most other cells, so stopping these cells abilty to extrude the gas to their environment would result in cell death. This example is one of many uses for the manipulation of gas transport, however, and the opportunities are endless.The idea that gas transport is actively mediated by the cell is a huge paradigm raise up from the traditional belief that transportation is uncontrolled. Further studies (Cooper and Boron, Am. J. Physiol. In press) have be the conclusion drawn from this experiment, and the search for pores that mediate transport of specific gasses has already begun. The diffusion dogma has been destroyed, and the textbooks will be re-written.