Aquaporin-1 Essay -- Biology Aquaporin

BackgroundMost modern biology textbooks will severalise you that low-molecular-weight molecules like CO2, NH3 (ammonia), and urea cross cell membranes by simple public exposure. both(prenominal) scientists postulate, however, that specific pores mediate this tape ecstasy. A recent study conducted to further this surmise examines expression of the water channel aquaporin-1 (AQP-1) and its enhancing affect on CO2 pervasion into cells.Why would scientists challenge the traditional simple dissemination theory? twain strong points of evidence led to this experimentFirst, many cell membranes allow a very low permeability to small molecules The outer membranes of some(a) go down ontric glands allow very little CO2 to enter the cell, plot of ground most frog egg cells deliver membranes that act as realistic barriers to the harsh materials present in their environment. If the simple diffusion theory is correct, diffusion of small molecules into cells should be an unregulated proc ess. If diffusion is an unregulated process, how could some cells have a lower permeability to small molecules than others?Second, scientists have already institute membrane proteins that facilitate the entrance of water and urea While the UT2 protein enables transport of urea past 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, wherefore would the cell have extra mechanisms to facilitate their entry?Any Questions?Q) Whats this diffusion thing you keep talking about?A) Particles randomly flow from areas of superior concentration (a lot of particles) to areas of low concentration (not many particles) until they are evenly dispersed.If youve ever put a normal cell in a c... ...ially exciting opportunity to manipulate gas transport rates lies in cancer research, where inhibiting the transcription of AQP-1 could be the key to killing cancer cells . cancer cells r elease more CO2 than most other cells, so tenia these cells abilty to extrude the gas to their environment would result in cell death. This role model 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 grand paradigm shift from the traditional belief that transportation is uncontrolled. Further studies (Cooper and Boron, Am. J. Physiol. In press) have proven 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.