|MadSci Network: Genetics|
I'll give you just a bit of info on hemoglobin and sickle cell anemia and then send you net-surfing as I found a few good sites (with better pictures than what I could give you! :) Most of my info is coming from Stryer's "Biochemistry" textbook: Hemoglobin (the structure of which can be found here) is composed of four separate peptides: two "alpha" and two "beta" chains. Each peptide binds a heme molecule, which in turn positions the oxygen that hemoglobin delivers to the tissues. In a normal person, the red blood cell contains a very high concentration of hemoglobin, but the individual hemoglobin molecules do not interact. In sickle cell anemia, a single amino acid mutation (from glutamate to valine) in the beta chain causes one hemoglobin to "stick" to another hemoglobin in low-oxygen conditions, eventually forming long fibers of hemoglobin. These fibers cause the red blood cell to sickle. More info on sickle-cell disease, including why it can be beneficial in some areas of the world can be found here. Thanks for you question. Michael Crawford email@example.com
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