The hemoglobin holoenzyme (active enzyme) is a complex of an iron ion and 4 subunits- 2 hemoglobin alpha and two hemoglobin beta. People with sickle cell disease have mutated beta hemoglobins. The mutation is a single nucleotide exchange, that changes the 6th amino acid of protein primary struture - a Glutamic acid into Valine. This one alteration changes the tree dimentional structure of hemoglobin beta so, that it forms lond fibres that disrupt the normal circular form of the red blood cells.
Schizocoely is a process by which some animal embryos develop while splitting the mesodermal embryonic tissue. On the other hand, <span> enterocoelous was formed </span><span>in which the coelom forms from pouches "pinched" off of the digestive tract.</span>
The immune system is the bodies defense against invaders and is located in all body tissues with concentration in the mucosal surfaces and skin.