BIO271H1 Lecture Notes - Lecture 8: Fetal Hemoglobin, Red Blood Cell, Carbonic Anhydrase
Document Summary
Hemoglobins: found mainly in vertebrates, composed of a globin protein and a heme molecule which has a porphyrin ring structure complexed to an iron. Is a reversible reaction: hemoglobin does not change its substrate, generally found within blood cells, appears red when oxygenated, myoglobin is a type of hemoglobin found in muscles. Hemoglobin means one heme and one globin. Myoglobin facilitates the movement of oxygen into the tissues. Oxygen storage molecule: each of the hemoglobin molecules can bind one oxygen molecule, so a hemoglobin tetramer can bind four. Hemocyanins: arthropods, molluscs, copper is directly complexed to the protein (while iron is attached to the porphyrin ring which is attached to the heme, usually dissolved in the blood/hemolymph, appears blue when oxygenated. Hemerythrins: sipunculids, priapulids, brachiopods, some annelids. No evolutionary similarity: iron is directly bound to the protein, found inside coelomic cells, appears violet-pink when oxygenated. Oxygen is going to diffuse down its pp gradient.
