BIO 110 Lecture Notes - Lecture 9: Cooperative Binding, Porphyrin, N-Terminus
Document Summary
Flat, hydrophilic (threonine-rich) face of molecule absorbs to surface of ice crystal. Hydrophobic face repels liquid water molecules, inhibiting further crystal growth. If expose hydrophobic regions stick together. Large, extracellular glycoproteins with molecular weights ranging from 0. 5 to 20. Both membrane bound mucins, and secreted mucins share many common features. They are both highly glycosylated consisting of 80% carbohydrates (primarily n-acetylgalactosamine) Life requires oxygen - which is a problem for us large multicellular organisms, because o2 and co2 are not very soluble water. Myoglobin - monomer; emergency backup for hemoglobin. Iron (fe2+) is at the center the heme prosthetic group. Iron is bound by nitrogen (x4) to the larger porphyrin ring. When o2 is bound, additional hydrogen bonds are formed with upper histidine. When oxygen is bound, the shape of the entire peptide changes slightly - beginning with the movement of the iron - it becomes on the same plane as the ring holding it.
