Master Hemoglobin with Picmonic for Medicine

Hemoglobin is a metalloprotein in blood that carries oxygen from the alveolus to all tissues in the body. It is composed of four iron heme subunits that can each individually bind oxygen. These four hemes participate in cooperative binding, which means that when one heme subunit binds oxygen, the others are more likely to bind more oxygen. This gives the oxygen saturation curve its characteristic shape. There are many hemoglobin molecules in red blood cells because the body has high oxygen demands. In areas of high oxygen concentration, the propensity to bind oxygen increases. Such areas include the alveolus, where hemoglobin needs to bind oxygen in order to deliver it to cells. In areas with high carbon dioxide levels, the propensity to bind oxygen decreases, allowing hemoglobin to drop oxygen off in high metabolic areas (because CO2 is a byproduct of metabolism). Additionally, high temperatures and low pH levels reduce oxygen binding. There is a derivative of hemoglobin, myoglobin, which is only found in muscle tissue. It only has one subunit rather than four.