Though strictly speaking, an antibody is not the same as an immunoglobulin; B cells can produce two types of immunoglobulins-surface immunoglobulins, which are B cell receptors; and secreted immunoglobulins, which are antibodies. So antibodies are one of two classes of immunoglobulins.ach antibody binds to a specific antigen; an interaction similar to a lock and key. An antibody (Ab), also known as an immunoglobulin (Ig), is a large, Y-shape protein produced by plasma cells that is used by the immune system to identify and neutralize pathogens such as bacteria and viruses.
About 95 percent of the dry weight of the red blood cell consists of hemoglobin, the substance necessary for oxygen transport. Hemoglobin is a protein; a molecule contains four polypeptide chains (a tetramer), each chain consisting of more than 140 amino acids.
Gas Transport by the Blood. Almost all the oxygen (over 98%) is carried in the blood by attachment to hemoglobin, a protein in the red blood cells. As oxygen is dissolved in the blood, it rapidly combines with the hemoglobin to form oxyhemoglobin. Each hemoglobin molecule can bind up to four oxygen molecules.