Answer
B. Hemoglobin
Work Step by Step
Hemoglobin is a pigment present in red blood cells (ethrocytes) with a high attraction for oxygen. The “globin” part of hemoglobin is a protein containing four polypeptide chains. The “heme” portion of hemoglobin is an iron-containing group that is present at the center of each of the four polypeptide chains. This iron combines reversibly with oxygen, allowing the blood to pick up oxygen in the lungs and let go of oxygen in the tissues. Hemoglobin is also responsible for the red color of blood.
