hemoglobincontaining

Hemoglobin-containing is an adjective used to describe cells, tissues, or substances that include hemoglobin, the iron-containing protein responsible for oxygen transport in many animals. In most vertebrates, the primary hemoglobin-containing cells are erythrocytes (red blood cells), which are filled with hemoglobin and, in mammals, lack a nucleus.

Hemoglobin itself is a protein composed of four globin chains (two alpha and two beta in adult human hemoglobin) and four heme groups. Each heme group can bind one molecule of oxygen, enabling oxygen uptake in the lungs and delivery to tissues. Hemoglobin also binds carbon dioxide for transport back to the lungs for excretion. The oxygen affinity of hemoglobin is modulated by factors such as pH, temperature, and 2,3-bisphosphoglycerate (2,3-BPG).

Clinically, the level of hemoglobin in blood is measured as hemoglobin concentration and is used to diagnose conditions like anemia (low hemoglobin) or polycythemia (high hemoglobin). In humans, red blood cells have a typical lifespan of about 120 days, and disorders affecting hemoglobin structure or production (such as thalassemias or sickle cell disease) can impair oxygen transport.

Outside human blood, other organisms possess hemoglobin-like proteins or hemoglobin-containing tissues. Leghemoglobins in legume root nodules help protect nitrogenase from oxygen, while many bacteria and some invertebrates express hemoglobins or hemoglobin-related proteins for oxygen transport or protection against reactive gases. Myoglobin is a related but distinct oxygen-binding protein found in muscle tissue.