lemoglobina

Lemoglobina is not a standard term in biology, and it most likely refers to hemoglobin, the oxygen-carrying protein of red blood cells, in languages or contexts where the spelling differs slightly. In scientific use, the term most commonly encountered is hemoglobina or hemoglobina/hémoglobine depending on the language.

Hemoglobin is a tetramer composed of four protein subunits, typically two alpha and two beta chains in adults, each with a heme prosthetic group containing iron in the ferrous (Fe2+) state. Each heme can reversibly bind one molecule of oxygen, enabling the protein to transport oxygen from the lungs to tissues and to carry carbon dioxide back to the lungs for exhalation. The binding of oxygen is cooperative, giving a sigmoidal oxygen-hemoglobin dissociation curve and allowing efficient loading in the lungs and unloading in tissues where it is needed.

In humans, there are several hemoglobin types, including HbA (adult), HbA2, and HbF (fetal). The proportion of these variants changes with development and health. Abnormalities in hemoglobin can lead to disorders such as sickle cell disease, various forms of thalassemia, or methemoglobinemia. Hemoglobin levels are a standard measure in blood tests and reflect aspects of red blood cell mass and oxygen-carrying capacity.

Synthesis occurs in bone marrow, and degradation takes place mainly in the spleen and liver, with iron recycled for new hemoglobin synthesis.