dehühemoglobiin

Dehühemoglobiin, also known as deoxyhemoglobin, is the protein molecule in red blood cells that, when not bound to oxygen, is referred to as deoxyhemoglobin. It is the form of hemoglobin that is deoxygenated. Hemoglobin is a complex molecule composed of four protein subunits, typically two alpha chains and two beta chains, each containing a heme group. The heme group consists of a porphyrin ring with an iron atom at its center. In oxygenated hemoglobin (oxyhemoglobin), the iron atom is in a ferrous (Fe2+) state and is capable of reversibly binding to an oxygen molecule.

When hemoglobin releases oxygen to the tissues, it transitions to its deoxyhemoglobin form. This deoxygenation process occurs in areas of the body where oxygen concentration is low, such as in metabolically active tissues. The binding affinity of hemoglobin for oxygen is significantly influenced by factors like pH, carbon dioxide concentration, and temperature, all of which are typically altered in active tissues. The change in conformation upon deoxygenation causes a slight rearrangement of the protein subunits, which affects its spectral properties. Deoxyhemoglobin absorbs light differently than oxyhemoglobin, particularly in the red and infrared spectrum, a principle exploited in pulse oximetry for measuring blood oxygen saturation. The majority of the iron in hemoglobin remains in the ferrous state whether oxygen is bound or not.