Oxyhaemoglobin

Oxyhaemoglobin is the bright red substance formed when haemoglobin binds with oxygen in the lungs. Haemoglobin is a protein found in red blood cells that is responsible for transporting oxygen from the lungs to the body's tissues. When oxygen molecules enter the bloodstream, they readily attach to the iron atoms within the haemoglobin molecules. This binding process results in a conformational change in the haemoglobin molecule, leading to the characteristic red colour of oxygenated blood.

The binding of oxygen to haemoglobin is reversible. As blood circulates through tissues where oxygen levels are lower, such as active muscles or organs, the oxyhaemoglobin releases its oxygen. This release is driven by the concentration gradient of oxygen, allowing the tissues to utilize the oxygen for cellular respiration. The deoxygenated haemoglobin then returns to the lungs to pick up more oxygen, continuing the vital cycle of gas exchange. The efficiency of this oxygen transport is crucial for sustaining life. Factors like pH, temperature, and the concentration of carbon dioxide can influence the affinity of haemoglobin for oxygen, a phenomenon known as the Bohr effect.