Which pigment is an iron-containing pigment found in red blood cells that binds with oxygen to form oxyhaemoglobin?

• A. Haemoglobin
• B. Myoglobin
• C. Mitochondria
• D. Oxyhaemoglobin Dissociation

Answer: (A)

The pigment is haemoglobin. It is the iron-containing protein inside red blood cells that reversibly binds oxygen, forming oxyhaemoglobin in the lungs so oxygen can be carried to tissues and released where needed. Haemoglobin has iron in its heme groups, allowing up to four oxygen molecules to bind. Myoglobin is another oxygen-binding protein but sits in muscle tissue (not in red blood cells) and forms oxymyoglobin, not oxyhaemoglobin. Mitochondria are cell structures involved in energy production, not pigments. Oxyhaemoglobin dissociation describes the release of oxygen from haemoglobin, not a pigment itself.