MICROANATOMY

Detailed explanation-1: -Hemoglobin (Heme + Globin) The protein hemoglobin is a molecule which is responsible for carrying almost all of the oxygen in the blood. It is composed of four subunits, each with a heme group plus a globin chain. The heme group is composed of a porphyrin ring which contains an iron (Fe) atom in its center.

Detailed explanation-2: -Oxygen binds reversibly to haem, so each haemoglobin molecule can carry up to four oxygen molecules. Haemoglobin is an allosteric protein; the binding of oxygen to one haem group increases the oxygen affinity within the remaining haem groups.

Detailed explanation-3: -Each polypeptide is associated with haem, which is the prosthetatic group that mediates reversible binding of oxygen by haemoglobin. It contains a ferrous (Fe2+) ion.

Detailed explanation-4: -Answer and Explanation: Answer: Hemoglobin. The iron-containing protein called hemoglobin binds to oxygen in the lungs and transports it to tissues throughout the body, where the oxygen is released.