Question

How many oxygen molecules can one hemoglobin carry.

Answer 1

Oxygen binds reversibly to harem, so each hemoglobin molecule can carry up to four oxygen molecules. Hemoglobin is an allosteric protein; the binding of oxygen to one harem group increases the oxygen affinity within the remaining harem groups.

Answer 2

The hemoglobin molecule has four binding sites for oxygen molecules: the iron atoms in the four heme groups. Thus, each Hb tetramer can bind four oxygen molecules.