Oxygen Capacity of Red Blood Cells: Calculation for a 71kg Man

The amount of oxygen in the red blood cells of a 71 kg man can be calculated if we know the total amount of hemoglobin in the body and the oxygen-binding capacity of hemoglobin.

The average hemoglobin concentration in a healthy 71 kg man is approximately 15 g/dL. The total blood volume of a 71 kg man is about 5 liters, which means that the total amount of hemoglobin in the body is:

15 g/dL * 5 L * 10 dL/L = 750 g

Each hemoglobin molecule can bind up to four oxygen molecules. The molecular weight of hemoglobin is approximately 64,500 g/mol, and the molecular weight of oxygen is 32 g/mol. Therefore, the oxygen-binding capacity of 1 mole of hemoglobin is:

4 molecules O2 / 64,500 g/mol hemoglobin * 32 g/mol O2 = 2 moles O2 / mol hemoglobin

To calculate the total amount of oxygen in the red blood cells of the 71 kg man, we need to multiply the total amount of hemoglobin by the oxygen-binding capacity of hemoglobin:

750 g hemoglobin * 2 mol O2 / mol hemoglobin = 1500 mol O2

Therefore, if all hemoglobin molecules were saturated, the red blood cells of a 71 kg man would contain 1500 moles of oxygen.