13. Red blood cells have a volume of ~86 fL. If the concentration of hemoglobin in red cells is ~330 g/L and its Mr is 64,500 a) How many hemoglobin molecules are there in a red blood cell? b) In the generation of a red blood cell, the synthesis of all the hemoglobin molecules in the cell takes about 40 h. How many hemoglobin molecules are synthesized in one second per red cell? c) How many subunits (monomers) of hemoglobin are produced in one minute?