9595.361 The minimum mass of the protein would be a molecule with exactly 1 iron atom in it. Looking up the atomic weight of iron, you get 55.845. So you can create the equation 0.582% x = 55.845 Get rid of the percent 0.00582 x = 55.845 Divide both sides by 0.00582 x = 9595.361 So the minimum molecular mass of the protein will be 9595.361