Q1. A red blood cell must squeeze through narrow blood capillaries without rupturing its membrane. The strength and flexibility of its plasma membrane depends on the dense cytoskeletal network that consists mainly of actin and spectrin molecules. A blood sample was analyzed to measure the intracellular actin concentration. Out of 10^10 red blood cells counted, 1 mg of actin was purified. Estimate the estimated millimolar concentration of actin in a red blood cell (the average volume of a red blood cell is 100 femtolitres and the actin coding DNA sequence is 1131 base pairs long). Calculations must be made assuming that the minimum significant number has four significant digits.

Q2. If all of phosphorus in a 3.00 gram sample of MgNH4PO4 is extracted and used to make a diphosphorus pentaoxide, what mass of P2O5 could be produced?