Your advisor has given you a tube of GMP that has been sitting in the freezer for many years and wants to know the concentration. There is one problem: the spectrophotometer in the lab has been 'optimized' for use with proteins and only measures at 280 nm. You decide to give it a try. After getting and absorbance reading of 0.2, what is the concentration of GMP in the tube (assuming a 1 cm path length).