3. For production of penicillin (C16H1804N2S) using a Penicillium mold, glucose (C6H12O6) is used as substrate and phenylacetic acid (C8H8O2) is added as precursor. The stoichiometry for the overall penicillin synthesis is: 1.67C6H12O6+2NH3 + 0.502 + H2SO4 + C8H8O2 →C16H18O4N2S+2CO2 + 9H2O The molecular weights of penicillin, glucose, and phenylacetic acid are 334.4, 180.2, and 136.2 g/mol, respectively. Batch fermentation for penicillin production is carried out in a 100-liter tank. Initially, the tank is filled with nutrient medium containing 50 g/l glucose and 4 g/1 phenylacetic acid, and the reaction is stopped when the glucose concentration is 5.5 g/1. When results from the fermentation process were analyzed, it was found that 24% of the glucose had been used for growth, 70% for cell maintenance activities (such as membrane transport and macromolecule turnover), and only 6% for penicillin synthesis. Determine: (a) What is the limiting substrate if NH3, O2, and H2SO4 are provided in excess? (b) the total mass of glucose used for growth. (c) the amount of penicillin produced (in moles and grams). (d) the final concentration of phenylacetic acid.