A. A source of energy.
B. A source of carbon (CO2 or organic molecules)
C. A source of nitrogen via nitrate salts for amino acids, purines, and pyrimidines.
D. A source of sulfur for some amino acids and some coenzymes.
E. Vitamins for coenzymes
F. A source of phosphorous (phosphates) for ATP and nucleic acids.
1. Na+, Ca++, etc.
2. Include trace element metals for cofactors (zinc, Cu, etc).
H. Water (keeps molecules in solution, hydrolysis)