GENERAL MICROBIOLOGY - T.P. Pyrog - 2004

4. CHEMICAL COMPOSITION OF THE BACTERIAL CELL

4.2. ELEMENTAL COMPOSITION OF THE CELL

Bacterial Cells comprise the following elements (% of dry weight): carbon — 50; oxygen — 20; nitrogen — 10-14; hydrogen — 8; phosphorus — 3; sulfur, potassium, sodium — 1; calcium, magnesium, chlorine — 0.5; iron — 0.2; remaining elements — approximately 0.3.

Carbon, oxygen, hydrogen, and nitrogen serve as the principal Components of the Organic compounds that build The Cell. Sulfur is essential for the Synthesis of the Amino Acids Cysteine and Methionine, as well as certain Coenzymes. Phosphorus is a constituent of Nucleic Acids, Phospholipids, Teichoic Acids, and NUCLEOTIDES such as ATP, GTP, NAD, and FAD. Potassium, magnesium, calcium, and iron ions act as enzyme Cofactors and components of metal complexes. For instance, the majority of biologically active phosphate esters exist within cells as complexes with magnesium. Iron ions are incorporated into components of the Respiratory Chain (Cytochromes, iron-sulfur Proteins).