Molecular composition of a bacterial cell


Note: bacteria are the smallest and "simplest" cells. Their composition is perhaps a better gauge of the indispensable chemical makeup of "the cell" than might be a specialized human cell.

Component
% of total weight
Approx. # of molecules/cell
# of different kinds
Water
70%
40,000,000,000 1
DNA
1%
1-4 1
RNA
6%
500,000 3000
Proteins
15%
1,000,000 3000
Nucleotides & precursors
0.4%
12,000,000 200
Amino acids & precursors
0.4%
30,000,000 50
Carbohydrates (polysaccharides & precursors)
3%
250,000,000 200
Lipids
2%
25,000,000 50
Ions
1%
250,000,000 20
Waste products & intermediates
0.2%
15,000,000 200