How Big Are Proteins?

Proteins of different kinds and functions vary widely in the number of amino acids of which they are composed.

But three hundred amino acids is a typical natural protein length and size.

And a typical average natural protein mass can be calculated based on that length and size by multiplying the average mass of an amino acid (see "What Are the Protein Monomers") times three hundred, and then subtracting the combined masses of the two hundred and ninety-nine water molecule equivalents lost ("What Are the Protein Monomers"), amounting to about 6.16 * 10^-20 gram, about sixty zeptograms, a little over two thousand times the mass of a water molecule.

And the corresponding typical average natural protein gram number, the number of such proteins contained in one gram thereof, can be calculated by dividing that mass into one gram, giving about 1.62 * 10¹⁹ or about sixteen quintillion such proteins per gram.