The function is determined by shape. The protein is determined by its primary structure which is the sequence of amino acids. Amino acid sequence is determined by nucleotides in the gene (DNA)
This means for every number of Carbon (C) atoms, there are twice as many Hydrogen (H) atoms with an additional two added onto that.
Therefore, if there is one Carbon Atom, and we multiply that by two, and then add an additional two, we get 4 Hydrogen atoms, so CH4, which is our first Formulae
Secondly, if we have eight Carbon Atoms, and we multiple that by two (16), and then add an additional two, we get 18 Hydrogen atoms, so C8H18, which is our second Formulae
The other Formulas do not follow this 'General Formula'
