Molecular weight water-soluble organic matter

Water soluble proteins are present in shells in the amount of 0.1 to 27< of the total organic matter. EDTA treatment will release additional increments and in Mercenaria mercenaria shells, 15% of the total is EDTA extractable228. The material represents a highly sulfated glycoprotein with a molecular weight in the order of 160000. 

The second reason that bisulfite compounds are useful is that they are soluble in water. Some small (that is, low molecular weight) aldehydes and ketones are water-soluble—acetone is an example. But most larger (more than four or so carbon atoms) aldehydes and ketones are not. This does not usually matter to most chemists as we often want to carry out reactions in organic solvents rather than water. But it can matter to medicinal chemists, who make compounds that need to be compatible with biological systems. And in one case, the solubility of bisulfite adduct in water is literally vital. 

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