TY - JOUR T1 - MOlecular weight of proteins Y1 - 1929/01/19 N1 - 10.1001/jama.1929.02700290043015 JO - Journal of the American Medical Association SP - 233 EP - 234 VL - 92 IS - 3 N2 - An axiom in physiology asserts that without protein life is impossible. This substance is the basic material in the composition of cells which, in turn, are the units from which and by which tissues are made. It is rather surprising that, compared to the present status of the knowledge of other types of compounds, so little is known about the fundamental features of the chemical composition of the proteins. The conception of their structure has not passed the stage of hypothesis, and additional proofs for the most acceptable of these are difficult to adduce.1 Likewise the study of the molecular weights of proteins has been slow in developing. However, there is nothing mysterious about this class of compounds. The difficulties that beset investigators are largely due to two factors: the chemical lability of the proteins and the complex, colloidal behavior which is characteristic of these substances; the trend of SN - 0002-9955 M3 - doi: 10.1001/jama.1929.02700290043015 UR - http://dx.doi.org/10.1001/jama.1929.02700290043015 ER -