Nitrogen can be a component of proteins, proteides and non-protein nitrogen. Protein consists of only polypeptides while proteides are composed of at least one protein and another compound which is a non-protein, e.g. phospho-proteides = protein + phosphoric acid.

For on a day, when Cupid kept his court, / As he is wont at each Saint Valentide, / Vnto the which all louers doe resort, / That of their loues successe they there may make report.

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Hawthorne Effect: This completely un-self-explanatory and technical sounding term describes a discovery that is basic to psychological experimentation.