Composition of protein - Biomolecules
Composition of a protein changes with source. An estimated composition is as follows:
Carbon from 50-53%; hydrogen from 6-7%; oxygen from 23-25%; nitrogen from 16-17%; Sulphur about 1%. Other components can as well be exist, for example phosphorus (in nucleoproteins), iodine (in thyroid proteins) and iron (in haemoglobin).