Protein Metabolism
No longer can we, like the older physiologists, envisage protein as being absorbed as such from the alimentary canal and forthwith incorporated with the body tissue, for the researches of Fischer have revealed that the complex protein molecule must previously undergo complete disruption into the a-amino-acids, its ultimate “building stones,” this through the hydrolytic action of the digestive enzymes of the alimentary tract. The fact that Fischer[6] was able to maintain nitrogen equilibrium in animals fed with completely digested protein mixtures is, of course, direct evidence in favour of his contention, viz., that proteins undergo disruption into amino-acids.