Well, you have a point there. Drinking is not an injection onto the bloodstream.
The digestive process brakes the incoming protein down into amino acids. The amino acids are then linked up again to form a protein. The combinations of amino acids that go into forming a protein don't have to be the same as the protein they came from.
But, at least the parts are there.
Alex
"There is a cult of ignorance in the United States, and there has always been. The strain of anti-intellectualism has been a constant thread winding its way through our political and cultural life, nurtured by the false notion that democracy means that "my ignorance is just as good as your knowledge."
-- Isaac Asimov