Transport of amino acids into and across cells.

T HIS SyfllpOSiUIfl is concerned with the massive disappearance of nutrients from the alimentary canal and their reappearance in various body channels ; more l)articUlarly with the intervening events and their disorders. What is the nature of these events? We are dealing with the problem of transport, usually of structurally-specific mediated transport, and often active transport. An axiom of biochemical advance is that a phenomenon should be studied in simple form, if possible in isolated form, in order to understand it. Do the chemical reactions of transport across the intestinal mucosa exist in simpler form? We will try to show that the simpler, probably universal phenomenon of active transport into cells is fully capable of producing active transport across cells.