restriction. n. 1. something that restricts; a restrictive measure, law, etc. 2. the act of restricting or the state of being restricted. 3. (Logic) logic maths a condition that imposes a constraint on the possible values of a variable or on the domain of arguments of a function.
The primitive gut that forms during gastrulation in the developing embryo is known as the archenteron or the digestive tube.It develops into the digestive tract of an animal.ach is controlled by the dorsal blastopore, and primitive node (also known as Hensen's node), respectively. During Gastrulation, the Archenteron develops into the digestive tube, with the blastopore developing into either the mouth (Protostome) or the anus (Deuterostome).
Digestive enzymes are released in inactive forms called zymogens. This is necessary to prevent the digestive enzymes from digesting the cells that produce them. In a zymogen, a peptide blocks the active site of the enzyme.Cleaving off this peptide activates the enzyme.ctivation of pepsinogen in the stomach. The peptidase in the stomach is pepsin. Pepsin works optimally in the acidic environment of the stomach, being active at pH 2-3, but becoming inactivated when the pH is above 5. The chief cells at the base of the gastric glands secrete the zymogen, which is called pepsinogen.