The gastric mucosa secretes the inactive enzyme pepsinogen and hydrochloric acid (HCl). In the presence of HCl, the active enzyme pepsin is produced. Pepsin digests proteins into shorter polypeptides. The high concentration of HCl from the parietal cells makes gastric juice very acidic, with a pH of less than 2.he gastric mucosa secretes the inactive enzyme pepsinogen and hydrochloric acid (HCl). In the presence of HCl, the active enzyme pepsin is produced. Pepsin digests proteins into shorter polypeptides. The high concentration of HCl from the parietal cells makes gastric juice very acidic, with a pH of less than 2.
Coral reef. Coral reef, ridge or hummock formed in shallow ocean areas by algae and the calcareous skeletons of certain coelenterates, of which coral polyps are the most important. A coral reef may grow into a permanent coral island.
The fringing reef is by far the most common of the three major types of coral reefs, with numerous examples in all major regions of coral reef development.HAT IS A LAGOON? - A lagoon-as used in the context of coral reef typology-refers to a comparatively wide band of water that lies between the shore and the main area of reef development, and contains at least some deep portions.