21. Like other mucins , MUC-4 is a high-molecular weight glycoprotein. 22. Surface mucous cells have large quantities of mucin granules in their rough endoplasmic reticulum. 23. Each species possesses mucin -secreting submaxillary glands. 24. This indicates that mucin segments extend into the ambient solution at a long distance. 25. Specialist microbes that break down mucin , survive on their host's carbohydrate excretions. 26. The mucin -like stalk permits it to bind to the surface of certain cells. 27. The physiological function of this protein may be related to its mucin -type character. 28. Secretory mucins are the main components of the mucous gel layer that coats the epithelium. 29. Being large glycoproteins, mucins have high carbohydrate content, contributing to their fibrous structure. 30. The secretion of mucin involves P2RY2 receptors found on the apical membrane of goblet cells.
