The mechanism that protects normal pancreas from autodigestion is :

Ans. is 'c' i.e. proteolytic enzymes secreted in inactive form The pancreatic enzymes have the capability of digesting the pancreas itself (mainly proteases)(Auto digestion of pancreas is considered to be the main pathogenic mechanism for pancreatitis)Normally, auto digestion of pancreas is prevented by several means :The enzymes are synthesized as inactive pro enzymes (with the exception of amylase and lipase)They are sequestered in membrane bound zymogen granules in acinar cellsActivation of pro enzymes requires conversion of inactive trypsinogen to active trypsin by duodenal enteropeptidaseTrypsin inhibitors are present within acinar and ductal secretionsIntra pancreatic release of trypsin activates an enzyme or enzymes that degrades other enzymes to inert products.Lysosomal enzymes are capable of degrading zymogen granules when normal acinar secretion is impaired or blocked.Acinar cells are remarkably resistant to the action of trypsin, chymotrypsin and phospholipase A2Regarding option V pancreatic enzymes require alkaline medium for their activity so bicarbonate secretion will help in their activity.