Starch is hydrolyzed in the mouth by:
Ans. (b) PtyalinRef: Guyton's physiology 11th ed./ 793* Saliva contains two major types of protein secretion:# Serous secretion- contains ptyalin, an enzyme for digesting starches.# Mucus secretionGlandSecretionContentFunctionParotid glandSerous typePtyalinDigest starchesSubmandibular glandSerous and mucous typeMucinLubricating and for surface pro- tective purposesBuccal glandOnly mucusMucinLubricating* Saliva has a pH between 6.0 and 7.0, a favorable range for the digestive action of ptyalin.* The activity of the salivary amylase is blocked by acid of the gastric secretions due to low pH.* But before food and its accompanying saliva become completely mixed with the gastric secretions, as much as 30 to 40% of the starches will have been hydrolyzed mainly to form maltose.* In small intestine the remaining starch Digestion takes place by Pancreatic Amylase. Pancreatic secretion is almost identical in its function with the a-amylase of saliva but is several times more powerful.* Hence, within 15 to 30 minutes after the chyme empties from the stomach into the duodenum and mixes with pancreatic juice, nearly all the carbohydrates will have become digested.
Mucin
Ptyalin
Pancreatic amylase
Lipase
Digestion and Absorption