Tag: parts of the digestive system

The digestion of the food starts at the mouth where the enzyme amylase is secreted which digests the start that is present in the food and converts it into maltose. From there through the esophagus the food arrives in the stomach where it is stored for 4 hours and mixed with acid. The food when arrives at the stomach where the wall of the stomach secrets HCl with a pH of 1.8. This acid activates the inactive pepsinogen enzyme and forms active pepsin which digests proteins and converts them into proteases and peptides. From here the food moves to the small intestine where secretion from the liver and pancreas reach through a hepatopancreatic duct which is alkaline in nature and neutralizes the acidic food that comes from the stomach. Here majority of the digestion of protein to amino acids, fat to fat droplets, polysaccharides to monosaccharides etc takes place.

In the stomach, proteins are hydrolysed by enzyme pepsin. It begins the digestion of proteins by splitting them into peptones (see peptidase). It is produced by the action of $HCl\left( { H }^{ + } \right) $ on pepsinogen, which is secreted by the stomach in gastric glands.

Only some chemicals medicines and alcohol are absorbed in oro pharyngeal cavity. In the stomach, absorption of water, some salts, alcohol and glucose takes place, complete absorption of alcohol takes place in the stomach. Thus, carbohydrates, proteins and fats will remain in alimentary canal for complete digestion and when broken down completely in small intestine then only they will be absorbed in the intestine but beer will not be digested in alimentary canal and directly absorbed in the stomach.

Carbohydrate digestion starts in the mouth as salivary amylase is present there. Protein digestion starts in the stomach as protein digesting enzymes is present in stomach and fat digestion occurs in the small intestine.

Rennin is a milk-curdling enzyme, that occurs in the gastric juices of infants and is also contained in the rennet produced in the stomach of calves and other ruminants. It is an endopeptidase, that converts casein to paracasein and was formerly used extensively as a curdling agent by the cheese industry. 

Stomach in vertebrates is the main site for digestion of proteins. Pepsin is the chief proteolytic enzyme of stomach secreted in the inactive form called as pepsinogen. The pepsinogen is activated to pepsin in presence of hydrochloric acid secreted in stomach by oxyntic or parietal cells. The optimum pH for activity of pepsin is 1.8.

Hydrochloric acid (HCl) converts pepsinogen to pepsin which breaks down proteins to peptides. HCl maintains a pH in the stomach of approximately 2.0. It also dissolves food and kills microorganisms. Without enough HCl, pepsinogen is no converted to pepsin which do not allow the breakdown of proteins

Stomach in vertebrates is the main site for digestion of proteins. Pepsin is the chief proteolytic enzyme of stomach secreted in the inactive form called as pepsinogen. The pepsinogen is activated to pepsin in presence of hydrochloric acid secreted in stomach by oxyntic or parietal cells. The optimum pH for activity of pepsin is 1.8.