Main organs of the human digestive system participate in the following order in process of digestion:
Mouth, oesophagus, stomach, small intestine, large intestine, rectum and anus.
Digestion of carbohydrates takes place in following manner: Major carbohydrates that we take are starch, sucrose, lactose.
Digestion of carbohydrates takes place in mouth and stomach and in following steps:
•When food is chewed it is mixed with the ptyalin secreted in mouth and break down carbohydrates in small products. Only 5% of digestion takes place here.
•Then digestion continues in stomach where gastric and acidic secretions of stomach cause 30 to 40% of digestion.
•As partially digested food empties from stomach to duodenum further digestion is caused by pancreatic amylase which converts them into small polymers.
•Final digestion is caused by small intestine where villi contain enzymes like sucrase, lactase, maltase and dextrinase which cause their final digestion by converting them into constituent monosaccharides.
Digestion of proteins takes place in the following manner:
Digestion of proteins begins in stomach and takes place in following manner:
Pepsin enzyme is responsible for the protein digestion in stomach. It is activated at acidic pH and cause little bit digestion of proteins thereby converting them into small molecules.
Further digestion takes place by pancreatic juices. Pancreatic enzymes like trypsin, chemotrypsin are release by pancreas in small intestine where these enzymes broke down protein further into very small molecules.
Further peptidase of small intestine break down small molecules of protein further and absorption takes place and digestion of proteins gets completed.
Figure : Digestion of proteins.