Question

we ate bread in the morning starting from the mouth explain ho9w it was digested

Answer 1

In ideal circumstances a fairly large proportion of a given quantity of bread is digested in the mouth. Starch or carbohydrate is quite incapable of absorption until it has been rendered soluble, and this is effected by the action of saliva, which converts it first into dextrin and subsequently into maltose. Pavlov demonstrated that the chewing of fresh moist bread produced no secretion of saliva worth mentioning, but dry bread caused the saliva to flow in large quantities. Stale bread, crust of bread, toast, zwieback (double-toasted bread), and plenty of biscuit compel fairly prolonged mastication with plenty of saliva, while soft bread is usually bolted with no production of digestive juice of any consequence.

On reaching the stomach this digestion of the starch by saliva still goes on until it has been neutralised by the outflow of gastric juice in from half to three-quarters of an hour, and then the protein is attacked by the pepsin and hydrochloric acid. Bread provokes a secretion of five times more pepsin than an equivalent quantity of milk, and four times more than meat, but a much smaller quantity of hydrochloric acid so as to interfere as little as possible with the alkaline saliva. Gastric juice is only able to digest proteins, and in about two hours and a half a slice of bread is ready to leave the stomach.

The various digestive fluids of the intestine soon complete the digestion of the starch and protein and the small quantity of fat contained in bread, and then absorption into the blood takes place. Up to this point there is practically no difference between white and wholemeal bread, but the superiority of the former now becomes apparent. It is easy to understand that no matter how well digested an article of diet may be, it is quite incapable of nourishing the body until it has been absorbed, and in this connection white bread is paramount, for only 3 per cent. of its carbohydrates, 20 per cent. of its proteins, 25 per cent. of its mineral matter, and 4 1/2 per cent. of its total solids escape absorption - even when it is given alone. When mixed with other foods, for example milk, a very much larger proportion is utilised for the nutrition of the body. When we compare these really excellent results with wholemeal, we find that 6 per cent. of its carbohydrates, nearly 30 per cent. of its proteins, over 50 per cent. of its mineral matter, and 14 per cent. all told of its total solids are actually unabsorbed.

Answer 2

First we chew it which mixes from saliva, then it passes from the oesophagus and mixes with hydrochloric acid and other digestive juices and then goes into small intestine which extracts the proteins and minerals. The proteins and minerals gets mixed in the blood by the cells and substances which are not needed goes into large intestine and gets excreted. This process takes time depending on the type of bread eaten.

hope it helps,
Garvaditya Verma