Question 1

How are fats digested in our bodies? Where does this process take place?

Accepted Answer

Answer:Fat digestion takes place in the small intestine. The alkaline secretion of the liver, bile, is carried to the small intestine by the bile duct. The process starts with emulsification (break down) of large fat globules by the salt of bile into smaller micelles to facilitate further enzymatic reaction and digestion process. The fat-digesting lipase enzyme in pancreatic juice and intestinal juices digest the fat in micelles into triacylglycerols and then fatty acids and glycerol. These fat digestion products are then absorbed by the intestinal mucosa and are carried to tissues by the lymphatic system and blood where they either serve as energy fuel or are stored after re-esterification.

Question 2

Bile juice contains no digestive enzymes, yet it is important for digestion. Why?

Accepted Answer

Bile is a digestive juice secreted by the liver. Although it does not contain any digestive enzymes, it plays an important role in the digestion of fats. Bile juice has bile salts such as bilirubin and biliverdin. These break down large fat globules into smaller globules so that the pancreatic enzymes can easily act on them. This process is known as emulsification of fats. Bile juice also makes the medium alkaline and activates lipase.

Question 3

Name any three glands associated with digestion in humans. Write the names of enzymes secreted by them.

Accepted Answer

The three glands associated with digestions in humans are 1) The mouth which consists salivary gland and secretes saliva2) Stomach which consists gastric glands which secrets Gastric Juices3) Liver and Pancreas which secretes- Bile juice and Pancreatic juices respectively.

Question 4

What are the functions of gastric glands present in the wall of the stomach?

Accepted Answer

Gastric glands are present in the wall of the stomach which secrete gastric juice containing the digestive enzyme like pepsin, renin, mucus and HCl. The function of these enzymes are as follows:(a) Production of pepsin enzyme that digests proteins.(b) Secretion of mucus for the protection of inner lining of the stomach.(c) Secretion of HCl, which kills the bacteria and foreign harmful organisms in the food. Thus, the correct answer is option D.

Question 5

Trypsin differs from pepsin because it digests

Accepted Answer

A) Correct option- DB) Explanation of correct option Both pepsin and trypsin are proteolytic enzymes. Pepsin is secreted in the stomach, whereas trypsin is a component of pancreatic juice. Pepsinogen is activated to pepsin in the stomach on exposure to hydrochloric acid. The optimum pH for the activity of pepsin is 1.8. Pepsin is a strong endopeptidase and breaks proteins into smaller molecules like peptones, proteOses and peptides. Trypsinogen is activated by the action of enterokinase into active trypsin. Enterokinase is secreted by the duodenal mucosa for activation of trypsinogen. Trypsin and chymotrypsin are endopeptidase types of enzymes and are active in alkaline pH i.e., 7.5 to 8. They dissociate proteins into peptones and proteoses

Question 6

If salivary amylase is lacking in the saliva, which of the following events in the mouth cavity will be affected?

Accepted Answer

Correct Option: BExplanation:Amylase is the enzyme that catalyses the hydrolysis of starch into simple sugars. So if salivary amylase is lacking in saliva, the breakdown of starch is affected. Other phenomena such as protein breakdown to amino acids by protease enzyme and fat breakdown by bile in the small intestine. Whereas vitamins are absorbed by the small intestine.Hence, if salivary amylase is lacking in the saliva, then in the mouth starch will not break down in sugar.

Question 7

What are final products of carbohydrates proteins and fats after their digestion?

Accepted Answer

Explanation:Carbohydrates are processed in three places: the mouth, the stomach, and the small intestine. Carbohydrase enzymes are responsible for breaking down carbohydrates into monosaccharides.Proteins are digested in the stomach and small intestine. During digestion, proteins are broken down into amino acids.Lipids (fats and oils) are broken down in the small intestine. The enzyme lipase is responsible for breaking down lipids into fatty acids and glycerol.

Question 8

What is the role of HCl in our stomach?

Accepted Answer

HCl is one of the gastric juices secreted by stomach.HCl converts the inactive enzyme pepsinogen into its active form pepsin. Pepsin digests proteins and breaks them into amino acids. HCl also kills harmful pathogens or particles in our food when it reaches the stomach through the gastrointestinal duct.

Question 9

What is the role of acid in our stomach?

Accepted Answer

The gastric juice is made up of hydrochloric acid, pepsinogen and other digestive enzymes, gastrin, mucus, and bicarbonates. It has a pH ranging from 1 to 2. Its low pH is essential in activating digestive enzyme such as pepsinogen and convert it into the active pepsin, a Proteolytic activity of pepsin and in destroying various pathogens. Thus, the correct answer is option D.

Question 10

Emulsified fats are digested by

Accepted Answer

The breakdown of fat globules in the duodenum into the droplets, which provide a larger surface area on which the enzyme lipase can act to digest the fats into the fatty acids and glycerol is called the emulsification of fats. Now, these emulsified fats are acted upon by the pancreatic lipase and intestinal lipase to break down into fatty acids and glycerol.Thus, the correct answer is option D.