Tag: parts of the digestive system

Questions Related to parts of the digestive system

Digestion of protein takes place in

parts of the digestive system digestive system of human human digestive system digestion and absorption biology nutrition deficiency diseases digestive system

  1. Duodenum and stomach

  2. Stomach and oesophagus

  3. Small and large intestine

  4. Intestine and rectum

Show answer
Correct Option: A

Which of the following is incorrect regarding the given digestion and absorption of protein?

parts of the digestive system digestive system of human human digestive system digestion and absorption biology nutrition deficiency diseases digestive system

  1. The breakdown of proteins to peptides is catalyzed by pepsin in the stomach and by the pancreatic enzymes trypsin and chymotrypsin in the small intestine.

  2. Peptides are broken down into amino acids by pancreatic carboxypeptidase and intestinal aminopeptidase.

  3. Small peptides consisting of two or three amino acids can diffuse through the epithelial cell and broken down into carbon dioxide and ammonia which are released into the blood.

  4. None of these

Show answer
Correct Option: B
Explanation:

  • Digestion of protein is initiated in the stomach by the enzyme pepsin.
  • In the small intestine, further digestion is done by trypsin, chymotrypsin, and carboxypeptidase into dipeptidase that releases from the pancreas.
  • Dipeptidase are broken into amino acids by intestinal dipeptidase.
  • These amino acids are absorbed actively by walls of intestine and release in the bloodstream.
  • These are utilized by tissues and broken down into carbon dioxide and ammonia.
  • Proteins require maximum energy to digest.

So the correct option is 'Peptides are broken down into amino acids by pancreatic carboxypeptidase and intestinal aminopeptidase.'

How does pepsinogen change into its active form?

parts of the digestive system digestive system of human human digestive system digestion and absorption biology nutrition deficiency diseases digestive system

  1. In the presence of hydrochloric acid

  2. In the presence of trypsin

  3. In the presence of  bile

  4. In the presence of carboxypeptidae

Show answer
Correct Option: A
Explanation:

 Parietal cells of stomach secrets hydrochloric acid which convert inactive pepsinogen to partially active pepsinogen, partially activates pepsinogen then cleaves the peptide from other pepsinogen molecules to form active pepsin which converts protein into proteases and peptides.

So, the correct answer is 'In the presence of hydrochloric acid'.

Which of the following is the correct matching of the site of action on the given substrate, the enzyme acting upon it and the end product?
(i) Small intestine: Protein $\xrightarrow{Pepsin}$ Amino acid
(ii) Stomach : Fat $\xrightarrow{Lipase}$ Micelles
(iii) Duodenum : Triglycerides $\xrightarrow{Trypsin}$ Monoglyceride 
(iv) Buccal cavity : Starch $\xrightarrow{Amylase}$ Disaccharide
(v) Jejunum: Peptones $\xrightarrow{Pepsin}$ Amino acid
(vi) Buccal cavity : Starch $\xrightarrow{Amyloglycerate}$ Maltose

parts of the digestive system digestive system of human human digestive system digestion and absorption biology nutrition deficiency diseases digestive system

  1. (i),(ii) and (iii) are correct

  2. (iv) only 

  3. (iv) and (v) are correct

  4. All are correct

Show answer
Correct Option: B
Explanation:

(i) Pepsin digest protein in the stomach.

(ii)Lipase digest emulsified fat in the intestine.
(iii)In duodenum trypsin digest protein or dipeptides.
(iv) Starch is digested into maltose by salivary amylase in the buccal cavity.
(v)Pepsin digest protein in the stomach.
(vi) Starch is digested into maltose by salivary amylase in the buccal cavity.
So the correct option is '(iv) only '

Read the given statements and select the option that correctly identifies them as true or false
1) Insulin has no effect on absorption of glucose from gastrointestinal tract
2) Fat absorption is greatest in the upper part of the small intestine
3) most vitamins are absorbed in the ileum

parts of the digestive system digestive system of human human digestive system digestion and absorption biology nutrition deficiency diseases digestive system

  1. True

  2. False

Show answer
Correct Option: A
Explanation:
1) Insulin has no effect on the absorption of glucose from the gastrointestinal tract as it increases the amount of glucose absorption when its concentration increase in blood.
2) Fat absorption is greatest in the upper part of the small intestine because in duodenum bile emulsifies it and form micelles which are absorbed form.
3) Most vitamins are absorbed in the ileum.
So the correct option is 'True'.

What is common among amylase, renin and trypsin?

parts of the digestive system digestive system of human human digestive system digestion and absorption biology nutrition deficiency diseases digestive system

  1. They are proteins

  2. All these are proteolytic enzymes

  3. These are produced in stomach

  4. These act at the pH of less than 7

Show answer
Correct Option: A
Explanation:

A) Amylase is produced by buccal cavity, pancreas and intestine and digest starch.

B) Renin is produced by the stomach and helps in the digestion of milk in infants.
C) Trypsin is produced by the pancreas and helps in the digestion of protein.
But one thing is common in all the above three is that they are made up of proteins.
So, the correct option is 'They are proteins'.

If PH of stomach is made 7, which component of the food would be affected?

parts of the digestive system digestive system of human human digestive system digestion and absorption biology nutrition deficiency diseases digestive system

  1. Starch

  2. Proteins

  3. Fat

  4. Sucrose

Show answer
Correct Option: B
Explanation:

If pH of the stomach is made 7 protein digestion will affect as pepsin works ar pH of 2 to 3 and enzymes are highly precise about there function so it does not activate.

So the correct option is 'proteins'.

Chief function of HCl is ________

parts of the digestive system digestive system of human human digestive system digestion and absorption biology nutrition deficiency diseases digestive system

  1. To maintain a low pH to promote growth of microorganism

  2. To facilitate absorption

  3. To maintain low pH to activate pepsinogen to form pepsin

  4. To dissolve enzyme secreted in stomach

Show answer
Correct Option: C
Explanation:

The chief function of HCl in the stomatch is to maintain low pH to activate pepsinogen to form pepsin. HCl converts inactive pepsinogen into the active pepsin enzyme. The pepsin helps in the breaking down proteins in the stomach. HCl also kills bacteria that enter the stomach. It also helps in digestion of  other foods in the stomach.

Thus, the correct answer is 'To maintain low pH to activate pepsinogen to form pepsin.'

Which of the following statements are correct about the function of the acidic environment of the stomach?
(i) Provides defence against bacteria entering the digestive system
(ii) Converts pepsinogen to pepsin
(iii) Assists the breakdown of cells in animal and plant food stuffs

parts of the digestive system digestive system of human human digestive system digestion and absorption biology nutrition deficiency diseases digestive system

  1. ii only

  2. i and ii only

  3. ii and iii only

  4. i, ii, and iii

Show answer
Correct Option: B
Explanation:

The HCl is secreted by the oxyntic cells in the stomach. The HCl provides the acidic medium in the stomach that is responsible for converting the inactive pepsinogen to the active pepsin. Pepsin is required for protein digestion. The acidic medium provides defence against bacteria entering the digestive system.

Hence, the correct answer is 'i and ii only'

Which of the following enzymes is not useful in the digestion of proteins?

parts of the digestive system digestive system of human human digestive system digestion and absorption biology nutrition deficiency diseases digestive system

  1. Chymotrypsin

  2. Pepsin

  3. Trypsin

  4. Lipase

Show answer
Correct Option: D
Explanation:
  • Protein digestion occurs in the stomach and duodenum in which 3 main enzymes: Pepsin, trypsin and chymotrypsin.
  •  pepsin secreted by the stomach and trypsin and chymotrypsin secreted by the pancreas, break down food proteins into polypeptides that are then broken down by various exopeptidases and dipeptidases into amino acids. 
  • Hence, Lipase enzymes are not useful in the digestion of proteins.
  • So, the correct answer is 'Lipase'.