Tag: digestion and absorption

Questions Related to digestion and absorption

Which of these will leave the stomach first in man?

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

  1. Beer

  2. Proteins

  3. Fats

  4. Carbohydrates

Show answer
Correct Option: A
Explanation:

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.

The type of food which starts digesting in stomach is

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

  1. Fats

  2. Carbohydrate

  3. Protein

  4. All of the above

Show answer
Correct Option: C
Explanation:

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 found in  

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

  1. Liver

  2. Kidney

  3. Pancreatic juice

  4. Gastric juice in stomach

Show answer
Correct Option: D
Explanation:

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. 

Main function of HCl in stomach is to

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

  1. Activates amylase enzyme

  2. Facilitate absorption of food

  3. Dissolve enzymes

  4. Activate pepsinogen to pepsin

Show answer
Correct Option: D
Explanation:

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.

Therefore, the correct answer is option D.

If the stomach did not produce any hydrochloric acid, which enzyme will not function?

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

  1. Ptyalin

  2. Trypsin

  3. Pepsin

  4. Collagenase

Show answer
Correct Option: C
Explanation:

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

So, the correct answer is 'Pepsin'

Stomach in vertebrates is the main site for digestion of 

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

  1. Proteins

  2. Carbohydrates

  3. Fats

  4. Nucleic acids

Show answer
Correct Option: A
Explanation:

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.

A man sits down to eat a large steak. Concerned about heartburn, he takes several antacid tablets before eating so as to neutralize his stomach acid.
Which of the following may result from this action?

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

  1. Increased chemical digestion of the protein in the steak by the stomach.

  2. Decreased absorption of the protein in the steak by the small intestines.

  3. An increase in the peristaltic actions of the mans digestive tract.

  4. Increased urine production by the man's kidneys.

Show answer
Correct Option: B
Explanation:
  • Digestion typically begins in the stomach when pepsinogen is converted to pepsin by the action of hydrochloric acid. And continued by trypsin and chymotrypsin in the small intestine. 
  • Before the absorption in the small intestine, most proteins are already reduced to single amino acid or peptides of several amino acids. Hence, he takes several antacid tablets before eating so as to neutralize his stomach acid.
So, the correct answer is 'Decreased absorption of the protein in the steak by the small intestines'.

One of the- following is needed for the conversion of trypsinogen into trypsin  _____________.

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

  1. HCI

  2. Enterokinase

  3. Lipase

  4. Zymase

Show answer
Correct Option: B
Explanation:

In the presence of enterokinase, inactive trypsinogen is converted into active trypsin.

So, the correct answer is 'Enterokinase'

Secretion of gastric juice is stopped by _________.

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

  1. Gastrin

  2. Pancreazymin

  3. Cholecystokinin

  4. Enterogastrone

Show answer
Correct Option: D

Which enzyme initiates protein digestion?

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

  1. Pepsin

  2. Trypsin

  3. Aminopeptidase

  4. Carboxypeptidase

Show answer
Correct Option: A