Tag: bio-chemistry

Questions Related to bio-chemistry

Protein digesting enzyme is

  1. Pepsin

  2. Ptyalin

  3. Amylase

  4. Maltase

  5. Sucrase


Correct Option: A
Explanation:
  1. Pepsin is produced in the stomach and is one of the main digestive enzymes, which helps in digestion of the proteins in food. Zymogenic cell or peptic cell is a cell in the stomach that releases pepsinogen and chymosin.
  2.  The inactive pepsinogen, on exposure to hydrochloric acid, gets converted to the active enzyme pepsin, the proteolytic enzyme of the stomach. Pepsin converts proteins into proteoses and peptones (peptides). 
  3. Pepsin hydrolyses proteins to polypeptide chains and initiates protein digestion  Hence, the protein-digesting enzyme is pepsin.
So, the correct answer is 'pepsin'.

I. Amylase
II. Lipase
III. Pepsin
IV. Trypsin

Out of the aforementioned enzymes, the protein-digesting enzymes are

  1. I and II.

  2. I and III.

  3. II and III.

  4. II and IV.

  5. III and IV.


Correct Option: E
Explanation:

Protein digestive enzymes are pepsin and trypsin. They break down proteins into smaller peptides and amino acids. Pepsin is secreted by the gastric gland in the stomach where as trypsin is secreted by Pancreas.

Amylase and Lipase are other important digestive enzymes as well and they help in digestion of starch and fats respectively. Hence option E is correct.

Which of the following is true about digestion and absorption of food?

  1. Trypsin, chymotrypsin and carboxypeptidase are brush border enymes

  2. The chemical process of digestion is initiated in the oral cavity. A bout $60\%$ starch is hydrolysed here by salivary amylase to form maltose

  3. Rennin is proteolytic enzyme found in grastic juice of infants. Small amounts of lipases are also secreted by the gastric glands

  4. If breast feeding is replaced by less nutritive food low in proteins and calories, the infants below the age of one year will suffer from kwashiorkar


Correct Option: C
Explanation:
Rennin is a proteolytic enzyme present in the gastric secretion of infants that allows digestion of milk products. Small amounts of Gastric Lipase is also secreted by the gastric glands.
So, the correct option is 'Rennin is proteolytic enzyme found in grastic juice of infants. Small amounts of lipases are also secreted by the gastric glands'.

What is the important role of water in the process of digestion :-

  1. Prevent dehydration

  2. Metabolic process

  3. $1st$ and $2nd $ both

  4. Provides energy


Correct Option: A

Which of the following helps in the digestion of food?

  1. Hormones

  2. Digestive juice

  3. Water

  4. Blood


Correct Option: B
Explanation:

  • The process of digestion begins from the mouth itself and gets completed in small intestine.
  • Stomach plays a key role in the digestion of food. It has gastric glands which secrete gastric juices needed to break down food to simple nutrients and thereby contributing to digestion.
  • There are different hormones in our body that has different functions. For example, there could be pH changes associated with different types of food. This pH change stimulates the secretion of a hormone called gastrin which induces the production of digestive juices. But it is not directly connected to the digestion process.
  • Water is present in cell, organs and tissues to help regulating temperature and maintaining body functions.
  • Absorbed food enters the blood stream and is taken to different parts of the body.
So, the correct option is B.

Who revealed secrets of digestion?

  1. Mendel

  2. Beaumont

  3. Newton

  4. S. Bose


Correct Option: B
Explanation:
  • William Beaumont revealed the functioning of human stomach in a living person. In 1833, He published his findings in the book, 'The Experiments and Observation of the Gastric juice and Physiology of Digestion'. After 10 years from there, he listed many conclusions about the chemical nature of digestion.
  • He primarily discovered that gastric juice is responsible for the breakdown of food into simple nutrients and he also described the movement of stomach during digestion. 
  • So, the correct option is B.

Digestion is completed in

  1. Duodenum

  2. Ileum

  3. Stomach

  4. Cloaca


Correct Option: B
Explanation:

Digestion is completed in the Ileum because it is the last part of small intestine where all the digestive secretions end. From the large intestine, the process of absorption occurs predominantly.

So, the correct option is B.

Enterokinase / enteropeptidase takes part in conversion of

  1. Pepsinogen to pepsin

  2. Trypsinogen to trypsin

  3. Protein into polypeptides

  4. Caseinogen into casein


Correct Option: B

Epithelial cells involved in absorption of digested food have on their free surface

  1. Zymogen granules

  2. Pinocytic vesicles

  3. Phagocytic vesicles

  4. Microvilli


Correct Option: D