Tag: bio-chemistry

Questions Related to bio-chemistry

Which one of the following enzyme is absent in invertebrates?

  1. Pepsin

  2. Trypsin

  3. Lipase

  4. Amyalase


Correct Option: B
Explanation:

Protein in invertebrates is a breakdown by four different enzymes known as a proteinase, carboxypolypeptidase, aminopolypeptidase, and dipeptidase, which can be separated by adsorption but vertebrates have one extra enzyme trypsin is also found that helps in activation of the given four and digestion of protein.

So the correct option is 'Trypsin'.

What is common among amylase, rennin and trypsin?

  1. These are produced in stomach

  2. These act at a pH lower than $7$

  3. These all are proteins

  4. These all are proteolytic enzymes


Correct Option: C
Explanation:

Amylase, rennin and trypsin are protein enzymes.

Amylase is enzymes that catalyse the hydrolysis of carbohydrates. Amylase is produced by the pancreas and salivary glands.
Rennin is an enzyme especially produced by stomach for digestion of milk proteins in infants. 
Trypsin is a proteolytic enzyme produced in the small intestine. 
So, the correct option is 'These all are proteins'.

Lipase acts on ________________.

  1. Proteins

  2. Fats

  3. Carbohydrates

  4. Aminoacids


Correct Option: A

The major site of protein breakdown to form free amino acids, is in the

  1. Kidney

  2. Spleen

  3. Intestine

  4. Bone-marrow


Correct Option: C
Explanation:

Pancreatic juice contains pancreatic amylase, lipase and trypsin, trypsin converts polypeptides into the dipeptides in the first part of small intestine i.e., duodenum. The succus entricus in the third part of small intestine i.e., ileum converts dipeptides into the amino acids which are absorbed by the wall of the intestine. Thus, the correct answer is option C.

Proteins are broken down into amino acids completely in

  1. Buccal cavity

  2. Stomach

  3. Intestine

  4. Rectum


Correct Option: C
Explanation:
  • Once a protein source reaches your stomach, hydrochloric acid, and enzymes called proteases to break it down into smaller chains of amino acids. 
  • Amino acids are joined together by peptides, which are broken by proteases.
  • Digestion of protein is completed in the small intestine by the pancreatic enzymes trypsin, chymotrypsin, and carboxypeptidase. Hence, Proteins are broken down into amino acids completely in Intestine. 
So, the correct answer is 'Intestine'.

The three secretions meeting the food in small intestine are

  1. Bile juice, pancreatic juice and intestinal juice

  2. Pancreatic, intestinal and gastric juice

  3. Bile, pancreatic and gastric juice

  4. Bile, gastric juice and saliva


Correct Option: A
Explanation:

Various types of movements are generated by the muscularis layer of the small intestine. These movements help in a thorough mixing up of the food with various secretions in the intestine and thereby facilitate digestion. The bile, pancreatic juice and the intestinal juice are the secretions released into the small intestine. Pancreatic juice and bile are released through the hepato-pancreatic duct. The intestinal mucosal epithelium has goblet cells, which secrete mucus. The secretions of the brush border cells of the mucosa along with the secretions of the goblet cells constitute the intestinal juice or succus entericus.

Digestion of carbohydrates, proteins and fats completes in

  1. Stomach

  2. Liver

  3. Small intestine

  4. Large intestine


Correct Option: C
Explanation:

Small intestine has three parts - duodenum, jejunum and ileum. When food leaves the stomach through its pyloric end and enters the duodenum it is called chyme (acidic). The digestion of macro molecules ingested is completed in small intestine. The digested products are absorbed in the small intestine and comes to the blood.

Maximum digestion of food takes place in

  1. Stomach

  2. Jejunum

  3. Colon

  4. Duodenum


Correct Option: D
Explanation:
  • Small intestine has three parts - duodenum, jejunum, and ileum. 
  • The maximum digestion of food takes place in the duodenum. While the digestion of food is completed in jejunum.
  •  The maximum absorption of food takes place in ileum.

End products of protein hydrolysis are

  1. Mixture of amino acids

  2. Sugars

  3. Peptides

  4. 25 amino acids


Correct Option: A
Explanation:

Proteins are biopolymers made up of  by joining together of amino acids with the help of peptide bonds. When proteins are acted upon by digestive proteolytic enzymes in the gut the peptide bonds are hydrolyzed and a mixture of amino acids is obtained.