Choose all the true statements about protein digestion and hydrolysis.

A. The chemical digestion of proteins begins in the mouth with the process of mastication.

B. In the small intestine, carboxypeptidase attacks peptide bonds.

C. Free amino acids are passively absorbed through the intestinal wall.

D. Pancreatic juices are more acidic than gastric juices.

E. Pepsin causes the hydrolysis of some of the peptide bonds in proteins.

B. In the small intestine, carboxypeptidase attacks peptide bonds.

E. Pepsin causes the hydrolysis of some of the peptide bonds in proteins.

Explanation:

The digestion of protiens doesn't occur in mouth, it occurs at only 2 locations in GIT:

In the stomach In the small intestine

Digestion of protiens start in stomach causing the stimulation of gatrin hormoone which stimulates the release of gastric juice containing HCl, Pepsinogen, Rennin (in infants). The pepsinogen is activated to pepsin by HCL and pepsin itslef, and cause hydrolysis of the peptide bonds in the protiens.

The remainder of protien digestion occurs in small intestine as a result of the action of enzymes including trypsin and peptidases. Carboxypeptidases attack the peptide bonds and result in cleavage.

A, B, C and E

Explanation:

A. The moment food mixes with saliva in the mouth when chewing, chemical digestion starts, because saliva contains enzymes that breaks down carbohydrates.

C. Free amino acids can either take passive or active transport system, thus it can be absorbed through intestinal wall.

E. Pepsin acts as a catalyst to the hydrolysis of the peptide bond. The reaction enables the process of digestion by breaking down the protein into smaller pieces.

B. Carboxyperptidase attacks or cleave the peptide bonds, also Trypsin do attacks or cleave the peptide bonds.

However,

D. Pancreatic Juice are more alkaline in nature, while gastric juice are more acidic in nature.