Question

Trypsin differs from pepsin because it digests?
A. Carbohydrates, in alkaline medium in stomach
B. Proteins, in alkaline medium in stomach
C. Protein, in acidic medium of stomach
D. Protein, in alkaline medium in duodenum

Answer 1

Hint: The proenzyme pepsinogen, on exposure to hydrochloric acid, gets converted into an active enzyme called pepsin.
Pepsin is a proteolytic enzyme of the stomach.
The pancreatic juice contains inactive enzyme known as trypsinogen which is activated by enzyme enterokinase into active enzyme trypsin.

Complete answer:
Stomach consists of gastric gland.
Gastric glands have major types of cells as:
1. Mucous neck cells secrete mucus.
2. Peptic or chief cells secrete inactivated proenzyme pepsinogen.
In the stomach, the proenzyme pepsinogen in the presence of hydrochloric acid gets converted into an active enzyme called pepsin.
Pepsin is a proteolytic enzyme of the stomach.
Pepsin converts into proteoses and peptides.
Pancreatic juices are released through hepato-pancreatic duct.
Pancreatic juice contain inactive enzyme such as:
1. Trypsinogen
2. Chymotrypsinogen
3. Procarboxypeptidase
4. Amylases
5. Lipases
6. Nucleases
The pancreatic juice contains inactive enzyme known as trypsinogen which is activated by enzyme enterokinase into active enzyme trypsin.
Both pepsin and trypsin are proteolytic enzymes.
Pepsin is secreted in the stomach and trypsin is a component of pancreatic juice.
Pepsinogen is activated to pepsin in the stomach in the presence of hydrochloric acid.
The pH for activity of pepsin is 1.8.
Pepsin is a strong end peptidase and breaks proteins into smaller molecules like peptones, proteoses and peptides.
Trypsinogen is converted into trypsin by the action of enterokinase.
Enterokinase is secreted by the duodenal mucosa.
Trypsin and chymotrypsin are end peptidase type of enzymes and are active in alkaline pH i.e., 7.5 to 8.
They dissociate proteins into peptones and proteoses.

So, the correct option is D. Protein, in the alkaline medium in duodenum.

Note: The activities of gastrointestinal tract are under neural and hormonal; control for proper coordination for different parts.
The sight, smell and presence of food in the oral cavity can stimulate the secretion of saliva.
Gastrin stimulates the secretion of gastric juices and intestinal secretions are also.