DIGESTIVE ENZYMES:

Digestion of carbohydrates:

In oral cavity:

By Saliva:

• Amylase (ptyalin) converts starch & glycogen → Maltose.

In the small intestine:

By Pancreatic juices:

• α — Amylase converts starch → Maltose.

By Intestinal juices:

• Maltase converts maltose →glucose.
• Sucrase converts sucrose → glucose & fructose.
• Lactase converts lactose → glucose & galactose.

Digestion of proteins:

In stomach:

By Gastric juices:

• HCl provides acidic pH.
• Pepsinogen (proenzyme) converted by HCl into Pepsin.

Pepsin converts protein into peptones & proteoses.

• Prorenin (proenzyme) converted by HCl into Renin.

Renin converts Casein (milk protein) into peptides.

In small intestine:

By Pancreatic juices:

Pancreatic juices contain proenzymes.

• Trypsinogen (proenzyme) converted by Enterokinase → Trypsin.

Trypsin converts proteins → Dipeptides.

• Chymotrypsinogen (proenzyme) converted by Trypsin → Chymotrypsin.

Chymotrypsin converts peptones → Dipeptides.

• Procarboxypeptidase (proenzyme) converted by Trypsin → Carboxypeptidase.

Carboxypeptidase converts proteoses → Dipeptides.

• Proelastase (proenzyme) converted by Trypsin → Elastase.

Elastase converts elastin → Dipeptides.

By Intestinal juices:

• Enterokinase is an “enzyme activator”.
• Aminopeptidases convert peptides → amino acids.
• Dipeptidases convert dipeptides → amino acids

MNEMONIC FOR PANCREATIC ENZYMES

• “Eat Tender Chicken Chunks Elegantly”

Enterokinase
Trypsin
Chymotrypsin
Carboxypeptidase
Elastase

Enterokinase is produced by intestinal mucosal cells, while others are produced in the pancreas.

Pancreatic enzymes are secreted by Acinar cells of the pancreas.

Digestion of fats:

In small intestine:

• Bile salts convert fat globules → fat droplets (emulsification).
• Pancreatic lipase converts triglyceride → fatty acids & glycerol.

SUMMARY

Also read:animal physiology MCQ 1

Digestive Enzymes