Pancreatic enzymes of the GI Tract

Enterokinase

FUNCTION: An activating brush border enzyme which splits off part of the trypsinogen molecule to form trypsin

Trypsinogen

FUNCTION: Inactive form of trypsin, turned on by enterokinase.

Trypsin Inhibitor

FUNCTION: Protein that combines with any trypsin formed accidentally in the pancreas or pancreatic juice, and blocks its enzymatic ability.

Chymotrypsinogen, Procarboxpeptidase, Proelastase

FUNCTION: Trypsin acts on these inactive precursors to produce chymotrypsin, carboxypeptidase and elasstase, respectively.

Salivary Amylase

PRODUCED / SECRETED BY: Parotid, sublingual and submandibular salivary glands. SUBSTRATE: Carbohydrates (polysaccharides) PRODUCT: Maltose ( disaccharide), maltotriose (trisaccharide), . . . simple sugars

Chymosin (Rennin)

PRODUCED / SECRETED BY: Produced by Chief cells in the stomach during infancy. SUBSTRATE: Milk PRODUCT: Curds (calcium paracaseinate) and Whey (liquid part of curdled milk).

Gastric Lipase

PRODUCED / SECRETED BY: Produced by Chief cells in the stomach during infancy. SUBSTRATE: Triglycerides (fats and oils) that have been emulsified by bile salts. PRODUCT: Fatty acids and monoglycerides.

Pepsinogen

PRODUCED / SECRETED BY: Produced by Chief cells in the stomach. SUBSTRATE: Proteins PRODUCT: Short chain polypeptides

Small Intestine Brush Border Enzymes

PRODUCED / SECRETED BY: Produced by Microvilli SUBSTRATE: Peptides and Dipeptides, Maltose and Nucleotides PRODUCT: Amino acids, glucose and Nitrogen bases (A, U, G, C, T), pentose and phosphate.

Lingual Lipase

PRODUCED / SECRETED BY: Produced by cells on dorsum of tongue. SUBSTRATE: Triglycerides (fats and oils) PRODUCT: Fatty acids and monoglycerides.

Trypsin

PRODUCED / SECRETED BY: Produced in pancreatic acinar cells carried in pancreatic juices, acts in the small intestine. SUBSTRATE: Proteins PRODUCT: Short chain peptides (10 - 100 amino acid chain.

Ribonuclease

PRODUCED / SECRETED BY: Produced in pancreatic acinar cells carried in pancreatic juices, acts in the small intestine. SUBSTRATE: Ribonucleic acid PRODUCT: Nucleotides (Adenine, Uracil, Guanine, Cytosine + phosphate groups and ribose sugar)

Pancreatic amylase

PRODUCED / SECRETED BY: Produced in pancreatic acinar cells, carried in pancreatic juices, acts in the small intestine. SUBSTRATE: Carbohydrates (Polysaccharides) PRODUCT: Maltose (disaccharide), maltotriose (trisaccharide). . . simple sugars.

Deoxyribonuclease

PRODUCED / SECRETED BY: Produced in pancreatic acinar cells, carried in pancreatic juices, acts in the small intestine. SUBSTRATE: Deoxyribonucleic acid PRODUCT: Nucleotides (Adenine, Thymine, Guanine, Cytosine + phosphate groups and deoxyribose sugar)

Chymotrypsin

PRODUCED / SECRETED BY: Produced in pancreatic acinar cells, carried in pancreatic juices, acts in the small intestine. SUBSTRATE: Proteins PRODUCT: Short chain peptides

Elastase

PRODUCED / SECRETED BY: Produced in pancreatic acinar cells, carried in pancreatic juices, acts in the small intestine. SUBSTRATE: Proteins PRODUCT: Short chain peptides

Carboxypeptidase

PRODUCED / SECRETED BY: Produced in pancreatic acinar cells, carried in pancreatic juices, acts in the small intestine. SUBSTRATE: Proteins (breaks the peptide bond that attaches the terminal amino acid to the carboxyl end of the peptide. PRODUCT: Short chain Peptides and amino acids.

Pancreatic Lipase

PRODUCED / SECRETED BY: Produced in pancreatic acinar cells, carried in pancreatic juices, acts in the small intestine. SUBSTRATE: Triglycerides (fats and oils) that have been emulsified by bile salts. PRODUCT: Fatty acids and monoglycerides.