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.
