DIGESTIVE FUNCTIONS OF PANCREATIC JUICE

 

INTRODUCTION: The secretion of pancreatic juice aids digestion in several ways. The large amount of bicarbonate in the juice helps to neutralize the acidic chyme from the stomach so that the pancreatic enzymes can function optimally in a neutral pH range. Each enzyme also has an important digestive function.

CARBOHYDRATE DIGESTION: In digesting carbohydrates, pancreatic amylase splits straight-chain glucose polysaccharides also known as amyloses in starch, into smaller α-limit dextrins: maltose and maltotriose. Brush border enzymes in the small intestine complete the hydrolysis of these smaller sugars into glucose, which is transported across the intestinal epithelium by Na⁺-coupled transport.

FAT METABOLISM: Pancreatic lipase contributes to fat metabolism by hydrolyzing triglycerides into fatty acids and a monoglyceride; this activity is most efficient in the presence of bile acids, which serve to emulsify the triglycerides. Phospholipase A2 splits a fatty acid off from lecithin to form lysolecithin.

NUCLEIC ACID METABOLISM: Ribonuclease and deoxyribonuclease attack the nucleic acids.  The remaining enzymes help digest proteins. Trypsin, chymotrypsin, and elastase are endopeptidases that is to say, they cleave peptide bonds in the middle of polypeptide chains. Carboxypeptidase is an exopeptidase that is, it splits peptide bonds adjacent to the carboxyl terminals of peptide chains. Together, these proteases break down proteins into oligopeptides and free amino acids.

RELATED;

1.  THE ENDOCRINE PANCREAS

2.  INFLAMMATION OF THE PANCREAS

3.  ANATOMY AND PHYSIOLOGY

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