s437 Small Intestine Digestion Flores

Pancreatic amylase

Splits polysaccharide into disaccarides

Pancreatic lipase

Fat-digesting enzyme; breaks down triglycerides into fatty acids and monoglycerides

Pancreatic proteases

chymotrypsin and carboxypeptidase

Trypsin

released as inactive tyrpsinogen, which is activated by enterokinase, activates chymotryposin and carboxypeptidase

Chymotryposin

Digest proteins- released as inactive... activated by trypsin

Carboxypeptidase

Digest proteins- released as inactive procarboxypeptidase... activated by trypsin

Nucleases

Digest nucleic acids

Bicarbonate ions

Make pancreatic juice alkaline; neutralize the acid in chyme

Trypsinogen

Released inactive, activated by enterokinase

Brush border

Surface of a cell covered with microvilli. increases surface area of a cell for absorption

Brush border enzymes

Located in small intestine. Carry out final stages of enzymatic digestion. Maltase, Lactase, Sucrase, Lipase, Protease, nuclease

Maltase

breaks down the disaccharide maltose

Lactase

breaks down the disaccharide lactase

Sucrase

breaks down the disaccharide sucrose

parts of the small intestine

duodenum, jejunum, and the ileum

duodenum

The first part of the small intestine

zymogen

A protein that is an inactive precursor of an enzyme

Catalase

Enzyme found in the liver, breaks down hydrogen peroxide into water and oxygen

pH of pancreatic juice

8

CCK

Stimulated by fat and proteins in the small intestine, increases pancreatic enzymes, and stimulates the release of bile by contracting the gall bladder

Secretin

A hormone secreted by the small intestine (duodenum) in response to low pH (e.g., from stomach acid). It promotes the release of bicarbonate from the pancreas to act as a buffer.

hepatopancreatic sphincter

the muscle that controls the emptying of bile and pancreatic juices into the duodenum; may also be referred to as the sphincter of Oddi

villi

Fingerlike extensions of the intestinal mucosa that increase the surface area for absorption

Microvilli

Fingerlike extensions of plasma membrane of apical epithelial cells, increase surface area, aid in absorbtion, exist on every moist epithelia, but most dense in small intestine and kidney