Examples of digestive exoenzymes Exoenzyme

1 examples of digestive exoenzymes

1.1 amylases
1.2 lipoprotein lipase
1.3 pectinase
1.4 pepsin
1.5 trypsin

examples of digestive exoenzymes
amylases

pancreatic alpha-amylase 1hny

amylases group of extracellular enzymes (glycoside hydrolases) catalyze hydrolysis of starch maltose. these enzymes grouped 3 classes based on amino acid sequences, mechanism of reaction, method of catalysis , structure. different classes of amylases α-amylases, β-amylases, , glucoamylases. α-amylases hydrolyze starch randomly cleaving 1,4-a-d-glucosidic linkages between glucose units, β-amylases cleave non-reducing chain ends of components of starch such amylose, , glucoamylases hydrolyze glucose molecules ends of amylose , amylopectin. amylases critically important extracellular enzymes , found in plants, animals , micro-organisms. in humans, amylases secreted both pancreas , salivary glands both sources of enzyme required complete starch hydrolysis.

lipoprotein lipase

lipoprotein lipase (lpl) type of digestive enzyme helps regulate uptake of triacylglycerols chylomicrons , other low-density lipoproteins fatty tissues in body. exoenzymatic function allows break down triacylglycerol 2 free fatty acids , 1 molecule of monoacylglycerol. lpl can found in endothelial cells in fatty tissues, such adipose, cardiac, , muscle. lipoprotein lipase downregulated high levels of insulin, , upregulated high levels of glucagon , adrenaline.

pectinase

pectinases, called pectolytic enzymes, class of exoenzymes involved in breakdown of pectic substances, notably pectin. pectinases can classified 2 different groups based on action against galacturonan backbone of pectin: de-esterifying , depolymerizing. these exoenzymes can found in both plants , microbial organisms including fungi , bacteria. pectinases used break down pectic elements found in plants , plant-derived products.

pepsin

discovered in 1836, pepsin 1 of first enzymes classified exoenzyme. enzyme first made in inactive form, pepsinogen chief cells in lining of stomach. impulse vagus nerve, pepsinogen secreted stomach, mixes hydrochloric acid form pepsin. once active, pepsin works break down proteins in foods such dairy, meat, , eggs. pepsin works best @ ph of gastric acid, 1.5 2.5, , deactivated when acid neutralized ph of 7.

trypsin

also 1 of first exoenzymes discovered, trypsin named in 1876, forty years after pepsin. enzyme responsible breakdown of large globular proteins , activity specific cleaving c-terminal sides of arginine , lysine amino acid residues. derivative of trypsinogen, inactive precursor produced in pancreas. when secreted small intestine, mixes enterokinase form active trypsin. due role in small intestine, trypsin works @ optimal ph of 8.0.