50 terms

Ch. 24 (Hints and Helps)

carboxypeptidase (what is it? activated by what, released by what?)
Protein digesting enzyme that is activated by trypsin; released as procarboxypeptidase (inactive form)
what is intrinsic factor
a substance produced by the mucosa of the stomach and intestines that is essential for the absorption of vitamin B12
what is hydrolysis?
opposite of dehydration synthesis; breaks apart complex molecules by adding water
what is salivary amylase?
Enzyme in saliva that breaks down starch
what is the pyloric sphincter?
the sphincter muscle of the pylorus that separates the stomach from the duodenum
what is a villus?
A fingerlike projection of the inner surface of the small intestine. Increases the surface area.
what is bile?
A substance produced by the liver that breaks up fat particles. (emulsifies fats into small droplets)
where does most absorption occur?
in the duodenum and the jejunum
where is maltose digested?
digested in the small intestine
pyloric valve sphincter through small intestine
pyloric valve, duodenum, jejunum, ileum, cecum
what is absorbed in the large intestine?
water, ions, and vitamins
stores and secretes bile
where is glucose absorbed and how?
absorbed into the blood stream by the large surface area of blood vessel filled villi.
what is a micelle?
helps to diffuse fats across the brush border, once on the other side, the fats are released
amylase digestion produces?
breaks down starch into glucose molecules (simple sugars/disaccharides)
lipase digestion produces?
an enzyme secreted in the digestive tract that catalyzes the breakdown of fats into individual fatty acids that can be absorbed into the bloodstream
what is aminopeptidase?
enzyme that breaks proteins into amino acids
pepsinogen (secreted by, activated by, becomes ___which_____.)
Secreted inactively by chief cells; activated by HCl to become pepsin, which breaks down proteins into peptides
what cell makes HCl?
parietal cell
what is gastric lipase?
secreted by the chief cells in the stomach, hydrolyzes triglycerides into fatty acids and monoglycerides
what makes gastrin? (and what is it..)
polypeptide hormone secreted by the mucous lining of the stomach
HCl does what?
kills bacteria and denatures proteins
what is trypsinogen?
activated in the duodenum by enterokinase, which is produced in the cells lining the duodenum
RNA digestion?
ribonuclease in pancreatic juice
what activates procarboxypeptidase?
these are used for increasing surface area for absorption in the sm. intestine
lingual lipase digests what, where?
digests lipids in the mouth
gastric lipase aids...
aids the digestion of triglycerides (mainly in milkfat)
what is pancreatic amylase?
enzyme from the pancreas that further breaks down starches into disacharides (maltose, lactose, and sucrose)
what is elastase?
a pancreatic enzyme that breaks down elastin
what is chymotrypsin?
protein splitting enzyme in pancreatic juice
what is sucrase, breaks into?
digestive enzyme that breaks sucrose into glucose and fructose
what is maltase, breaks into?
digestive enzyme that breaks malt sugar into two glucoses
what is lactase, breaks into?
digestive enzyme that breaks lactose into glucose and fructose
dipeptides absorption type
secondary active transport with H+
fructose absorption type
fascilitated diffusion; must be converted to glucose before use
short chain fatty acid absorption type
simple diffusion
pancreatic juice pH
7.1 - 8.2 alkaline
glucose absorption type
secondary active transport with Na+
what are rugae?
folds in the lining of the stomach, help mechanically grind up food
what epithelium is in the GI tract for absorption?
simple columnar epithelium
what are the accessory organs of the digestive system
salivary glands, pancreas, liver, and gallbladder
where are there 3 layers of muscularis
the stomach
bile pH
7.6 - 8.6 alkaline
how are triglycerides transported in the lymph?
tryglycerides are turned into globules along with phospholipids and cholesterol and become coated with proteins, called chylomicrons, which enter the lacteals and transported by way of lymphatic vessels to the thoracic duct and end the blood at the left subclavian vein
what is the major digestion in the stomach?
digestion of starch continues, and digestion of proteins and tryglycerides begins.
what macromolecules are digested by trypsin and chymotrypsin?
what cells make gastrin?
G cells
what is not made by the pancreatic acini
glucagon, insulin, somatostatin, and pancreatic poypeptide.
what cell makes mucous?
exocrine cells