Digestive Systems (Part 3) Flashcards
What are the 5 major steps in digestion?
- feeding
- mastication
- use of enzymes
- transport
- excretion
What is feeding?
acquisition of food
What is mastication?
mechanical digestion
What are enzymes used for?
chemical digestion
What does transport mean in digestion?
absorption of nutrients
What is excretion?
removal of indigestible waste
What is salivary amylase produced by?
salivary glands
What does salivary amylase do?
breakdown polysaccharides (starch) in the mouth into disaccharides (maltose) and oligosaccharides
What is pancreatic amylase produces by?
pancrease
What does pancreatic amylase do?
break down polysaccharides (starch) in the small intestine into disaccharides (maltose) and monosaccharides
What is oligosaccharidases produced by?
lining of intestine; brush border membrane
What do oligosaccharidases do?
break down disaccharides in the small intestine into monosaccharides
Where is pepsin produced by?
stomach (chief cells)
What does pepsin do?
break down polypeptides (protein) in the stomach into smallpeptides
Where is trypsin produced?
pancreas
What does trypsin do?
break down polypeptides (proteins) in the duodenum into small peptides
What does elastase do?
break down proteins in the small intestine into peptides
Where is elastase made?
pancrease
What is chymotrypsin produced by?
pancreas
What does chymotrypsin do?
break down polypeptides (proteins) in the duodenum into small peptides
What is carboxypeptidase produced by?
pancreas
What does carboxypeptidase do?
break down peptides in the duodenum into amino acids
What is aminopeptidase produced by?
small insteine
What does aminopeptidase do?
break down peptides in the small intestine into amino acids
What is dipeptidase produced by?
lining of intestine
What does dipeptidase do?
break down peptides in the small intestine into amino acids
Where does the process of carbohydrate digestion usually begin?
in the mouth
What enzyme does digestion in the mouth?
salivary amylase
Where is carbohydrate digestion completed
in the duodenum
Where are carbohydrates absorbed?
absorption of monosaccharides in the small intestine
Where does carbohydrate digestion not occur? Why?
esophagus or stomach; low pH
Where does protein digestion begin?
stomach
How does protein digestion occur in the stomach?
pepsinogen converted into pepsin
Where is protein digestion completed?
small intestine
Where does protein absorption occur?
small intestine
describe carbohydrate absorption?
carbohydrate broken down into monosaccharides. transport protein carries across intestinal epithelium and another transport protein carries across into blood capillary
describe protein absorption?
protein broken down into amino acids in the lumen of small intestine (?). transport protein carries across intestinal epithelium into epithelial cell of intestinal villus. Transport protein then carries into blood capillary
Where does lipid digestion begin?
stomach
What digests lipids in the stomach?
gastric lipase
Is stomach digestion of lipids major or minor?
minor
Where are lipids emulsidied?
duodenum
What emulsifies lipids?
bile
What does pancreatic lipase turn lipids into?
fatty acids and glycerides
Where are lipids absorped?
into small intestine
How does lipid absorption occur?
- reassembly into triglycerides
- formation of chylomicrons
- transport into lymphatic system
How are amino acids and monosaccharides absorpted?
transported through epithelial cells to blood
Where does blood carry amino acids and monosaccharides?
to liver
How does blood carry amino acids and monosaccharides?
via hepatic portal vein
How are fatty acids and monoglycerides absorbed?
diffuse into epithelial cells
What happens after fatty acids and monoglycerides get into epithelial cells?
reassembled into chylomicrons
How are chylomicrons transported?
via lymphatic system
What are chylomicrons?
sphere of troglycerides
