Chapter 4: Digestion & Absorption Flashcards
what enzyme is in mouth
amylase
what is epiglottis
flap in esophagus
pH of stomach
2 (acidic)
parietal cells
excrete HCl
Chief cells
release pepsinogen and gastric lipase
where are parietal and chief cells found
gastric pits
HCl purpose
kills bacteria, starts unfolding proteins
where is most absorption
small intestine (duodenum)
how is surface area increased
-circular folds: slows chyme, mixes
-villi
types of villi cells
-enterocytes (absorb nutrients)
-goblet (secrete mucus)
-endocrine (secrete hormones)
what are glycocalyx
sugars that come off microvilli, full of enzymes
large intestine function
-absorb water/electrolytes
-microbiome
microbiome function
synthesize vit K, biotin (B7), and short chain fatty acids
probiotics
microorganisms in food
prebiotics
indigestible, used by bacteria
pancreas function
-5-6 cups juices
-produce sodium bicarbonate
-produce digestive enzymes
liver function
-2-4 cups a day
-produce bile
gallbladder function
-stores bile
what types of enzymes does pancreas make
-amylase (carbs)
-lipase (lipids)
-trypsin (protein)
-chymotrypsin (protein)
layers of GI tract (in to out)
-mucosa layer
-circular longitudinal muscles (mixes, propels)
-serosa (secretes water, smooth padding)
how GI moves
-segmentation (mixes food, breaks up)
-peristalsis (moves food)
places that have emzymes
-mouth (salivary)
-stomach
-pancreas
-small intestine
hydrolysis
add water -> breaks molecules
active transport
requires ATP, against the grain
passive diffusion
small hydrophobic no issue
facilitated diffusion
channel needed to pass through the membrane (along grain)
endocytosis
transport by vesicle O
endopeptidase
cuts up proteins into chunks but cannot do individual
how is pepsinogen activated
when pepsin cuts off the 44 AA chain and it becomes pepsin
enterohepatic circulation
95% bile salts being returned to liver
purpose of bile salts
emulsification in small intestine
what are bile salts made of
cholesterol + hydrophilic part (amino acid)
cardiovascular vs lymphatic absorbs…
lymphatic: fats, fat soluble vits
cardiovascular: everything else
how does lymphatic system work
moves through valves since no pump, to thoracic duct where they enter the blood
how does cardiovascular system work
nutrients taken to liver where some stored and metabolized, and some returned to body
GERD what is it
stomach acid in esophagus
GERD causes
-hiatal hernia
-alc
-smocking
-obesity
-pregnancy
GERD treatments
eat calcium carbonate (tums/chalk)
what is inside the stomach
-gastric juices
-acid
-pepsin enzyme
what does the pancreas secrete
pancreatic juice containing…
-digestive enzymes
-bicarbonate
enzymes in the body
-mouth: amylase
-stomach: pepsin, lipase, IF
-pancreas->small intestine: amylase, lipase, trypsin, chymotrypsin
which is active form pepsin or pepsinogen
pepsin
how is pepsinogen activated
the HCl activates it by turning it into pepsin (by removing the 44 AA)
what is the purpose of pepsin
to break down the proteins into smaller chains
types of endopeptidase
-pepsin
-trypsin
-chymotrypsin
