This handout talks about digestion of lipids, helicobacter pylori, the absorption of digested foods and the structure and function in villus epithelium cells.

1. Digestion of lipids:
 digested by ______ because lipids are _________ in water and melt in the
____________________, forming liquid droplets. Those droplets then
____________ to form larger droplets.
 Lipase is ________________ so it does not enter the lipid droplets. It _________
the lipids on the droplet surface with its ________________________. The
droplets decrease in size, but some cannot be digested completely while the food
is in the alimentary canal.
 ________, a natural detergent from the liver, contains bile salts and breaks up
(emulsifies) the coat lipid droplets, lipids and water into smaller droplets.
Bile is stored in the _________________ and discharged into the
________________ to speed up the emulsification of the lipids and completely
digest them.
Helicobacter Pylori:
o Is an _____________ bacterium => infects stomach lining
o Can cause:
Stomach ulcers Stomach cancer
-> could be caused by excessive -> tumor in the _________
secretion of _______________, but -> reduced _____________________
more likely by H. pylori infection in gastric juice
-> can cause ___________ and then -> higher percentage of infected
ulceration. Its enzymes, including patients
proteases, damage the stomach -> further research needed on link
lining. between H. pylori and cancer
-> _________ treatments cannot relieve
ulcer symptoms permanently.
_______________treatments
eliminate the infection and cure
ulcers
permanently.
-> most severe ulceration: when
infected with strains that produce
toxins causing inflammation
Absorption of digested foods
 By villi of ________ in small intestine
 Tight conjunctions link __________________ of adjacent cells together
 prevent leaking between _________________ (outer layer of cells)

2.  control _________
 _______________ passes through plasma membrane of epithelium cells
 __________, ______, ___________, __________ and _________________
CANNOT be absorbed => egested in feces
Structure and function in villus epithelium cells:
Microvilli  Increase SA of _______________
in ileum => increased absorption
rate by ______________
 Lipids and other foods absorbed by
____________________________.
-> easily pass through
_________________ of plasma
membrane of epithelium cells
 Fructose + hydrophilic food at low
concentration inside body cells
absorbed by __________________.
-> need assistance through
hydrophobic center of plasma
membrane by _________________.
Mitochondria  ____ production -> absorption of
glucose, amino acids, mineral ions
(sodium, calcium + iron) by
________________________ in
plasma membrane of microvilli
Pinocytic vesicles  Formed by ________________
 Contain small droplet of fluid from
___________ of ileum
 Membranes formed from plasma
membrane -> contain
______________ for
___________________ and
_________ for ________________
 Digested food absorbed from them
into ___________