BIBC 120 Lecture Notes - Lecture 14: Cholesteryl Ester, Portal Vein, Pancreatic Lipase Family
24 May 2018
School
Department
Course
Professor
Week 5.2
- cis[position of double bond]-[# of C’s]:[# of Usat. ods]
o Failies of polyusaturated fatty aids are also desigated y the oega ω aig
system- positio of the first aro otaiig a doule od outig fro the ω-end
(methyl)
o
o Fatty acids in animals and plants are stored as triglycerides (glycerol backbone with 3
FA’s. All fats and oils are triglycerides.
o Digestion of fats requires hydrolysis of the fatty acids from the glycerol
backbone. This is accomplished by lipase enzymes.
o Sterol
o Cholesterol (with hydroxyl group and methyl chain)
o cholesteryl ester (ester linkage COO- to fatty acid)
DIGESTION OF FATS
Hydrolysis of free fatty acids from triglycerides by lipases (enzymes that catalyze hydrolytic
reaction on lipids)
- Problem: fat/oil is hydrophobic, consumed as fat globules not in solution
- Mouth: hydrolysis of some fatty acids in the mouth (lingual lipase) need to know specific
names
- Stomach: Gastric churning helps to break up large fat globules, Gastric lipase produce by
chief cells in gastric pits, Digestion through this point is relatively minor
- Small Intestine: emulsification by bile then enzymatic digestion by pancreatic lipase
breakdown remaining triglycerides in the ingested fat. → micelles of monoglycerides,
free FA, some free glycerol (after small intestine?)
o Emulsification - breaking large fat globules into tiny droplets called micelles.
(micelles are amphipathic molecules – polar charged part on outside,
hydrophobic part inside)
o Bile –produced in liver, stored in gall bladder, released into the duodenum of the
small intestine
▪ emulsifying agents in bile are: Bile acids, Phospholipids, Cholesterol (to a
much lesser extent)
▪ Bile acids (charged) are synthesized in the liver from cholesterol
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
All fats and oils are triglycerides: digestion of fats requires hydrolysis of the fatty acids from the glycerol backbone. This is accomplished by lipase enzymes: sterol, cholesterol (with hydroxyl group and methyl chain, cholesteryl ester (ester linkage coo- to fatty acid) Hydrolysis of free fatty acids from triglycerides by lipases (enzymes that catalyze hydrolytic reaction on lipids) Problem: fat/oil is hydrophobic, consumed as fat globules not in solution. Mouth: hydrolysis of some fatty acids in the mouth (lingual lipase) need to know specific names. Stomach: gastric churning helps to break up large fat globules, gastric lipase produce by chief cells in gastric pits, digestion through this point is relatively minor. Small intestine: emulsification by bile then enzymatic digestion by pancreatic lipase breakdown remaining triglycerides in the ingested fat. Dietary short chain fa (10c or less) have some solubility in solution.
