biochem lesson 35.txt
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biochem lesson 35.txt
What are the basic building blocks of life?
How many fatty acids can triacylglycerol
What are the five lipids?
“Feed the pig stale greens”
1) Fatty Acids
What percentage of calories should be from fat?
What percentage of the dietary lipids should be essential
Where can you find omega-6 and omega-3 F.A.s?
6 = plant oils
3 = fish oils
Name the stages of digestion and absorption?
3) pancreatic enzymes for SI release
4) small intestine
5) enterocyte absorption
6) resynthesis of lipids in enterocytes
7) sent out to tissues via chylomicrons
Name the steps of hormone mediation during lipid
1) Lipid to stomach
2) CCK released
- slow down absorption
- allow pancreatic enzymes to be released
- allow bile salts to be released
- satiety b/c of CNS
3) Secretin released b/c of low pH from stomach
- stimulates bicarb release from pancreas
What is the function fo a lipase?
Chemical to catalyze hydrolysis of FA from lipids
Which TAG does not require bile salts?
Short and Medium if less than 20 carbons
What are the two structures formed from Bile Salts?
2) Mixed Micelles
What do emulsion droplets do?
prevent coalescence of lipid
allow for digestion
How does Pancreatic Lipase function?
1) Colipase anchors pancreatic lipase to
2) PL functions as long as pH is below 7.0
3) PL removes 2 FAs
4) TAG to 2-MAGs
***without bile salts to emulsify and colipase to
anchor, pancreatic lipase could not function
What are the four products generated from lipases?
2) Vitamen ADEK
3) 2- MAG
What are the two chemicals that can be used to compete with Cholesterol for entrance into mixed micelles?
Do long chain FA require carrier proteins to cross membrane?
What is the fucntion of Ezetimibe (zetia)?
block membrane carrier for absorption to lower serum cholesterol
What causes lipid malabsorption?
Bile sale deficiency
pancreatic enzyme deficiency
What drug would you give a person who lacks pancreatic eznymes?
What drug is prescribed to keep fat in the stools so a person can lose weight?
Orlistat (can cause steatorrhea)
How are TAGs resynthesized in the enterocytes by 2-MAGs?
1) long-chain FA activated by fatty acyl CoA synthetase (thiokinase)
2) TAG Synthase
: Catalyzes synthesis of TAG from 2-MAGs and 2 fatty acyl CoA
3) TAG sent to Chylomicron for shipping
How is the cholesterol ester formed?
1) Fatty acyl CoA Synthase (thiokinase) converts long-chain FA to fatty acyl CoA
2) One FA CoA reacts with cholesterol to form cholesterol ester
What are the main constituents of chylomicrons?
Lipoprotein = chylomicron
1) monolayer of phospholipids and unesterified cholesterol
2) Cholesterol esters
How long should you fast before giving blood to test lipid levels?
Process of Chylomicron release?
- released to lacteals via calcium-mediated exocytosis
- travel in lymphatics
- enter blood
How does Lipoprotein lipase function on chylomicrons?
1) LL in glycocalyx binds CM
2) hyrolyses CM if there is apcCII on the CM membrane
3) FA released for fuel in muscles and storage in adipose
4) Glycerol sent to Liver
5) remaining CM sent to Liver with contents of cholesterol, remaining TAG, fat-soluble vitamins
Insulin and TAG synthesis (Lipogenesis)
1) Insulin mediates storage in adipose
2) insulin regulates lipoprotein lipase directly (higher insulin = higher LL)
3) insulin stimulates GLUT-4
What is the function of Gemfibrozil?
Increase degradation of TAGs and uptake of FAs
great to treat hypertriacylglycerolemias
What is released from TAG upon contact with Lipoprotein lipase?
3 fatty acids