Term
| What are the sources of fatty acids? |
|
Definition
1. dietary
2. de novo synthesis
3. adipose |
|
|
Term
1. What is at the center of lipid metabolism?
2. What is it produced from? |
|
Definition
1. Acetyl CoA
2. amino acids, ketones, fatty acids, glucose |
|
|
Term
| Acetyl CoA is a precursor of _______, which can be converted to ________ and _______. |
|
Definition
1. cholesterol
2. steriod hormones
3. bile salts |
|
|
Term
| Acetyl CoA can be coverted to fatty acids, which in turn can make 4 things.... |
|
Definition
| phospholipids, TAGS, ketone bodies, eicosanoids |
|
|
Term
| Dietary fat consists mainly of? |
|
Definition
TAGS! (90%)
cholesterol esters
phospholipids |
|
|
Term
| List the 4 bile functions. |
|
Definition
1. emulsify TAGS for digestion
2. solubilizes cholesterol in gallbladder
3. excretes cholesterol
4. helps absorption of fat-soluble vitamins |
|
|
Term
Which three enzymes degrade emulsified lipids?
|
|
Definition
1. phospholipase A2 2. pancreatic lipase 3. cholesterol esterase
|
|
|
Term
1. Where does pancreatic lipase cleave?
2. What products are formed?
3. What does it require? |
|
Definition
1. f/a on 1 and 3 sequentially
2. 1,2 diacylglycerol and 2-monoacylglycerol
3. colipase |
|
|
Term
1. Where is phospholipase A2 made?
2. secreted?
3. active or inactive form? |
|
Definition
1. pancreas
2. intestine
3. inactive (requires trypsin) |
|
|
Term
Rx of phospholipase A2?
Products formed? |
|
Definition
Cleaves ester linkage between fatty acid and hydroxl at C2 of phospholipid
free fatty acid and lysophospholipid |
|
|
Term
| What is the importance of lysophospholipid? |
|
Definition
| helps emulsify other lipids |
|
|
Term
What are other sources of phospholipase A2?
What is the clinical importance of this? |
|
Definition
bee and snake venom
mammalian tissue and pancreatic juice
makes lysophospholipid which cleaves membranes of RBCs |
|
|
Term
| Phospholipase A2 acts on phosphatidylinosital to release? |
|
Definition
| arachidonic acid which is a precursor of leukotriene and prostaglandins |
|
|
Term
| Which is phospholipase A2 inhibited by? |
|
Definition
|
|
Term
Where are these found?
Phospholipases..
1. A1
2. C
3. D |
|
Definition
1. mammalian tissue
2. liver lysosomes, bacilli
3. plants
remember C, is important in 2nd mes. |
|
|
Term
|
Definition
| triacylglycerol → 1,2 diacylglycerol + fatty acid → 2 monoacyglyerol |
|
|
Term
|
Definition
| phospholipid → fatty acid + lysophospholipid |
|
|
Term
|
Definition
| cholesterol esterase → cholesterol |
|
|
Term
Acetyl-CoA: cholesterol acyl transferase
(ACAT) |
|
Definition
cholesterol + acyl CoA → cholesteryl ester + CoA
(lipid droplet in cell) |
|
|
Term
| lecithin: cholesterol acyltransferase (LCAT) |
|
Definition
phosphatidylcholine + cholesterol → cholesteryl ester +lysophosphatidylcholine
storage in blood as lipoprotein |
|
|
Term
|
Definition
TAGS → fatty acids + glycerol
f/a forms complex with serum albumin |
|
|
Term
| What determines whether lipids in the chylomicrons will be taken up by that cell? |
|
Definition
| lipoprotein lipase in vasculature |
|
|
Term
| VLDL is converted to IDL by gaining more ____ from ____. |
|
Definition
| cholesteryl esters from HDL |
|
|
Term
Familial hypercholesterolemia show mutations in ______.
risks include? |
|
Definition
LDL receptor
atherosclerosis |
|
|
Term
| Describe the mechanism by which glucagon stimulates lipolysis. |
|
Definition
| Beta adergenic receptor- cAMP dependent protein kinase phosphorylates hormone sensitive triacylglyerol lipase (activating it). |
|
|
Term
| Generalized bile synthesis in the liver: |
|
Definition
cholesterol is converted to bile via 7α-hydroxylase.
*down regulated by high bile
*rate limiting step |
|
|
Term
|
Definition
Bile duct carries bile salts from liver to intestines
Portal vein carries bile salts and acids to liver. |
|
|
Term
| What would you see in a person with a bile duct obstruction? |
|
Definition
1. jaundice (buildup of bilirubin in blood)
2. steatorrhea (>6g/day fecal fat)
* salts in portal blood cause inc. secretion of bile salts, inhibits de novo syn of bile |
|
|
Term
|
Definition
| imbalance between bile and cholesterol |
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