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24 Cards in this Set
- Front
- Back
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1. What are the major saturated FA in mammalian cells?
Which FA are rarely found in mammalian cells? What are the major unsaturated FA in animal and plant tissue? |
Palmitic Acid
Stearic Acid Short-chain FA Oleic Acid Palmitoleic Acid |
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2. What are the three essential polyunsaturated FA?
What can deficiencies in these cause? What is meant by 18:2∆⁶⁸? |
1. Linoelic Acid
2. Linolenic Acid 3. Arachidonic Acid Skin/kidney damage, cataracts, increase membrane permeability 18 C's 2 double bonds Occur as carbon 6 and 8 |
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3. How are double bonds in most naturally occurring unsaturated FA?
How are trans-FA created? What do trans-FA act like? What do trans-FA do? |
Cis double bonds
Produced by hydrogenation (solidify liquid vegetable oil) Act like saturated FA more than cis FA Affect the physical structures of membranes (rigid memebrane) Also increase LDL, TG, and platelet aggregations |
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4. What are fish oils rich in?
What does this do? What type of bonds do poly and mono unsaturated FA have? |
ω-3 polyunsaturated FA
Decreases cardiovascular mortality Cis double bonds |
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5. What are acylgylcerols?
What do they contain? In humans, how are long-chain FA mainly stored? |
Monoacylglycerols, diacylglycerols, triacylgcerols
One, two, and three FA esterfied to glycerol In adipose tissue as triacylglycerols (triglycerides) |
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6. What is the structure of phosphoacylglerols or glycerophospholipids?
What are they a major component of? |
FA esterified to positions 1 and 2 of glycerol moiety (linked w/ ester bonds)
Contain a phosphoryl at position 3 (with a polar head group) Components of cellular membranes |
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7. Which phosphoacyglcerols have no net charge at neutral pH?
Which one are negatively charged at neutral pH? |
1. Phosphatidylcholine
2. Phosphatidylethanoiame 1. Phsphaatidyleserine 2. Phosphatidic Acid |
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8. What is the backbone of sphingolipids?
What are they major components of? What do they play an important role in? |
Sphingosine
Myelin and membranes of brain and other nervous tissues Cell-cell and cell-ligand recognition |
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9. What does sphingomyelin contain?
What do sphingoglycolipids contain? What do cerebrosides contain? What do gangliosides contain? |
Phosphocholine
Carbohydrate A sugar residue Multiple sugar residues |
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10. What is cholesterol a major component of?
What do bile salts do? What is the structure of cholesterol like? What is cholesterol a precursor to? |
Cellular membranes and blood lipoprotein particles
Emulsify lipids in digestive tract 1. Has OH polar moiety 2. 4 ring structure that serves as precursor 3. Very hydrophobic portion Bile Acids (cholic acid) Steroid hormones (estradiol) |
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11. In an aqueous solution what do lipids form?
How are bilayers arranged? What stabilizes lipid bilayers |
Micelles or bilayers (form spontaneously)
Polar heads exposed to water and hydrophobic tails buried in the interior (core) Van der Waals |
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12. What type of lipids form micelles?
What is a miscelle and how is it arranged? What is a mixed micelle and what is it important in? |
Lipids that contain well-hydrated or large headgroups and only a single hydrocarbon chain
Sphere with a hydrophobic interior (core) Micelles mixed w/ phospholipid bilayer Role in triacylglycerol digestion |
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13. What are the important enzymes in digestion and absorption of TG?
Four... |
Pancreas lipase
Co-lipase Bile salts (cholesterol -> bile acids -> bile salts) Bicarbonate (released from pancreas) |
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14. What are lingual lipase and gastric lipase?
Where are they produced? |
Acid lipases w/ a pH optimum of 4.5
Lingual lipase -produced by glands in tongue and soft palate Gastric lipase -produced by stomach |
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15. What reaction do lingual and gastric lipases catalyze?
What do these lipases prefer to hydrolize? |
TG ---> diacylglycerol (DG) + FA
Short chain and medium chain ( less than or equal to 12 C) TG |
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16. What is cholecystokinin (CCK)?
What does it stimulate |
Hormone released from the upper small intestine
Stimulates synthesis of lingual and gastric lipases |
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17. Where is the major site of TGs digestion?
How do bile salts affect TG? Where are bile salts produced and stored? |
In the small intestine
Bile salts emulsify TG in the intestine Synthesized by liver and stored in gall bladder |
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18. How are bile acids at physiological pH?
What is bile salt then? |
Present as anions which exhibit detergent properties
Anionic form of bile acid It is the deprotonated species **bile salts form miscelles |
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19. How are bile salts made?
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1. Liver makes bile acids (cholic acid and chenodeoxycholic) from cholesterol
2. Conjugate bile acids with taurine and glycine 3. Conjugated bile acids are more polar and stronger anions thus better emulsifying agents |
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20. What is the major enzyme in TG digestion?
What does it do? Where does this occur? |
Pancreatic lipase
Converts TG to FAs and 2-monoacylglycerols In small intestine and convert TGs in the intestinal emulsion particles |
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21. What is the optimum pH of pancreatic lipase?
What is required for the binding of pancreatic lipase to emulsified TG particles? What is bicarbonate used for? |
pH optimum of 6-7
Colipase Used to raise the pH of the contents of the intestinal lumen to pH 6 for optimal action of lipase |
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22. What do the products of pancreatic lipase do?
Why do bile salts tend to form micelles? What can bile salt micelles do? |
Interact w/ bile salts to form mixed micelles
B/c on bile salts polar groups are located on one side and non-polar regions are on the other side Can solubilize other lipids to form mixed micelles |
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23. Where are the products of pancreatic lipase absorbed?
What happens next to the FAs and 2-monoacylglycerols? What is in chylocmicrons? |
Absorbed from micelle into intestinal epithelial cells
Resynthesized into TGs and packaged into chlyomicrons TGs, proteins, phospholipids, cholesterol, and other compounds |
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24. What are chylomicrons?
What happens to them? |
Lipoportein complex
Secreted into the lymph and ultimately enter the blood stream |
