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43 Cards in this Set
- Front
- Back
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Name some lipid functions.
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Energy (TG)
Membranes (structural) Signals (hormones, messengers, prostaglandins) Cofactors (Vitamin A, D, E, and K) Transport (isoprenoid transporters--dolichols) |
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Name 1:0, 2:0, 3:0 and 4:0 fatty acids.
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Formic acid (1:0)
Acetic acid (2:0) Propionic acid (3:0) Butyric acid (4:0) |
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Name 16:0, 18:0, and 20:0 fatty acids.
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Palmitic acid (16:0)
Stearic acid (18:0) Arachidic acid (20:0) |
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What effect does an increase in the length of the hydrocarbon chain have?
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Increase in hydrophobicity
Increase in melting temperature All do to increased "packing" of acyl groups. |
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Describe the difference between delta and omega nomenclature.
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Delta:
Start numbering from carboxyl end, where elongation occurs. Numbers all double bonds (i.e. 18:2 delta 6,9) Omega: Number from reduced end. Only number first double bond. (ie 18:2 omega 9) |
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What are the different omega families?
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omega 3, 6, 7, and 9
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Describe the limitations of the desaturase enzyme.
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1. Works from the delta end
2. Can only reach 9 carbons 3. Can not reach past first inserted double bond 4. All double bonds are CIS |
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What is the angle of a cis double bond?
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about 120 degrees
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Why is arachidonic acid important? What is its structure?
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1. Used to make prostaglandins and leukotrienes
2. 20:4 (w6) or 20:4 (d5,8,11,14) |
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What is the essential fatty acid needed to build arachidonic acid? Build it.
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18:2 (w6) (d9,12)
desaturated to make d6,9,12 elongated to make 20:3 (d8,11,14) desaturated to make d5,8,11,14 |
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Which omega 3 and omega 6 fatty acids can humans make?
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None
Omega 3 from fish oils -- algae Omega 6 from plants |
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Explain how saturation and unsaturation can effect membrane liquidity.
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Saturation makes membranes rigid
Unsaturation makes membranes fluid |
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Which plasma membrane layer has relatively more unsaturated lipids?
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inner layer
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What is the reactive intermediate that is required to make triglycerides and phospholipids?
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Phosphatidic acid
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What compound is able to transfer methyl groups?
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S-Adenosyl methionine (SAM)
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Addition of methyl groups can change Ethanolamine to what?
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Choline
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A decarboxylase can make phosphatidyl serine into what?
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Phosphatidyl ethanolamine
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Why is phosphatidyl insitol important? Which layer of the plasma membrane would it be primarily found on?
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Can be cleaved to form IP3, a signaling molecule.
Found on the cytosolic side. |
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Describe the composition of cardiolipin and where it can be found?
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4 Fatty acids
2 Phosphates 3 Glycerols Found in the inner mitochondrial membrane |
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What is unique about plasmalogen structure?
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An ether-vinyl group in the alpha-1 position on the glycerol, with a choline head group.
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Name an important plasmalogen.
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Platelet Activating Factor
Alpha-2 position on the glycerol is acetic acyl group. |
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What forms the backbone of a sphingosine?
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Serine
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What acyl-CoA will bind the alpha-1 position on sphingosine?
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Palmitoyl-CoA (16:0)
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Describe the difference between a ceramide and a sphingomyelin.
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Sphingomyelin has a choline head group.
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How can a ceramide be made into a cerebroside?
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Addition of UDP-Gal or UDP-Glucose
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What are cerebrosides and gangliosides used for?
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signaling
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What enzyme makes prostaglandins?
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Cyclo-oxygenase (COX)
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Which prostaglandins increase and decrease platelet aggregation?
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PG-I (prostacyclin) - decreases
TBX (thromboxane) - increases |
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What enzyme is used to form leukotrienes?
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5-lipoxygenase
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Discuss the main functions of LTB4 and LTC4.
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LTB4 - chemotaxic
LTC4 - smooth muscle control (asthma) |
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What tripeptide can be added to LTA4 to make LTC4?
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Glutathione (Glu-Cys-Gly)
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How is LTD4 made?
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Removal of gamma-Glu from LTC4
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How is LTE4 made?
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Removal of Gly from LTD4
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What are autocoids?
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Prostaglandins and leukotrienes.
Can effect the same gland that produced them. |
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Where does the cell get arachidonic acid for prostaglandin and leukotriene formation?
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1. Free (digested)
2. From the plasma membrane, either 20:4 or 18:2 |
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What enzyme is needed to remove acyl groups from a phospholipid?
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Phospholipase (A1, A2)
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Where does phospholipase C cleave?
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Between the carbon and phosphate
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Where does phospholipase D cleave?
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Cleaves off the head (ie inositol, choline, ethanolamine...)
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What non-steroidal medications will inhibit cyclo-oxygenase? Why would be want to do that?
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NSAIDs, Aspirin, Tylenol, Mortin, etc.
Blocks the production of prostaglandins |
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What are the effects of cortisol?
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Blocks inflammatory response by blocking phospholipase A2
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Which fatty acid is increased and which is decreased in cystic fibrosis?
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20:4 increased
22:6 decreased (docosahexaneoic acid) (DHA) |
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DHA was able to reduce lung infections in cystic fibrotic mice. Why?
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22:6 might create none productive prostaglandins.
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Why is cholesterol an essential compound?
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1. Structurally important for membranes
2. hormones 3. Vitamin D 4. Bile salts |
