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65 Cards in this Set
- Front
- Back
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arachidonic acid
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20:4
CH3(CH2)4(CH=CHCH2)4(CH2)2COOH |
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linolenic acid
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18:3
CH3CH2(CH=CHCH2)3(CH2)6COOH |
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linoleic acid
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18:2
CH3(CH2)4(CH=CHCH2)2(CH2)6COOH |
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oleic acid
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18:1
CH3(CH2)7CH=CH(CH2)7COOH |
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palmitoleic acid
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16:1
CH3(CH2)5CH=CH(CH2)7COOH |
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arachidic acid
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20:0
CH3(CH2)18COOH |
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stearic acid
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18:0
CH3(CH2)16COOH |
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palmitic acid
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16:0
CH3(CH2)14COOH |
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myristic acid
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14:0
CH3(CH2)12COOH |
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lauric acid
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12:0
CH3(CH2)10COOH |
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Describe the solubility of lipids (3 things)
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- they are insoluble in water
- they are soluble in nonpolar solvents - they are soluble in solvents of lower polarity |
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List the three functions of lipids:
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- storage
- structure of membranes - chemical messengers |
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List the 4 types of lipids:
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- simple lipids
- complex lipids - steroids - prostaglandins, thromboxanes, leukotrienes |
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What is the function of primary messengers?
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They deliver signals from one part of the body to another.
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What is the function of secondary messengers?
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They mediate the hormonal response.
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Describe the structure of a triglyceride.
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A triester of glycerol with three fatty acids.
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The saponification of a triglyceride produces...
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...glycerol and a mixture of fatty acid salts.
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List the two types of complex lipids:
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- phospholipids
- glycolipids |
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Describe the structure of phospholipids:
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An alcohol with two fatty acids and a phosphate ester.
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Describe the structure of glycolipids:
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A sphingosine, a fatty acid and a carbohydrate. Since the sphingosine + fatty acid are considered a ceramide, then another correct answer would be a ceramide and a carbohydrate.
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What is a ceramide?
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A sphingosine combined with a fatty acid.
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Describe a sphingosine:
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An 18-carbon amino alcohol with an unsaturated hydrocarbon chain.
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Explain how the carbohydrate is attached to the alcohol back bone in glycolipids.
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A beta-glycosidic bond joins the carbohydrate unit with the ceramide portion of the molecule.
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What are the two types of phospholipids?
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- glycophospholipids
- sphingolipids |
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Describe the structure of glycerophospholipids:
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GLYCEROL + fatty acid + phosphate ester
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Describe the structure of sphingolipids:
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SPHINGOSINE + fatty acids + phosphate ester
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What is the major function of complex lipids?
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They form the membranes around cells and around small structures within cells (organelles).
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What are the three most abundant fatty acids in glycerophospholipids?
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- palmitic acid (16:0)
- stearic acid (18:0) - oleic acid (18:1) |
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What is phosphatidylcholine?
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A glycerophospholipid with the phosphate esterified to choline.
It is also known as lecithin. |
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What are cephalins?
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A glycerophospholipid whose phosphate is esterified to either serine or ethanolamine.
Known as phosphatidylethanolamine or phosphatidylserine. |
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What are the two types of glycolipids?
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- cerebrosides
- gangliosides |
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Where in the human body can cerebrosides be found?
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In the brain and nerve synapses.
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Where in the human body can gangliosides be found?
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In the nervous system.
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What is the most abundant and most important steroid in the body?
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cholesterol
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What are the four kinds of lipoproteins?
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- HDL
- LDL - VLDL - chylomicrons |
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What is the purpose of lipoproteins?
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They carry cholesterol throughout the body.
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Describe the structure of lipoproteins:
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A core of hydrophobic lipid molecules surrounded by a shell of hydrophilic molecules (proteins and phospholipids).
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Explain VLDL's role in the human body:
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VLDL is assembled in the liver with triglycerides, cholesterol and lipoproteins. It travels through the blood serum to the muscle and fat tissue capillaries where the triglycerides and proteins (except apoB-100) are removed and it becomes LDL.
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Explains LDL's role in the human body:
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LDL carried cholesterol to the cells where it binds to specific LDL receptors. LDL is then taken into the cells where enzymes liberate the free cholesterol. The cholesterol can now be used as a component of the cell membrane.
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Explain HDL's role in the human body:
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HDL transports cholesterol from the peripheral tissues to the liver as cholesteryl esters where they can be used for the synthesis of steroid hormones and bile acids. HDL then returns to the blood for recirculation.
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How are levels of LDL controlled by the body?
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When concentration of LDL inside the cells is high, the number of LDL receptors drops. As plasma level increases and the concentration within the cells decrease, LDL receptors are added.
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What is the major malfunction in familial hypercholesterolemia?
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There are not enough LDL receptors and the plasma cholesterol level soars to as high as 680mg/dL.
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How do statin drugs work?
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They inhibit the synthesis of cholesterol and stimulate the synthesis of LDL receptors by blocking HMG-CoA reductase.
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What is the benefit of high levels of HDL?
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It removes cholesterol form plaques in the arteries and delivers it to the liver, reducing the risk of atherosclerosis.
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What is the starting material for the synthesis of steroid hormones?
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cholesterol
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Where are adrenocorticoid hormones produced?
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The adrenal glands.
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What are the two types of adrenocorticoid hormones?
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- mineralocorticoids
- glucocorticoids |
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What do mineralocorticoids do?
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They regulate the concentration of ions.
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What do glucocorticoids do?
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They control carbohydrate metabolism.
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What is the most important mineralocorticoid and what is its role?
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Aldosterone. It controls tissue swelling. Increased secretion of aldosterone enhances reabsorption of Na+ and Cl- in the kidneys and increases the loss of K+.
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What is the major glucocorticoid and what is its role?
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Cortisol. It is secreted in response to stress and anxiety. It increases the glucose and glycogen concentrations in the body. It also has a strong anti-inflammatory effect.
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What is the purpose of bile salts?
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They emulsify dietary fats and aid in their absorption and digestion.
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Bile salts are ______ products of cholesterol.
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___ ___ are oxidation products of cholesterol.
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Bile salts are powerful _____.
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___ ___ are powerful detergents.
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In what two ways to bile salts remove excess cholesterol?
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- They are themselves breakdown products of cholesterol.
- They solubilizedepositied cholesterol in the form of bile salt-cholesterol products. |
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What are prostaglandins?
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Prostaglandins are a family of compounds that have the 20-carbon skeleton of prostanoic acid.
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What is the difference in structure of PGE2 and PGF2a?
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In PGE2, there is a carbonyl group on carbon 9 and a hydroxyl group on carbon 11. In PGF2a, there are hydroxyl groups on carbons 9 and 11.
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How are prostaglandins formed?
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A ring closure at carbons 8 and 12 of archidonic acid is catalyzed by the enzyme cyclooxygenase (COX) in response to specific physiologic triggers.
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What two COX enzymes occur and what are their effect?
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COX-1 and COX-2.
COX-1 catalyzes the normal physiologic production and is responsible for uterine contractions in the induction of labor, decongestion, and lowering blood pressure. COX-2 is responsible for the production of prostaglandins in inflammation. |
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How is COX-2 activated?
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When a tissue is injured, special inflammatory cells invade and interact with the resident cells, causing activation of COX-2 enzymes.
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What is the structural difference of thromboxanes?
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Thromboxanes have a cyclic acetal in their ring.
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What is the effects of thromboxanes on the human body?
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They induce platelet aggregation and vasoconstriction.
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How do aspirin and NSAIDs work?
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They inhibit the COX enzyme, preventing synthesis of prostaglandins.
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What is the structural difference in leukotrienes compared to the prostaglandins and thromboxanes?
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They do not have a ring.
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What effects do leukotrienes have on the body?
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They are involved in asthma and allergic reactions and act to sustain inflammatory reactions.
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