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138 Cards in this Set
- Front
- Back
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What are the functions of lipids? |
Energy source Storage Cell structure Hormones Insulation |
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Lipids are soluble in what substance? |
Organic solvents |
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Lipids are insoluble in what substances? |
Water |
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What are lipoproteins? |
Proteins that transport lipids |
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What substances are transported by lipoproteins? |
Triglycerides Phospholipids Cholesterol Cholesteryl esters |
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Where are fatty acids found in the plasma? |
Bound to albumin |
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Fatty acids are constituents of what substances? |
Triglycerides Phospholipids |
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Fatty acids store energy in the form of what substance? |
Triglycerides |
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What are saturated fats? |
Molecules with hydrogen bonded to all carbons |
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What are unsaturated fats? |
Molecules with carbon-carbon double bonds |
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What substances are the essential fatty acids? |
Linolenic acid Linoleic acid |
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Arachidonic acid is synthesized from? |
Essential fatty acids |
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Why are there essential fatty acids? |
Substances aren't synthesized by the body and are obtained through diet |
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Saturated fats have what form at room temperature? |
Solid at room temperature |
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Unsaturated fats have what form at room temperature? |
Oils at room temperature |
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Where is the majority of fats stored? |
Tissues |
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Where are phospholipids synthesized? |
Liver |
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What type of lipid does not serve as a source of energy? |
Cholesterol |
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What are the functions of cholesterol? |
Converted in to vitamin D Converted to hormones Component of cell membrane Promote fat absorption |
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What is the function of lipoproteins? |
Deliver energy to peripheral cells |
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The surface of lipoproteins contains what substance? |
Apolipoproteins |
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What does apolipoprotein do for lipoproteins? |
Help maintain structural integrity Binding site for receptors Activate/inhibits various enzymes |
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What are the categories of lipoproteins? |
Chylomicrons Very-low-density lipoproteins Intermediate density lipoproteins Low-density lipoproteins High-density lipoproteins |
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What causes the milky appearance of plasma? |
Chylomicrons |
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Which lipoprotein is the largest and least dense? |
Chylomicrons |
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Where are chylomicrons produced? |
Intestine |
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What is the primary role of chylomicrons? |
Deliver dietary lipids to hepatic and peripheral cells |
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Where are VLDL produced? |
Liver |
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What is the function of VLDL? |
Carry triglycerides to cells for energy and storage |
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What is the function of LDL? |
Deliver cholesterol to peripheral cells and liver |
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What is the smallest and most dense lipoprotein? |
High-density lipoproteins |
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Where is HDL produced? |
Liver Intestines |
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What is the function of HDL? |
Gather excess cholesterol and return to the liver |
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What lipoprotein is used as the best indicator of cardiovascular disease? |
LDL |
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Where are apolipoproteins synthesized? |
Liver |
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What are the four pathways of lipoprotein metabolism? |
Lipid absorption Exogenous pathway Endogenous pathway Reverse cholesterol transport |
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What is the lipid absorption pathway? |
Lipid breakdown to be absorbed in the intestine |
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What is the exogenous pathway? |
Metabolism of chylomicrons |
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What is the endogenous pathway? |
Conversion of VLDL to LDL |
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What is the reverse cholesterol transport pathway? |
Gathering of excess cholesterol by HDL to be transported to the liver and excreted in bile |
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What are dyslipidemias? |
Abnormal concentration of lipids |
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What is arteriosclerosis? |
Hardening of arteries due to deposition of lipid in artery walls |
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What is hyperlipoproteinemia? |
Elevated lipoprotein levels |
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What is familial hypercholesterolemia? |
Elevated cholesterol levels due to a genetic defect in LDL receptors |
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What is the cause of hypertriglyceridemia? |
Imbalance between synthesis and clearance of VLDL in circulation |
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What is combined hyperlipoproteinemia? |
Elevated levels of both cholesterol and triglycerides |
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What is hypoalphalipoproteinemia? |
Decrease in circulating HDL |
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What is hypobetalipoproteinemia? |
Low LDL levels |
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What is the first marker released into circulation after a MI? |
Myoglobin |
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Where is myoglobin located in the body? |
Skeletal muscle Cardiac muscle |
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What is myoglobin? |
Iron and oxygen binding protein found in muscle |
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What is congestive heart failure? |
Progressive disease that affects the ability of the heart to pump blood |
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What are the markers of congestive heart failure? |
B-type natriuretic peptide NT-proBNP |
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What are the markers of coronary heart disease risk? |
hsCRP Homocysteine |
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What is the purpose of measuring homocysteine? |
Indicator of arterial inflammation |
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What is the purpose of measuring CRP? |
Indicator of inflammation |
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What is the purpose of measuring hsCRP? |
Used to determine risk factor for coronary heart disease |
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What is the half-life of myoglobin? |
9 minutes |
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What is the preferred biomarker to measure for cardiac necrosis? |
Troponin I/T |
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Which cardiac marker has the highest sensitivity and specificity? |
Troponin |
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What is the function of troponin? |
Bind calcium and regulate muscle contraction |
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What are the markers of cardiac damage? |
Troponin I/T Myoglobin CK/CKMB LDH |
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What is digestion? |
Process by which starches, proteins, lipids and nucleic acids are degraded to molecules for absorption and use in the body |
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What hormones does the pancreas secrete? |
Insulin Glucagon Gastrin Somatostatin |
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What is the function of insulin? |
Decrease plasma glucose |
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What is the function of glucagon? |
Increase plasma glucose |
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What is the function of gastrin? |
Stimulate gastric acid secretion |
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What is the function of somatostatin? |
Inhibit secretin |
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What test is used to diagnose cystic fibrosis? |
Sweat electrolyte test |
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What happens when the liver is completely nonfunctional? |
Death within 24 hours due to hypoglycemia |
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Where does the liver receive its blood supply? |
Hepatic artery Portal vein |
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How much of the livers blood supply comes from the hepatic artery? |
25% |
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How much of the liver blood supply comes from the portal vein? |
75% |
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What are the major cell types in the liver? |
Hepatocytes Kupffer cells |
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What are hepatocytes? |
Large cells radiating outward from the central vein |
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What are kupffer cells? |
Macrophages lining the sinusoids of the liver |
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What is the function of kupffer cells? |
Act as phagocytes engulfing bacteria, debris, toxins |
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What is the only organ capable of eliminating heme waste products? |
Liver |
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What is the principle pigment in bile? |
Bilirubin |
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What is bilirubin? |
Breakdown product of heme |
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Where does the majority of cholesterol come from? |
Produced by the liver |
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What is the most characteristic clinical manifestation of liver disease? |
Jaundice |
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When is jaundice visible? |
When the bilirubin results are >3.0 mg/dL |
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What are enzymes? |
Proteins that function as biologic catalysts |
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What are the characteristics of enzymes? |
Not consumed or altered Reusable Accelerate reaction speed |
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When are abundant amounts of enzymes present in the serum? |
After cellular injury or tissue damage |
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What are isoenzymes? |
Different forms of the same enzyme |
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What is an apoenzyme? |
Protein portion on an enzyme |
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What is a cofactor? |
Nonprotein compound necessary for enzyme activity |
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What is a holoenzyme? |
Active form of an enzyme |
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What is the activation energy? |
The amount of energy required to energize one mole of substrate to form the activated complex |
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How do enzymes affect chemical reactions? |
Lower the activation energy |
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What is first order kinetics? |
Rate of reaction is directly proportional to the substrate concentration |
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What is zero order kinetics? |
Rate of reaction depends on enzyme concentration only |
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What is the primary method used in the lab for measuring enzymes? |
Zero order kinetics |
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What factor influence enzyme action? |
Enzyme concentration Substrate concentration Temperature Inhibitors Activators pH |
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How does pH affect enzymes? |
Extreme pH can denature enzymes |
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How does temperature affect enzymes? |
Enzymes denature at higher temperatures |
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What is the optimal reaction temperatures of enzymes? |
37°C |
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What temperatures do enzymes denature? |
40-50°C |
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What are inhibitors? |
Substances that interfere with an enzyme reaction |
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What are the type of inhibitors? |
Competitive Noncompetitive Uncompetitive |
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What is a competitive inhibitor? |
Substances that compete with substrate to bind the active site |
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What is a noncompetitive inhibitor? |
Substance that binds with enzyme at a different site and preventing the reaction |
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What is an uncompetitive inhibitor? |
Substance that binds to the enzyme-substrate complex |
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What tissue sources contain creatine kinase? |
Skeletal muscle Heart muscle Brain tissue |
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What is the function of creatine kinase? |
ATP regeneration and storage of high energy creatine phosphate |
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CK values have diagnostic significance in what conditions? |
Acute myocardial infarction |
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What methodology is most commonly used to measure CK? |
Reverse reaction |
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What is the reverse reaction for creatine kinase? |
CK -> Hexokinase -> G6PD |
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What factors affect CK level testing? |
Hemolysis Light |
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What tissue sources contain LDH? |
Heart Liver Skeletal muscle Kidney Erythrocyte |
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What is the function of LDH? |
Interconversion of lactate and pyruvate in anaerobic metabolism |
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LDH values have clinical significance in what conditions? |
Pernicious anemia Hemolytic disorders |
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What is the cause of the LDH flip pattern? |
Elevation of LDH-1 due to cardiac necrosis or intravascular hemolysis |
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What is the most often used methodology to measure LDH? |
Lactate to pyruvate reaction - Wacker procedure |
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What factors affect LDH level testing? |
Hemolysis Unstable in serum |
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Where are the highest concentrations of AST? |
Cardiac tissue Liver Skeletal muscle |
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What is the function of aspartate aminotransferase? |
Transamination in amino acid metabolism |
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What methodology is used to detect AST? |
Karman method using malate dehydrogenase |
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What factors affect AST level testing? |
Hemolysis Stable 3-4 days |
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What tissue source has high concentrations of ALT? |
Liver |
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What clinical significance does ALT have? |
Hepatic disorders |
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What methodology is used to measure ALT? |
Enzyme reaction using LDH to catalyze pyruvate to lactate |
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What factors affect ALT level testing? |
Stable 3-4 days |
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What is the function of ALP? |
Removal of phosphate groups from different molecules at an alkaline pH |
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What is the function of ACP? |
Removal of phosphate groups from different molecules at an alkaline pH |
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What source has the most abundant activity of ACP? |
Prostate |
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What factors affect ACP levels? |
Separation of serum from cells |
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What tissues sources contain GGT? |
Kidney Brain Prostate Pancreas Liver |
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What clinical significant conditions are associated with GGT? |
Alcoholism |
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What tissue sources contain amylase? |
Pancreas Salivary glands |
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What is the function of amylase? |
Breaks down starch and glycogen |
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What factors affect amylase test level? |
Inhibited by triglycerides Morphine and opiates |
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What is the primary source of lipase? |
Pancreas |
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What is the function of lipase? |
Breaks down dietary triglycerides |
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What factors affect lipase test level? |
Hemolysis |
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What cofactor is needed to activate ALP? |
Magnesium |
