front 1 What is the product of glycolysis in red blood cells and exercising muscle? | back 1 Lactate |
front 2 A modified B oxidation leads to the formation of acetyl-CoA and H2O2 and occurs in what organelle? | back 2 Peroxisome |
front 3 Which reducing equivalents are generated and used to form ATP during B oxidation of fatty acids? | back 3 FADH2 and NADH |
front 4 What do adipose TAGs supply during a fasting state? | back 4 Fatty Acids |
front 5 Why can red blood cells use only glucose as a form of energy? | back 5 They lack mitochondria |
front 6 What compounds are used in gluconeogenesis as carbon sources | back 6 Lactate, glycerol, amino acids |
front 7 During starvation, carbohydrates are depleted and free fatty acids are mobilized, which leads to what process? | back 7 Ketosis |
front 8 Urea is formed from amino acids by which organ? | back 8 Liver |
front 9 The last step in the B oxidation of fatty acids involves the conversion of 3-ketoacyl-CoA to acyl-CoA and acetyl-CoA by which enzyme? | back 9 Thiolase |
front 10 In a state of starvation, what organ increases it use of ketone bodies as a major energy source? | back 10 Brain |
front 11 When glucose is produced from non-carb compounds, it is called what? | back 11 Gluconeogenesis |
front 12 What part of TAG is converted to glucose during periods of prolonged fasting? | back 12 Glycerol |
front 13 The catabolism of fatty acids requires what form of energy? | back 13 ATP |
front 14 In the B oxidation of fatty acids, carbons are cleaved from acyl-CoA molecules on which end? | back 14 Carboxyl |
front 15 What are the insulin and glucagon levels of a person in a basal state? | back 15 Insulin low, glucagon high |
front 16 What enzyme is used to form acylcarnitine? | back 16 Carnitine palmitoyltransferase-I (CPT-I) |
front 17 The formation of ketone bodies primarily occurs in what organ? | back 17 Liver |
front 18 After at least one day of fasting, what is the sole source of blood glucose? | back 18 gluconeogenesis |
front 19 After how many days of fasting does the body begin producing ketone bodies for fuel? | back 19 3 days |
front 20 How many mols of ATP are produced in the citric acid cycle for every 8 mol of acetyl-CoA formed? | back 20 10 |
front 21 What are the three types of ketone bodies? | back 21 B-hydroxybutyrate, acetoacetate, acetone |
front 22 Which amino acid remains in the muscles in a state of starvation | back 22 Leucine |
front 23 When partially digested food enters the intestine, the hormone ______________ is secreted by the intestine, which signals the gallbladder to contract and release bile acids, and then the pancreas to release digestive enzymes. | back 23 Cholecystokinin |
front 24 Laboratory results for a patient with uncontrolled Type I diabetes mellitus reveal hyperglycemia (634 mg/dL) and hypertriglyceridemia (498 mg/dL). The most likely cause of the hypertriglyceridemia in this patient is which of the following? | back 24 Decreased lipoprotein lipase activity |
front 25 Bile slats must reach a particular concentration within the intestinal lumen before they are effective agents for lipid digestion. This is because of which of the following? | back 25 The bile salts solubility in the lumen is a critical factor |
front 26 What are the components of chylomicrons? | back 26 Chylomicrons are formed by triglycerides, phospholipids, cholesterol and apoB48 |
front 27 The apoproteins B-48 and B-100 are similar with respect to which of the following? | back 27 They are synthesized from the same gene |
front 28 LCAT is a plasma enzyme and its substrate is cholesterol contained in _____. | back 28 HDL |
front 29 Elevated serum TG levels can occur due to a number of factors. which one of the following factors reduces TG levels? | back 29 Under production of apo B-100 |
front 30 The major enzyme that digests dietary TAGs is ______________ produced in the pancreas. Pancreatic lipase is secreted along with another protein, colipase, in response to the release of the cholecystokinin from the intestine. | back 30 Lipase |
front 31 Which cells produce LPL? | back 31 Adipose, Muscle, and Lactating mammary gland cells |
front 32 Which hormone stimulates the synthesis of lipoprotein lipase? | back 32 Insulin |
front 33 What is the starting point for the LCAT pathway? | back 33 Lecithin |
front 34 In a fasting state, what is released from adipose stores for gluconeogenesis? | back 34 Fatty acids and glycerol |
front 35 What is the optimal pH for digestive enzymes in the intestine? | back 35 6 |
front 36 What protein activates lipoprotein lipase? | back 36 Apoprotein CII |
front 37 Chylomicron remnants are taken up by which receptors found in the liver? | back 37 Apoprotein E receptors |
front 38 Which apoprotein is responsible for activating the LCAT pathway? | back 38 ApoAI |
front 39 Which apoprotein inhibits lipoprotein lipase? | back 39 ApoCIII |
front 40 Which of the following is produced in the blood? | back 40 LDL |
front 41 Which is the largest of the lipoproteins? | back 41 Chylomicrons |
front 42 In the LCAT pathway, what is cholesterol converted to? | back 42 Cholesterol ester |
front 43 Fatty acids released from triacylglycerols must form complexes with what molecule to travel in the blood? | back 43 Albumin |
front 44 The synthesis of chylomicrons occurs in which intestinal cellular organelle? | back 44 Smooth ER |
front 45 Where are chylomicrons secreted? | back 45 Lymph |
front 46 What is lipogenesis stimulated by to convert glucose to fatty acids? | back 46 Insulin |
front 47 Which apoprotein is a ligand for the LDL receptor? | back 47 ApoB100 |
front 48 What lipoprotein contains triacylglycerol, apolipoprotein B-48, phospholipids, and cholesterol esters? | back 48 Chylomicron |
front 49 Chylomicron remnants are taken up by which receptors found in the liver? | back 49 Apoprotein E receptors |
front 50 What is lipogenesis stimulated by to convert glucose to fatty acids? | back 50 Insulin |
front 51 Lingual and gastric lipases preferentially hydrolyze fatty acid chains of what size? | back 51 Short and medium chains |
front 52 How long after the start of a meal do nascent chylomicrons enter the bloodstream? | back 52 1 to 2 hours |
front 53 The high solubility of cholesterol in blood is due to plasma lipoprotein(s). | back 53 VLDL and LDL |
front 54 What percent of cholesterol in plasma lipoproteins exists in the form of cholesterol esters? | back 54 70% |
front 55 What percent of the cholesterol in plasma exists in the form of free cholesterol? | back 55 30% |
front 56 Bile becomes a very efficient detergent when conjugated to: | back 56 Amino acids (glycine and taurine) |
front 57 Can cholesterol be metabolized to CO2 and water in humans? | back 57 No |
front 58 Which one of the following conditions can induce the formation of gallstones? | back 58 Excess HMG-CoA reductase activity, Reduced levels of cholesterol & a-hydroxylase, High levels of deoxycholate that inhibit CYP7A1 enzyme activity (all of the above) |
front 59 The cholesterol pool of the body is derived from the absorption of dietary cholesterol and biosynthesis primarily in: | back 59 Liver and intestine |
front 60 You decide to treat a patient who has very high levels of serum cholesterol with the statin drug Lipitor (atorvastatin). You know that this drug acts in the metabolic pathway leading to the synthesis of cholesterol. The substrate for the enzyme inhibited by the statin d | back 60 HMG-CoA |
front 61 The initial and rate-limiting step of bile synthesis is achieved by: | back 61 7 a-hydroxylase, CYP7A1 |
front 62 Excretion of cholesterol is by way of the liver and gallbladder through the intestine in the form of bile acids | back 62 True |
front 63 Which disease is a result of abnormal, deficient, or inactive LPL? | back 63 Familial lipoprotein lipase deficiency |
front 64 HDL transfers which proteins to chylomicrons and VLDL? | back 64 ApoE and apoCII |
front 65 How does HDL transport cholesterol or cholesterol esters to the liver? | back 65 CETP |
front 66 HDL converts cholesterol to cholesterol esters via which pathway? | back 66 LCAT |
front 67 High levels of which cholesterol are especially atherogenic? | back 67 LDL |
front 68 Which of the following diseases is believed to be both genetic and environmental? | back 68 Hypercholesterolemia |
front 69 How is cholesterol packaged when in the intestines? | back 69 Chylomicrons |
front 70 What is the precursor for cholesterol synthesis? | back 70 Acetyl-CoA |
front 71 Which lipoprotein returns dietary lipids to the liver? | back 71 Chylomicron remnants |
front 72 What adds stability to the phospholipid bilayer of membranes? | back 72 Cholesterol |
front 73 What occurs to the LDL receptors in people with familial hypercholesterolemia? | back 73 Lack LDL receptor protein |
front 74 A majority of synthesized cholesterol is secreted from which type of cell? | back 74 Hepatocytes |
front 75 Which disease leads to premature coronary heart disease due to atherosclerosis and thrombosis due to the inhibition of fibrinolysis? | back 75 Familial lipoprotein A excess |
front 76 Which proteins are responsible for moving unwanted or excess cholesterol from enterocytes to the gut lumen? | back 76 ABCG5 and ABCG8 |
front 77 What enzyme is responsible for releasing free fatty acids for milk production? | back 77 LPL |
front 78 What member of the ABC family is required for reverse cholesterol transport and HDL biogenesis? | back 78 A1 |
front 79 The presence of a fatty streak is early gross evidence of what type of formation? | back 79 Atherosclerotic plaque |
front 80 What do nascent VLDL particles accept from HDL particles to form mature VLDL particles? | back 80 Apolipoproteins |
front 81 What does VLDL convert to initially? | back 81 IDL |
front 82 After digestion by lipase, LDL returns to the liver and enters cells via what process? | back 82 Endocytosis |
front 83 Cholestyramine leads to excretion of what product? | back 83 Bile acids |
front 84 The second pathway of biosynthesis and degradation of bile acids may occur in what organelle? | back 84 Mitochondria |
front 85 What structural part of bile salts makes them well suited for micelle formation? | back 85 Hydrophobic, hydroxyl group |
front 86 Which of the following is a primary bile acid? | back 86 Taurocholic acid |
front 87 What forms micelles with fatty acids released from dietary triglycerides? | back 87 Bile salts |
front 88 Which of the following is a secondary bile acid? | back 88 Lithocholic acid |
front 89 What effect does rising levels of cholesterol and bile acids have on HMG-CoA reductase? | back 89 Proteolysis susceptibility |
front 90 What does the lipase/colipase complex promote the degradation of? | back 90 Triacylglycerol |
front 91 Bile acids improve the absorption of which vitamins? | back 91 A,D,E,K |
front 92 Where does fat emulsification and micelle formation occur? | back 92 Small intestine |
front 93 How does cholestyramine lower cholesterol levels in the blood? | back 93 Binds bile acids to limit reabsorption |
front 94 Once micelles transport degradation products to the mucosa, what occurs to the products? | back 94 Reassembly into triacylglycerols |
front 95 The production of secondary bile acids occurs in which organ? | back 95 Intestines |
front 96 In what organ is bile synthesized? | back 96 Liver |
front 97 Primary and secondary bile acids are absorbed in the intestines and returned to which organ? | back 97 Liver |
front 98 The presence of bile and fatty acids in the duodenum increases the level of which hormone? | back 98 Secretin |
front 99 What is the rate-limiting step in the synthesis of bile acids? | back 99 CYP7A1 reaction |
front 100 What property do bile acids have that promotes the encircling and degradation of triglycerides and phospholipid fat particles in food? | back 100 Detergent |
front 101 Bile salts generated with α-hydroxyl groups at the 3 and 7 positions form which set of bile salts? | back 101 Chenocholate |
front 102 The conjugation of glycine and taurine occurs in what part of the cell? | back 102 Peroxisome |
front 103 What are the four classes of plasma lipoproteins in normal fasting humans? | back 103 HDL, LDL, IDL, VLDL |
front 104 The protein component of a lipoprotein particle is called | back 104 apolipoproteins |
front 105 True or False: The HDL particle has higher percentage of protein than VLDL particle | back 105 True |
front 106 True or False: VLDL is synthesized in the intestine and liver | back 106 False |
front 107 Lipoprotein lipase is located on the surface of- | back 107 endothelial cells of capillaries |
front 108 Which apo protein is required for activation of lipoprotein lipase? | back 108 ApoC-II |
front 109 The pKa of the bile acids is approximately 6. The intestinal lumen has a pH of 6. That means- | back 109 Half of the bile molecules are present in the protonated (acid) and the other half are ionized (salt). |
front 110 When bile salts form conjugates with taurine or glycine their pKa values decrease to as low as 2. What would you expect to see in the intestinal lumen that has a pH of 6? | back 110 Majority of bile molecules are in ionized form (salt) |
front 111 What role does intestinal bacteria play regarding bile salt molecules? | back 111 Deconjugate and Dehydroxylate bile salts |
front 112 Which type of secondary bile salt/acid has the least solubility in the intestinal lumen and its major fate is excretion? | back 112 Lithocholic acid |
front 113 What is the rate of HMG-CoA reductase mRNA synthesis controlled by? | back 113 SREBP |
front 114 The synthesis of all steroid hormones begins with the conversion of cholesterol to what compound? | back 114 Progesterone |
front 115 All the carbons of cholesterol are derived from which precursor? | back 115 Acetyl-CoA |
front 116 SREBPs are integral proteins of what cellular organelle? | back 116 Endoplasmic reticulum |
front 117 How many condensed molecules of acetyl-CoA are required to form HMG-CoA? | back 117 3 |
front 118 How do statins lower cholesterol? | back 118 Inhibit HMG-CoA reductase |
front 119 In what part of the cell does cholesterol synthesis occur? | back 119 Cytosol |
front 120 At what point is the SREBP:SCAP complex transported to the Golgi apparatus? | back 120 decrease in cholesterol |
front 121 What are the three main organs, aside from the liver, in which significant quantities of cholesterol are biosynthesized? | back 121 Gut, adrenal cortex, gonads (ballz) |
front 122 How does hyperinsulinemia change the molecule of HMG-CoA reductase? | back 122 Leads to dephosphorylation |
front 123 What effect does increased glucagon levels have on HMG-CoA reductase? | back 123 Inactivation |
front 124 How many fused cyclic rings does the cholesterol molecule contain? | back 124 4 |
front 125 What is the precursor for glucocorticoids, androgens, and estrogens? | back 125 Cholesterol |
front 126 The conversion of HMG-CoA to mevalonic acid is catalyzed by which enzyme? | back 126 HMG-CoA reductase |
front 127 What class of steroid hormones contains 21 carbons? | back 127 Glucocorticoids |
front 128 Two molecules of farnesyl pyrophosphate undergo a fusion reaction to yield what compound? | back 128 Squalene |
front 129 Cholesterol is stored as cholesterol esters in the cells of what organ? | back 129 Adrenal cortex |
front 130 What is the energy source for cholesterol synthesis? | back 130 ATP |
front 131 In order for mevalonate to form, what compound must be reduced via catalyzation? | back 131 HMG-CoA |
front 132 The synthesis of what compound is considered the rate-limiting step in cholesterol formation? | back 132 Mevalonate |
front 133 What type of bond helps nucleotide molecules form RNA and DNA strands? | back 133 Phosphodiester |
front 134 Gout is a metabolic disorder of which of the following? | back 134 Purine catabolism |
front 135 The uric acid pathway occurs in what organ? | back 135 GI tract |
front 136 What is the end product of purine catabolism in humans? | back 136 Uric acid |
front 137 Why does abnormal catabolism of pyrimidines not form as many serious diseases as catabolism of purines? | back 137 Pyrimidines form highly water soluble products |
front 138 Which of the following is produced by the catabolism of pyrimidines? | back 138 CO2 |
front 139 How many ring structures does adenine have? | back 139 2 |
front 140 What is formed from ribose, glycine, aspartate, glutamine, tetrahydrofolate, and CO2? | back 140 IMP |
front 141 Disorders of β-alanine and β-aminoisobutyrate metabolism arise from defects in which enzymes? | back 141 Pyrimidine catabolism |
front 142 Which component of nucleosides and nucleotides is important in energy storage and signaling? | back 142 Phosphate group |
front 143 Which purine molecule is converted into uric acid and excreted in the urine? | back 143 Xanthine |
front 144 Which molecules have a pyrimidine ring in their structures? | back 144 Cytosine, thymine and uracil |
front 145 Adenosine is converted to what compound via adenosine deaminase in the uric acid pathway? | back 145 Inosine |
front 146 Which molecules have a purine ring in their structures? | back 146 Adenine and guanine |
front 147 Nucleotides are similar in structure to nucleosides except for the addition of what molecule? | back 147 Phosphate |
front 148 What medical conditions could result from mistakes or deficiencies in nucleosides or nucleotides? | back 148 Death |
front 149 How many ring structures does thymine have? | back 149 1 |
front 150 One of the many functions of nucleosides and nucleotides includes which of the following? | back 150 Maintaining/transferring genetic information |
front 151 Which molecule has a nitrogenous base and a five-carbon carbohydrate? | back 151 Nuceloside |
front 152 How does allopurinol work as a treatment for gout? | back 152 Reduces production of uric acid |
front 153 What enzyme is activated by increased glutamate, N-acetylglutamic acid, and/or arginine concentrations? | back 153 Carbamoyl phosphate synthetase |
front 154 Conversion from citrulline to argininosuccinate requires? | back 154 a single ATP molecule is required for the reaction of citrulline to argininosuccinate |
front 155 Glutamate donates the first amino group for urea; which molecule donates the second? | back 155 Aspartate |
front 156 Nitrogen-based waste products are excreted as what compound? | back 156 Urea |
front 157 Which of the following is an essential amino acid? | back 157 Lysine |
front 158 Amino acids are metabolized via which pathway? | back 158 Citric acid cycle, glycolysis |
front 159 The enzyme argininosuccinate lyase is used during which reaction? | back 159 Argininosuccinate to arginine |
front 160 The reaction of CO2 and NH4 is catalyzed by CPS-I and forms carbamoyl phosphate in the urea cycle. Where does this reaction occur? | back 160 Mitochondria |
front 161 The urea cycle occurs mostly in what bodily organ? | back 161 Liver |
front 162 What characteristic of amino acids makes them useful for making a variety of fuels for the body? | back 162 Carbon skeleton |
front 163 How many ATP molecules are required in the urea cycle? | back 163 3 |
front 164 What does glutamate donate for the conversion to urea? | back 164 NH3 |
front 165 The production of urea occurs in what part of the cell? | back 165 Cytosol |
front 166 The conversion of what molecule allows for the utilization, generation, and/or storage of ammonia? | back 166 Α-ketoglutarate to glutamate |
front 167 What does carbamoyl phosphate combine with to form citrulline? | back 167 Ornithine |
front 168 What is used as building blocks for proteins, nucleic acids, hormones, neurotransmitters, antioxidants, and signaling molecules | back 168 Amino Acids |
front 169 Which of the following is in the correct order for the urea cycle? | back 169 Carbamoyl phosphate, citrulline, argininosuccinate |
front 170 What does α-ketoglutarate convert to? | back 170 Glutamate |
front 171 How many amino groups are used for the conversion of products to urea? | back 171 2 |
front 172 What is the function of Argininosuccinate synthetase? | back 172 Conversion from citrulline to arginiosuccinate |
front 173 Urea is produced in the | back 173 Liver |
front 174 Which amino acid donates the second nitrogen atom during the Urea Cycle? | back 174 Aspartate |
front 175 Ammonia formed in muscle and other organs is transported through the blood circulation in nontoxic form as- | back 175 Glutamine and Alanine |
front 176 Fumarate from urea cycle is a source for- | back 176 Glucose, Aspartate, ATP energy |
front 177 How is the urea cycle regulated? | back 177 by CPS-I |
front 178 A 9-month-old infant was admitted to the hospital in a coma and a temperature of 103°F. His pulse was elevated, his liver was enlarged, and an electroencephalogram was grossly abnormal. Intravenous glucose was administered. He improved rapidly and came out of the coma in 24hrs. Analysis of his urine showed abnormally high amounts of glutamine, which suggested a high blood ammonium ion concentration. Which enzyme may be defective in this patient? | back 178 Glutaminase |
front 179 The most important amino acids as a source of fuel that generate a large amount of NADH and FADH2 are: | back 179 Valine, Leucine, and Isoleucine |
front 180 The amount of fumarate used to form ATP is approximately equal to that required for the urea cycle and gluconeogenesis, meaning that- | back 180 The liver gains no net energy |
front 181 Why do caloric restriction and low blood glucose increase the activities of glutamate dehydrogenase? | back 181 The activity is raised in order to increase the amount of a-ketoglutarate produced, which can be used to provide energy. |
front 182 (True or False) Any urea that enters the intestinal tract is cleaved by urease-containing bacteria in the intestinal lumen and the ammonia is absorbed back into the body | back 182 True |