UNE Biochemistry Unit 3

UNE Biochemistry Unit 3 Which of the following lipoproteins distributes dietary lipids? chylomicron The interaction of chylomicrons with lipoprotein lipase is stimulated by which of the following Apo proteins? ApoC II Nascent chylomicrons are synthesized in which tissue? Intestine Bile salts are synthesized from cholesterol and are used for the emulsification of dietary lipids. What is the primary fate of bile salts during digestion? They are reabsorbed in the ileum Nascent chylomicrons interact with HDL particles and obtain which of the following Apo protiens? ApoCII and ApoE The activity of pancreatic lipase is inhibited by which of the following compounds? Bile salts Which of the following statements regarding lipid digestion and absorption is true? A. The products of lipid digestion travel in the circulatory system in the form of micelles. B. The products of lipid digestion diffuse into capillaries in the vicinity of the intestinal epithelium. C. Pancreatic lipase emulsifies lipids. D. The products of lipid digestion are resynthesized into triacylglycerols in intestinal epithelial cells. E. In the absence of bile salts, no digestion of lipids would occur. The products of lipid digestion are resynthesized into triacylglycerols in intestinal epithelial cells. Under fasting conditions (Ratio of insulin to glucagon 1), elevated glucagon will activate which of the following enzymes? Hormone sensitive lipase VLDL particles are characterized by which of the following apoproteins? Apo B 100 An increase in insulin leads to which of the following metabolic shifts? Acetyl CoA carboxylase will become dephosphorylated and active Biotin is a cofactor required for which of the following enzymes? A and B (Acetyl CoA carboxylase and Pyruvate carboxylase) The first step in fatty acid synthesis is the formation of ________ from acetyl CoA and carbon dioxide. malonyl CoA Insulin increases the activity of all of the following enzymes except: Hormone sensitive lipase Which of the following is the regulatory enzyme for fatty acid synthesis? AcetylCo A carboxylase Which of the following is the regulated step of fatty acid synthesis in eukaryotes? A. Carboxylation of acetyl CoA B. Transportation of mitochondrial acetyl CoA into the cytosol C. Assembly of the fatty acid chain D. All of the above Carboxylation of acetyl CoA Under conditions of starvation, all of the following are true except: A. the brain will preferentially be oxidizing ketones B. hormone sensitive lipase will be phosphorylated C. AMP kinase will be active D. Malonyl CoA will be elevated Malonyl CoA will be elevated Which of the following proteins is responsible for the transfer of ApoB48 to nascent chylomicrons before secretion into circulation? Microsomal transfer protein (MTP) The process of β-oxidation generates all of the following compounds except: A. Acetyl CoA B. NADPH C. NADH D. FADH2 NADPH During the fasted state, lipolysis is facilitated by the action of hormone sensitive lipase. This enzyme requires which of the following post - translational modification for activation? Phosphorylation Adiponectin is secreted from adipocytes. One of the primary roles of adiponectin is to activate AMPK in skeletal muscle which enhances the activity of which of the following pathways? β oxidation When the processes of glucose oxidation is elevated, the acetyl CoA produced will allosterically activate which of the following enzymes leading to an increase in the production of oxaloacetate? Pyruvate carboxylase The process of ketogenesis refers to the conversion of acetyl CoA to which of the following compounds? β-hydroxybutyrate The transport of newly synthesized fatty acids to the adipose requires all of the following except: A. Interaction of ApoCII with lipoprotein lipase B. Transport of triacylglycerols from the liver using VLDLs C. Synthesis of triacylglycerol using glycerol 3-phosphate D. Carnitine to shuttle the fatty acids out of the mitochondria Carnitine to shuttle the fatty acids out of the mitochondria In the case of a deficiency of biotin, which of the following enzymes required for fatty acid synthesis will be impaired? Acetyl CoA carboxylase Which of the following compounds is the substrate for the synthesis of coritsol? A. Cholesterol B. Free fatty acids C. Glucose D. Amino acids Cholesterol Under cellular conditions when cholesterol is low, which of the following is a true statement regarding the sterol response element binding protein ? It will be associated with the the sterol response element (SRE) in the DNA HDL particles are characterized by the presence of which apoprotein: A. Apo B 100 B. Apo B48 C. ApoA D. ApoCII ApoA Which of the following is the regulatory enzyme in cholesterol synthesis? A. Carnitine palmitoyl transferase I B. HMGCoA reductase C. Acetyl CoA carboxylase D. HMGCoA synthase HMGCoA reductase Which of the following lipoproteins is responsible for the transport of cholesterol to peripheral tissues? A. VLDL B. HDL C. LDL LDL Which of the following enzymes is responsible for moving cholesterol from HDL to VLDL? A. Cholesterol esterase transfer protein (CETP) B. ABCA1 C. ApoB100 D. Lipoprotein lipase (LPL) Cholesterol esterase transfer protein (CETP) Secondary bile salts are generated by bacterial modification of primary bile salts in the intestinal lumen. These modification have which of the following impacts on bile salt solubility? A. decrease solubility B. increase solubility C. have no change on solubility decrease solubility The uptake of LDL increases intracellular cholesterol levels. This has which of the following impacts on de novo cholesterol synthesis? A. Increases activity of HMGCoA reductase B. Increases degradation of HMGCoA reductase C. Dephosphorylation of HMGCoA reductase. D. Increases movement of SREBP:SCAP to the golgi Increases degradation of HMGCoA reductase LCAT esterifies cholesterol. This process is required for which of the following processes? A. To trap cholesterol in HDL particles B. Movement of cholesterol out of the cell C. Degradation of cholesterol D. Synthesis of cholesterol derivatives To trap cholesterol in HDL particles A deficiency in the LDL receptor will result in which of the following? A. A decrease in intracellular cholesterol B. A decrease in circulating LDLs C. An decrease in de novo cholesterol synthesis D. A decrease in fatty acid synthesis A decrease in intracellular cholesterol Which of the following terms is used to define macrophages that are filled with oxLDL? A. Foam cells B. LDL C. Oxidized endothelial cell D. Endothelial cell foam cells Which of the following is a true statement, concerning HMGCoA reductase? A. It is regulated by covalent modification of a serine in its active site. B. It catalyzes the first committed step in cholesterol biosynthesis. C. It facilitates the production of NADPH.