UNE Medical Biochem Final Exam Review Rated 100% Correct!!

UNE Medical Biochem Final Exam Review Rated 100% Correct!! short chain fatty acids and medium chain fatty acids enter mitochondria by: Diffusion Under fasting conditions (ratio of insulin to glucagon 1), elevated glucagon will activate which of the following enzymes? Hormone sensitive lipase the process of ketogenesis refers to the conversion of acetyl-CoA to which of the following compounds? B-hydroxybutyrate A well, 2-year-old female presents to the clinic with symptoms of a viral illness. She had vomiting and diarrhea, weak, hypoglycemic, elevated liver enzymes, NO KETONES in urine. Laboratory analysis shows elevated medium chain fatty acylcarnitines in blood....which abnormality is the likely diagnosis for the child? Defect of medium chain coenzyme A dehydrogenase Ketonuria, hyperglycemia and severe acidosis are diagnostic indicators of the presentation of type 1 diabetic ketoacidosis. Which of the following compounds are ketone bodies that would be elevated in serum and urine from a patient in this condition? B-hydroxybutyrate and aceotoacetate Which of the following shuttle systems is necessary for the oxidation of long chain fatty acids? carnitine B-oxidation of long chain fatty acids is inhibited by: Malonyl-CoA An 11-year-old female...thirsty, frequent urination...thin, in the 30th percentile for height and weight....glucose in urine. Evaluation of bloodwork would reveal decreased levels of which of the following compounds or hormones? Insulin Malate can be converted to pyruvate in the cytosol. Which of the following compounds is directly generated in this conversion and is essential for fatty acid synthesis? NADPH Insulin stimulates lipogenesis through several mechanisms. Which of the following is not an insulin-stimulated process that enhances lipogenesis? Decreased activity of the pyruvate dehydrogenase complex Under conditions when glucose oxidation is elevated, the acetyl CoA produced will allosterically activate which of the following enzymes leading to an increase in production of oxaloacetate? pyruvate carboxylase An individual consumes a large meal consisting of a cheeseburger and fries. Which of the following intermediates is shuttled out of the TCA cycle to be used as a substrate for fatty acid synthesis? citrate Fatty acid synthesis is a multimeric enzyme complex. Which of the following subunits contains pantothenic acid as a cofactor? Acyl carrier protein (ACP) Under fasting conditions, acetyl CoA carboxylase will be inhibited by an increase in which of the following compounds? Fatty acyl-CoA The de novo synthesis of fatty acid synthase enzyme complex results in the synthesis of: only palmitic acid (C16:0) Which of the following is the regulated step of lipogenesis in eukaryotes? Carboxylation of acetyl-CoA Which of the following best describes the role of HDL particles? HDL particles are required for the transport of cholesterol prom peripheral tissues to the liver Which of the following lipoproteins illustrated below is most consistent with an LDL? 3 Analysis of a patient's serum revealed elevated VLDL levels. Which one of the following mechanisms could account for this observation? Decreased activity of lipoprotein lipase A 6-year-old male is brought to PCP. Recent decline in schoolwork, low plasma LDL. This presentation would be consistent with a loss of which of the following apoproteins? ApoB100 A 12-year-old male is brought to PCP. Persistent blurred vision, xanthomas are noted, laboratory testing reveals extremely low plasma HDL. This presentation would be consistent with a loss of which of the following apoprotein? ApoA Nascent chylomicrons are synthesized in which of the following organs? Intestine Which of the following is the major source of extracellular cholesterol for human tissue? LDLs Which lipoprotein is responsible for the process of reverse cholesterol transport (the movement of cholesterol from the peripheral tissues back to the liver)? HDL Secondary bile salts are generated by bacterial modification of primary bile salts in the intestinal lumen. These modifications have which of the following impacts on bile salt solubility? Decrease solubility Which of the following best describes the primary role of bile salts during the digestive process? They are used for the emulsification of dietary lipids Under fasted conditions, (glucagon is elevated), which of the following enzymes will be phosphorylated and inactive? HMG-CoA reductase Which of the following best describes the mechanism by which cholesterol is eliminated? Cholesterol is used to synthesize secondary bile acids that are eliminated in the feces. When an LDL particle is taken up by the cell, what impact will this have on the regulation of de novo cholesterol synthesis? SREBP will be inhibited by Inside in the endoplasmic reticulum 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 A deficiency in the LDL receptor will result in an initial decrease in which of the following? Intracellular cholesterol The LDL receptor is also highly regulated in the cell. Which of the following proteins targets the LDL receptor for degradation? Proprotein converts subtilisin/kexin type 9 (PSK9) A 10-year-old female presents with chest pain, xanthomas, father MI, mother high cholesterol, heterozygous FH in parents, homozygous FH in patient. This disease results from mutations in the receptor for LDL... Which of the following apoproteins might be mutated? B100 A patient's triglyceride levels are within normal limits, but their cholesterol is 350 (normal 200). Physician prescribes medicine that inhibits the enzyme HMG CoA reductase. The drug that was prescribed lowers circulating levels of cholesterol by: Decreasing hepatic cholesterol biosynthesis Elevated cholesterol can enhance bile acid synthesis through which of the following mechanisms? increasing the activity of 7-a-hydroxylase HMG CoA reductase is highly regulated within the cell. Which of the following will reduce the activity of HMG-CoA reductase? Phosphorylation by an insulin-activated protein kinase In the event of a deficiency in ApoCII on VLDLs, which of the following processes would be impaired? Interaction of VLDL with lipoprotein lipase A deficiency in which of the following proteins will reduce cholesterol efflux from peripheral tissues to HDL particles? ABCG1 A 6-year-old male is brought to his PCP. Concerned with decline in schoolwork....has low plasma LDL....presentation is consistent with a loss of which of the following apoproteins? ApoA Which lipoprotein is responsible for the process of reverse cholesterol transport (the movement of cholesterol from the peripheral tissues back to the liver)? HDL Nascent chylomicrons are synthesized in which of the following organs? intestine