WGU C785 Lipid Metabolism and Disease

WGU C785 Lipid Metabolism and Disease Learning Objective ANS Given a clinical scenario/vignette (e.g., a patient suffering from ketoacidosis, MCADD, hypertriglyceridemia), the student will identify the impact a de ...

WGU C785 Lipid Metabolism and Disease Learning Objective ANS Given a clinical scenario/vignette (e.g., a patient suffering from ketoacidosis, MCADD, hypertriglyceridemia), the student will identify the impact a defect in lipid metabolism (e.g., cholesterol, ketone bodies) would have. (2 questions on the assessment) 1. Acetyl-CoA is the starting material used to make fatty acids. Fatty acid synthesis occurs in the cell cytosol but acetyl-CoA is produced in the mitochondria and cannot be transported across the mitochondrial membrane. How does the cell overcome this issue? ANS Acetyl-CoA is converted to citric acid for export out of the mitochondrion then reconverted to acetyl-CoA in the cytoplasm 2. Regulation of carbohydrate and fatty acid metabolism are connected. Both insulin and glucagon play a role in that regulation. Glucagon is released after fasting, when blood glucose is low, to stimulate glucose production and mobilize energy. Release of glucagon would decrease all of the following EXCEPT: ANS Glycogenolysis Glucagon stimulates glycogenolysis to release glucose for the liver to export to the bloodstream when blood sugar is low. 3. Which of the following contributes to the development of ketoacidosis in a diabetic patient? ANS Increased beta oxidation of fatty acids in the absence of insulin signalling In the absence of insulin, beta oxidation (fatty acid breakdown) will increase. Increased fatty acid breakdown leads to buildup of acetyl-CoA, which is used to make ketone bodies (ketogenesis). Excessive amounts of ketone bodies lower blood pH, which leads to diabetic ketoacidosis. 4. Fatty acid chains can range anywhere from 4 to 36 carbons. When enzymes that are specific for breaking down a particular length of fatty acid chain are defective, fatal diseases occur. Which of the following diseases is associated with failure to breakdown fatty acids? ANS MCADD (Medium-chain acyl-CoA dehydrogenase deficiency) MCADD is a disease that results from a defect in the beta oxidation of medium-chain fatty acids. MCADD usually presents in infants as vomiting and/or lack of energy due to their inability to utilize medium-chain fatty acids.