UNE Medical Biochemistry Midterm Exam Review

UNE Medical Biochemistry Midterm Exam Review Ribose and NADPH - answerA family presents for genetic counseling. The couple has two female children who are alive and well; however, their infant son recently died in the nursery with severe hemolysis (lysis of red blood cells) and jaundice. The wife recalls she lost a brother in infancy with severe hemolysis, induced after a viral infection. The physician suspects a glucose-6-phosphate dehydrogenase deficiency, this would result in a deficiency in which of the following compounds in red blood cells? Transketolase - answerA patient presents to the emergency department with lactic acidosis. A deficiency in thiamine (TPP) is suspected and this will be consistent with a decrease in the activity of following enzymes? UDP-Glucose - answerGalactose 1-phosphate is initially converted to glucose 1-phosphate and requires which of the following compounds? Thiamine diphosphate - answerWhich of the following cofactors is required for transketolase activity? Glyceraldehyde 3-phosphate - answerAldolase B facilities a reaction that cleaves fructose 1- phosphate into two 3-carbon molecules that will enter glycolysis as which of the following compounds? Glycolysis - answerHigh levels of activity of the non-oxidative portion of the pentose phosphate pathway will directly produce intermediates of which of the following pathways? Glucose 6-phosphate dehydrogenase - answerThe major regulatory step of the pentose phosphate pathway is catalyzed by which enzyme? VLDL particles - answerInsulin stimulates fatty acid synthesis in the liver. These fatty acids are transported to the adipose tissue as which of the following? Free fatty acids - answerA young woman goes to work without eating breakfast and skips lunch. In this scenario, which of the following pathways is providing substrates used to generate ATP in the liver? Glucagon - answerCaffeine is a natural inhibitor of phosphodiesterase. If you were to consume a large amount of coffee you would likely see a prolonged response to which of the following stimulants or hormones? They enhance transcription when bound to receptors - answerA teenage female presenting with lack of menstruation (amenorrhea) is found to have a dysfunctional steroid receptor characteristic of androgen insensitivity syndrome. Which of the following statements accurately describes steroid hormones? Intracellular receptors - answerSteroid hormones bind which of the following types of receptors? They are specific to a chemical messenger - answerWhich of the following is a characteristic of all receptors? Free fatty acids - answerWhat is the primary oxidized fuel for skeletal muscle in the fasted state? Cyclic-AMP response element binding protein (CREB) - answercAMP elicits multiple cellular responses. The effects of cAMP on gene transcription are directly mediated by which of the following DNA binding proteins? GLUT4 - answerAn individual is recently diagnosed with Type 2 diabetes. In this individual, hyperglycemia may in part be due to inactivity of which of the following glucose transporters on skeletal muscle? Adenylyl cyclase - answerGlycogen degradation in the liver can be enhanced by elevated glucagon and the activation of a Gαs receptor. The initial step in this cascade involves which of the following second messengers or active enzymes? 2 - answerWhich of the following combinations of compounds is required to fully activate pyruvate carboxylase (+ indicates compound is necessary; - indicates compound is not necessary)? 1. Biotin + Acetyl-CoA + Oxaloacetate + Malate - 2. Biotin + Acetyl-CoA + Oxaloacetate - Malate - 3. Biotin - Acetyl-CoA + Oxaloacetate + Malate + 4. Biotin - Acetyl-CoA - Oxaloacetate + Malate + Acetyl-CoA - answerWhich of the following compounds is not a substrate for gluconeogenesis?