Glycolysis, Gluconeogenesis, and Glycogen Metabolism Published on August 30, 2020 by ehudspeth Glycolysis & Gluconeogenesis Von Gierke disease, is the most common of the glycogen storage diseases. This genetic disease impairs the ability of the liver to produce free glucose from glycogen and from gluconeogenesis. A deficiency in which of the following enzymes would lead to this disease? PEPCK Glucose-6 Phosphatase Pyruvate carboxylase deficiency PFK-1 2,3-BPG mutase Angel waddles into class one morning complaining of intense bum soreness that she says is from her CrossFit “workout” the previous evening. This soreness is in part due to the accumulation of lactate. Which of the following best explains the reasoning for why there is an accumulation of lactate during heavy intense exercise? Lack of oxygen availability Pyruvate is being generated at a higher rate than it can enter the TCA cycle Lactate is necessary to perform Gluconeogenesis The TCA cycle is inhibited by heavy intense exercise The Ca2+ produced from muscle contraction works to upregulate Lactate DH Which of the following enzymes is involved in a reaction unique to gluconeogenesis? Phosphoglucose isomerase Phosphoglyceromutase Pyruvate carboxylase Phosphofructokinase-1 Phosphoglycerate kinase Which enzyme in carbohydrate metabolism works as a tight control point for both the anabolic and catabolic pathways, ensuring that glycolysis and gluconeogenesis are not both active at the same time? FBPase-1 PFK-2 G-6-Pase Pyruvate carboxylase Phosphoglucomutase For a combination of reasons, high consumption of alcohol leads to a depletion of which carbohydrate metabolite? Pyruvate Glycogenin Oxaloacetate 3-phosphoglycerate 1,2-bisphosphoglycerate What is TRUE about fructose metabolism? It’s the most efficient fuel source for ATP Conversion of fructose-1 phosphate to fat is a highly regulated process Fructose enters glycolysis after the key regulatory step, allowing it to go unchecked and produce an abundance of fat in the liver Regulation of fructose is accomplished by PFK-2, which converts fructose 1-phosphate into fructose 2,6-bisphosphate The relatively high ratio of glucose to fructose in high fructose corn syrup is what makes the substance so bad for you Which of the following regulators when present will decrease or inhibit the formation of Acetyl CoA from Pyruvate by activating PDC Kinase? Calcium ADP Pyruvate NADH NAD+ The conversion of Fructose-6-Phosphate to Fructose-1,6-Bisphosphate is a highly regulated part of glycolysis. Which of the following is an agonist of this step? cAMP ATP Fructose-2,6-bisphosphate Fructose-1,6-bisphosphate Citrate Which of the following pairs would show a similar Lineweaver-Burke graph? Hexokinase, GLUT 2 Glucokinase, GLUT 2 Hexokinase, GLUT 4 Glucokinase, GLUT 4 Glucokinase, SGLT Which step in glycolysis is unable to proceed if there is a shortage of NAD+? Step 1 – glucose → glucose-6-phosphate Step 3 – fructose-6-phosphate → fructose-2,6-bisphosphate Step 6 – glyceraldehyde-3-phosphate → 1,3-bisphosphoglycerate Step 9 – 2-phosphoglycerate → phosphoenolpyruvate Step 10 – phosphoenolpyruvate → pyruvate Which of the following is required to produce additional NADPH in order to fuel Glutathione Reductase to reduce glutathione? NAD+ FAD Glucose-6-phosphate Ribose-6-phosphate Selenium Which of the following is most characteristic of Glycolysis? Increased FBP-1 activity Phosphorylated (PFK-2/FBP-2) enzyme PFK-1 product modulating Pyruvate Kinase activity Increased FBP-2 activity Decreased PFK-1 activity A mutation in PFKFB genes 1-4 on chromosome X leads to non-functional PFK-2/FBP-2 enzyme. What effect does this have on metabolism? Inability to carry out glycolysis because fructose-1,6-bisphosphate cannot be synthesized from fructose-6-phosphate. Inability to metabolize fructose. Inability to carry out glycolysis because fructose-2,6-bisphosphate is necessary for the activity of PFK-1/FBPase-1 Simultaneous gluconeogenesis and glycolysis Time is Up!
