Homework 8 Questions PDF

Homework 8 Questions 1. In the induced fit mechanism for hexokinase, the amino acids in the active site are not correctly positioned to catalyze the reaction until after _________________ binds. ATP glucose & glucose 6-phosphate ADP 2. Triose phosphate isomerase deficiency is caused by mutations tha...

Homework 8 Questions 1. In the induced fit mechanism for hexokinase, the amino acids in the active site are not correctly positioned to catalyze the reaction until after _________________ binds. ATP glucose & glucose 6-phosphate ADP 2. Triose phosphate isomerase deficiency is caused by mutations that result in an impaired or non-functional triose phosphate isomerase enzyme. Non-functional triose phosphate isomerase would result in ______________________ (increased, decreased or unchanged) production of ATP and _____________________ (increased, decreased or unchanged) production of NADH in glycolysis. 3. In the reaction catalyzed by glyceraldehyde 3-phosphate dehydrogenase an energetically unfavorable reaction intermediate is & formed, increasing the activation energy barrier in the second part of the reaction. an & energetically unfavorable reaction intermediate is formed, decreasing the activation energy barrier in the second part of the reaction. an energetically favorable reaction intermediate is & formed, increasing the activation energy barrier in the second part of the reaction. & an energetically favorable reaction intermediate is formed, decreasing the activation energy barrier in the second part of the reaction. 4. A high phosphoryl transfer potential compound is a molecule that has a very positive ΔG°ʹ value for giving up a & phosphate, meaning it is very energetically favorable for a phosphate to be removed from the molecule. & has a very positive ΔG°ʹ value for giving up a phosphate, meaning it is very energetically unfavorable for a phosphate to be removed from the molecule. has a very negative ΔG°ʹ value for giving up a phosphate, meaning it is very energetically favorable for a phosphate to be removed from the molecule. has a very negative ΔG°ʹ value for giving up a phosphate, meaning it is very energetically unfavorable for a phosphate to be removed from the molecule. O & 2 net ATP (produced minus invested) 5. A total of ______ molecules are produced in the conversion of one molecule of glucose to two molecules of pyruvate. (numerical answer) 6. Fermentation is necessary during anaerobic conditions because O NADH cannot give up its electrons to electron transport in the absence of oxygen. ATP cannot be formed by glycolysis in the absence of oxygen. & NAD cannot be converted to NADH in the absence of oxygen. pyruvate cannot accept electrons from NADH in the absence of oxygen. + 7. Lactic acid fermentation in muscle is only sustainable for a short amount of time because it utilizes large amounts of glucose, so it will quickly O deplete glucose in the cell. it utilizes small amounts of glucose, so it will not produce enough ATP to sustain repeated muscle contraction. 8. Red blood cells only use lactic acid fermentation for energy production because red blood cells are not able to take up oxygen. red blood cells do not have mitochondria. ↑ red blood cells have higher energy needs than most cells. red & blood cells do not have the enzyme glyceraldehyde 3-phosphate dehydrogenase. ⑳ 9. In the reaction catalyzed by the enzyme pyruvate carboxylase, the favorable free energy of ATP hydrolysis is used to form carboxyphosphate. The phosphate group from carboxyphosphate is transferred to biotin to form biotin-phosphate carboxyphosphate. The carboxyl group from carboxyphosphate is transferred to biotin to form carboxybiotin. bicarbonate. An H from bicarbonate is transferred to biotin to form biotinic acid. O & + & bicarbonate. The carboxyl group from bicarbonate is transferred to biotin to form carboxybiotin. 10. In the pyruvate carboxylase reaction, the substrate that binds to the active site in the carboxyl transferase (CT) domain is CO ATP HO pyruvate 2 G 2 11. Converting oxaloacetate to phosphoenolpyruvate requires an energetically favorable oxidation-reduction reaction to provide energy for an unfavorable acyl phosphate formation an energetically favorable decarboxylation and a phosphoryl transfer from GTP the transfer of a phosphate from 1,3bisphosphoglycerate, which has a higher phosphoryl transfer potential than phosphoenolpyruvate. the transfer of a phosphate from glucose 6-phosphate, which has a lower phosphoryl transfer potential than phosphoenolpyruvate. O Use the following reaction to answer questions 12 and 13: 12. The above reaction is catalyzed by the enzyme hexokinase phosphofructokinase (PFK) glucose 6-phosphatase O fructose 1,6-bisphosphatase 13. In the liver, this reaction is part of glycolysis, but not gluconeogenesis & gluconeogenesis, but not glycolysis both glycolysis and gluconeogenesis Use the following reaction to answer questions 14 and 15: 14. The above reaction is catalyzed by the enzyme phosphoglucose isomerase aldolase O phosphoglycerate mutase enolase 15. In the liver, this reaction is part of glycolysis, but not gluconeogenesis gluconeogenesis, but not glycolysis both glycolysis and gluconeogenesis O 16. Having glucose 6-phosphatase located in the endoplasmic reticulum (ER) prevents glucose 6-phosphate being converted to glucose except when glucose is needed for the bloodstream because transporters in the ER membrane will not bring glucose 6-phosphate into the ER unless it is being produced by pathways that provide glucose for the bloodstream. glucose is not needed for the bloodstream because transporters in the ER membrane will not bring glucose into the ER unless there is a very high glucose concentration in the cytoplasm. glucose is needed for the bloodstream because there is a specialized allosteric effector in the ER that upregulates glucose 6-phosphatase. glucose is not needed for the bloodstream because there is a specialized allosteric effector in the ER that downregulates glucose 6-phosphatase. & 6 ATP equivalents (total ATP + GTP 17. A total of ______ molecules) are required to produce one molecule of glucose from two molecules of pyruvate. (numerical answer) 18. The lactate produced in lactic acid fermentation will be transported through the bloodstream to the liver and will be used to produce alanine for protein synthesis. to the liver and will be used to produce glucose for the G bloodstream. to skeletal muscle cells and will be used to produce alanine for protein synthesis. to skeletal muscle cells and will be used to produce glucose for the bloodstream. 19. Upload your answers in case there is an error in the Canvas automatic grading.