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INTERPRET THE DATA Phosphofructokinase is an enzyme that acts on fructose 6-phosphate at an early step in glucose breakdown. Regulation of this enzyme controls whether the sugar will continue on in the glycolytic pathway. Considering this graph, under which condition is phosphofructokinase more active? Given what you know about glycolysis and regulation of
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- Can someone explain the answer to this ptoblem and why binding would not activate the enzyme?arrow_forwardCellular respiration connects the degradation of glucose to the formation of ATP, NADH and FADH2 in a series of 24 enzymatic reactions. Describe the major benefit of breaking down glucose over so many individual steps and describe the main role of NADH and FADH2arrow_forwardDiscuss the logic of the nature of the allosteric inhibitors and activators of glycolysis. Why would these molecules be used?arrow_forward
- In hepatocytes, the enzyme glucokinase catalyzes the ATP-coupled phosphorylation of glucose. Glucokinase binds both ATP and glucose, forming a glucose-ATP-enzyme complex. The enzyme then transfers the phosphoryl group directly from ATP to glucose. Select the advantages of phosphoryl group transfer compared to hydrolysis and subsequent phosphorylation? ATP hydrolysis is thermodynamically unfavorable compared to group transfer. Glucokinase increases the transition state energy, favoring glucose phosphorylation. The process takes advantage of the high phosphoryl group transfer potential of ATP. Reaction intermediates do not need to be present in excess. Incorrectarrow_forwardIn glycolysis, the KM value of hexoquinase is 0.04 mM. At physiological conditions, the cellular concentration of glucose is between 4 mM to 15 mM. According with this information, which of the following statements is true (Choose all that are correct) The enzyme has a low affinity for its substrate The enzme is working at its maximum velocity The phosphorilation of glucose is very slow The small value of KM assures that glycolysis will continue even when the concentration of glucose drops below 4 mM. The hexoquinase is saturated with glucosearrow_forwardThe following Michaelis-Menten plot shows the response of phosphofructokinase-1 (PFK-1), an enzyme in the glycolytic pathway, to the presence of ATP and AMP. Based on the data below, which of the following statements apply? Select all that apply. No inhibitors (low (ATP)) 1 mM ATP + 0.1 mM AMP 1 mM ATP 1.0 2.0 (Fructose-6-phosphate) mM Fig. : Regulation of PFK activity AMP is an allosteric modifier that enhances the binding of the substrate fructose 6-phosphate а. O b. AMP is an allosteric modifier that reduces the binding of the substrate fructose 6-phosphate ATP is an allosteric modifier that reduces the binding of the substrate fructose 6-phosphate O c. O d. ATP is an allosteric modifier that enhances the binding of the substrate fructose 6-phosphate Phosphofructokinase activityarrow_forward
- The metabolic pathway responsible for clearing lactic acid from our bodies is called the Cori Cycle. It occurs in the liver, and converts lactic acid back into pyruvic acid, and then into glucose. The glucose can then be used for energy metabolism again. However, the Cori Cycle requires a net input of 4 ATP to operate. Based on this information how can you describe the Cori Cycle? [Select any/all that apply.] Cori Cycle is exergonic. Cori Cycle is anabolc. Cori Cycle is catabolic. Cori Cycle is endergonic.arrow_forwardAntagonist binds to the enzyme at a site far away from the receptor site to inhibit the function of an enzyme. Select one: O True O False Glycolysis is a reductive process because glucose is reduced to form pyruvate. Select one: O True O False Hexokinase catalyses an irreversible reaction in glycolysis. Select one: O True O Falsearrow_forwardDetermine the ATP production of glucose catabolism by glycolysis and Krebs Cycle using the following information: 1. Glycolysis: Net 2 ATP, 2 NADH + H+2. Pyruvate --> acetyl CoA: Produces 2 NADH + H+/glucose3. Krebs Cycle --> 2 FADH2 + 2 ATP + 6 NADH + H+/glucose 2.5 ATP are produced/NADH + H+ delivered electron to the electron transport system1.5 ATP are produced/FADH2 delivered electron to the electron transport systemarrow_forward
- Define and describe the steady-state in metabolism using glycolysis as your example. Your answer should include idea of how a pathway is pushed in a specific direction and how the pathway could adapt to a changing environment to maintain the steady-state.arrow_forwardUnlike a rabbit, running all-out for a few moments to escape a predator, migratory birds require energy for extended periods of time. For example, ducks generally fly several thousand miles during their annual migration. The flight muscles of migratory birds have a high oxidative capacity and obtain the necessary ATP through the oxidation of acetyl-CoA (obtained from fats) via the citric acid cycle. Compare the regulation of muscle glycolysis during short-term intense activity, as in a fleeing rabbit, and during extended activity, as in the migrating duck. Why must the regulation in these two settings be different? Extended activity requires the highly efficient anaerobic metabolism of fats, rather than the less efficient aerobic metabolism of glucose. Extended activity requires the highly efficient aerobic oxidation of fats, rather than the less efficient anaerobic metabolism of glucose. Extended activity stimulates glycolysis because the concentrations of citrate and acetyl-CoA are…arrow_forwardThe energy for the production of ATP comes from the breakdown of a glucose molecule via many enzyme-mediated chemical reactions occurring at several distinct stages of cellular respiration. During this time, the chemical energy stored in glucose is continually trans- ferred across these reactions. Which of the following describes the form in which most of the energy from the glucose molecule is stored just before the oxidative phosphorylation stage in aerobic cellular respiration? A B с D acetyl CoA FADH 2 NADH pyruvatearrow_forward
- Human Physiology: From Cells to Systems (MindTap ...BiologyISBN:9781285866932Author:Lauralee SherwoodPublisher:Cengage Learning