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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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- 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? Glucokinase increases the transition state energy, favoring glucose phosphorylation. Reaction intermediates do not need to be present in excess. The process takes advantage of the high phosphoryl group transfer potential of ATP. ATP hydrolysis is thermodynamically unfavorable compared to group transfer.arrow_forwardCan 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_forward
- The researchers did not study the effects of NADH, ADP and ATP on the enzyme. Given what you know of their roles in GAPDH, classify each as an activator or an inhibitor of the enzyme. What overall consideration having to do with how glycolysis is regulated allowed you to make these inferences, without having any data? Would ADP, a reactant of the phosphorylating pathway, tend to inhibit the competing non-phosphorylating pathway in order to get more ATP made? And the opposite for ATP whose presence indicates that pathway may not be needed any more?arrow_forwardDiscuss the logic of the nature of the allosteric inhibitors and activators of glycolysis. Why would these molecules be used?arrow_forwardDigestion of cellobiose in cows produces two glucose units which is then absorbed into the bloodand distributed into the cells for energy production. One glucose unit is catabolized in the muscle cellwhile the other is in the heart cell, to CO2 and H2O in the cellular respiration process. How many ATPmolecules are released? Please show your detailed computation.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_forwardCalculate the ATP yield when glucose is catabolized completely to six CO2 by a eukaryotic microbe. How does this value compare to the ATP yield observed for a bacterium? Suppose a bacterium used the Entner-Doudoroff pathway to degrade glucose to pyruvate and then completed the catabolism of glucose via the TCA cycle. How would this affect the total maximum ATP yield? Explain your reasoning.arrow_forward
- The 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_forwardThe 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_forward
- Human Physiology: From Cells to Systems (MindTap ...BiologyISBN:9781285866932Author:Lauralee SherwoodPublisher:Cengage Learning