phosphofructokinase reaction ofFructose-2,6-bisphosphate is a regulator of both glycolysis and gluconeogenesis for theglycolysis and the fructose-1,6-bisphosphatase reaction of gluconeogenesis. In turn, the concentration offructose-2,6-bisphosphate is regulated by many hormones, second messengers, and enzymes.Classify each condition according to its effect on glycolysis and gluconeogenesisActivates glycolysis and inhibits gluconeogenesisactivation of PFK-2increased levels of cAMPActivates gluconeogenesis and inhibits glycolysisincreased levels of fructose-2,6-bisphosphateactivation of fructose-2,6-bisphosphatase (FBPase-2)increased glucagon levels

Activates glycolysis and inhibits gluconeogenesis:Increased levels of…

Answered: phosphofructokinase reaction of…

Biochemistry

9th Edition

ISBN:9781319114671

Author:Lubert Stryer, Jeremy M. Berg, John L. Tymoczko, Gregory J. Gatto Jr.

Publisher:Lubert Stryer, Jeremy M. Berg, John L. Tymoczko, Gregory J. Gatto Jr.

Chapter1: Biochemistry: An Evolving Science

Section: Chapter Questions

Problem 1P

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Similar questions

Fourteen NADPH molecules are required to produce one molecules of palmitic acid from acetyl CoA. Substantiate this statement by referring to the enzymatic activities involved in reduction steps during fatty acid synthesis and the number of cycles required to produce palmitic acid from acetyl CoA. How many molecules of ATP is required for the synthesis of palmitic acid from cytosolic acetyl-CoA?
Mention two biological advantages to an organism that stores its carbohydrate reserves as starch or glycogen rather than as an equivalent amount of free glucose. What role does the protein, glycogenin play in glycogen synthesis? Name the reactants and products of the first two steps of the gluconeogenesis pathway if pyruvate is used as the starting material (structures not needed). Explain why people with a deficiency of the enzyme glucose 6-phosphate dehydrogenase (G6PDH) suffer from hemolytic anemia What is meant by reciprocal regulation? Name one compound that reciprocally regulates glycolysis and gluconeogenesis pathways. Which enzymes are regulated by this compound? What reactions are catalyzed by these enzymes?
Considering the evidence that led Krebs to propose a cyclic pathway for oxidation of pyruvate, discuss the type of experimental evidence that might have led to realization of the cycdic nature of the glyoxy- late pathway.
Indicate what will happen (increase, decrease or no effect) to the activity of the enzyme or rate of the metabolic pathway given the following conditions.
For each of the following situations, predict the major concequences for glycogen metabolism. Explain your logic in a few sentences. Will the amount of glycogen be higher or lower than the normal or unchanged. a) Effect of mutation Y194F in glycogenenin on glycogen synthesis. b) Effect on the loss of the gene that encodes inhibitor I of protein phosphatase I on both glycogen phosphorylase and glycogen synthase. c) Effect on the substrate analog shown below in glycogen synthesis (hint: what is the normal reaction sequence? At which step in the pathway does this sequence become blocked and why?)
What is the quaternary structure of glycogen phosphorylase? How would you characterize the allosteric effects of its small molecule substrate? (one word) What allosteric model (mechanism) that you have learned does it seem to follow? (one acronym)
In the liver, fructose can be converted into glyceraldehyde 3- phosphate and dihydroxyacetone phosphate without passing through the phosphofructokinase-regulated reaction. Show the reactions that make this conversion possible. Why might ingesting high levels of fructose have deleterious physiological effects?
Starting with pyruvate (CH3COCOO—) as the precursor, the first step of gluconeogenesis is activation of pyruvate. Show the reaction for activation of pyruvate. Name the enzyme and coenzyme for this reaction. Why is the activation step necessary? What is the next step after the activation step?
Phosphoglucomutase is crucial for glycogen breakdown as well as for glycogen synthesis. Explain the role of this enzyme in each of the two processes.
In different organisms sucrose can be cleaved either by hydrolysis or by phosphorolysis. Calculate the ATP yield per mole of sucrose metabolized by anaerobic glycolysis starting with (a) hydrolytic cleavage and (b) phosphorolytic cleavage.
During glycolysis, the enzyme glyceraldehyde phosphate dehydrogenase (GAPDH) catalyzes the oxidation and phosphorylation of glyceraldehyde 3-phosphate, forming 1,3-bisphosphoglycerate. This reaction, shown below, has a ΔG that is close to zero under cellular conditions. During gluconeogenesis, GAPDH catalyzes the reverse reaction, in which 1,3-bisphosphoglycerate is reduced and dephosphorylated. Given this information, which of the following conditions are most likely to directly alter the relative rates of the forward and reverse reactions? (select two answers) changes in the relative concentrations of glyceraldehyde 3-phosphate and 1,3-bisphosphoglycerate changes in the relative concentrations of NAD+ and NADH decreased cellular concentration of pyruvate increased cellular concentration of glucose regulation of GAPDH activity
The oxidation of Gly-3-P to 1,3-bisphosphoglycerate proceeds with an unfavorable AG which equals 6.3 KJ/mol, yet the flow through this point in the glycolytic pathway proceeds smoothly. Why???

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