Question

The direct phosphorylation of glucose by inorganic phosphate is a thermodynamically unfavorable reaction: glucose+Pi→glucoseglucose+Pi→glucose-66-phosphate+H2Ophosphate+H2O ΔG∘′=+3.3kcal/molΔG∘′=+3.3kcal/mol In...

The direct phosphorylation of glucose by inorganic phosphate is a thermodynamically unfavorable reaction:

glucose+Pi→glucoseglucose+Pi→glucose-66-phosphate+H2Ophosphate+H2O
ΔG∘′=+3.3kcal/molΔG∘′=+3.3kcal/mol

In the cell, glucose phosphorylation is accomplished by coupling the reaction to the hydrolysis of ATPATP, a highly exergonic reaction:

ATP+H2O→ADP+PiATP+H2O→ADP+Pi
ΔG∘′=−7.3kcal/molΔG∘′=−7.3kcal/mol

Typical concentrations of these intermediates in yeast cells are as follows:
[glucose-6-phospate] = 0.08mMmM
[ATP]=1.8mM[ATP]=1.8mM
[Pi]=1.0mM[Pi]=1.0mM
[ADP]=0.15mM[ADP]=0.15mM
Assume a temperature of 25∘C∘C for all calculations.

What minimum concentration of glucose would have to be maintained in a yeast cell for the coupled reaction to be thermodynamically spontaneous?

Homework Answers

Answer #1

Minimum concentration of Glucose is 7.712 nM

Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
For the uncoupled and coupled reactions glucose + phosphate → glucose-6-phosphate, ΔG°' = +13.8 kJ/mol glucose...
For the uncoupled and coupled reactions glucose + phosphate → glucose-6-phosphate, ΔG°' = +13.8 kJ/mol glucose + ATP → glucose-6-phosphate + ADP, ΔG°' = -16.7 kJ/mol By how much does coupling to ATP increase the apparent equilibrium constant for the formation of glucose-6-phosphate? Given R = 8.315 J/mol · K. T = 298 K. a) 1.2 times b) 2.2 × 105 times c) 2.2 × 108 times d) 4.5 × 10-6 times
Many metabolic reactions are coupled reaction. Such as the first step in glycolysis drawn below: Glucose...
Many metabolic reactions are coupled reaction. Such as the first step in glycolysis drawn below: Glucose + Pi ↔ glucose-6-phosphate + H2O a. The ΔG°’ is 14 kJ•mol-1. What is the ratio of [G6P]/[glucose][Pi] at equilibrium at 25°C? b. The above reaction is coupled to the hydrolysis of ATP. In muscle cells at 37°C, the steady-state ratio of [ATP]/[ADP] is 12 & the ΔG°’ for ATP hydrolysis is -30.5 kJ•mol-1. Assuming that glucose and G6P achieve equilibrium values in muscle...
For the isomerization of glucose-1-phosphate to glucose-6-phosphate, the ΔG°′ = -7.28 (correct?). [Express your answer in...
For the isomerization of glucose-1-phosphate to glucose-6-phosphate, the ΔG°′ = -7.28 (correct?). [Express your answer in kJ/mol using 2 significant figures.] the tolerance is +/-2% At 37°C and concentrations of 5 mM glucose-6-phosphate and 0.1 mM glucose-1-phosphate, the ΔG = . [Express your answer in kJ/mol using 2 significant figures.] the tolerance is +/-2% Under these differing conditions, the isomerization of G1P to G6P is spontaneous under the 25C or 37C? Phosphoenolpyruvate Delta G = −61.9 1,3-Bisphosphoglycerate −49.4 ATP →...
The first step of glucose metabolism is the formation of glucose-6-phosphate. Under a certain condition, Glucose...
The first step of glucose metabolism is the formation of glucose-6-phosphate. Under a certain condition, Glucose + ATP ⇌ Glucose-6-phosphate + ADP ΔG = - 17 kJ/mol at the same condition, ATP + H2O ⇌ ADP + Pi ΔG = - 30 kJ.mol-1 Calculate the free energy change of the following reaction: Glucose + Pi ⇌ Glucose-6-phosphate Please explain it as well as possible... Please help me figure out why the answer is 13 Kj/Mol... I keep on getting confused...
The glycolytic reaction glyceraldehyde 3-phosphate + Pi → 1,3-bisposphoglycerate has a ΔG°′ of +6.3 kJ/mol. In...
The glycolytic reaction glyceraldehyde 3-phosphate + Pi → 1,3-bisposphoglycerate has a ΔG°′ of +6.3 kJ/mol. In cells however, it is coupled to the subsequent reaction: 1,3- bisposphoglycerate + ADP → ATP + 3-phosphoglycerate which for which G°’= –18.5 kJ/mol Calculate the free energy change for these two reactions if they are coupled together. This was also given if helpful: Abbreviations for cofactors such as NADH, ATP etc. are sufficient unless the specific structure for that molecule is requested. Otherwise use...
The glucose/glucose-6-phosphate substrate cycle involves distinct reactions of glycolysis and gluconeogenesis that interconvert these two metabolites....
The glucose/glucose-6-phosphate substrate cycle involves distinct reactions of glycolysis and gluconeogenesis that interconvert these two metabolites. Assume that under physiological conditions, [ATP]=[ADP] and [Pi]=1mM. Consider the following glycolytic reaction catalyzed by hexokinase: ATP+glucose⇌ADP+glucose−6−phosphateΔG∘′=−16.7kJ/mol Calculate the equilibrium constant (K) for this reaction at 298 K, From the equilibrium constant, calculate the maximum [glucose-6-phosphate]/[glucose] ratio that would exist under conditions where the reaction is still thermodynamically favorable. The reverse of this interconversion in gluconeogenesis is catalyzed by glucose-6-phosphatase: glucose−6−phosphate+H2O⇌glucose+PiΔG∘′=−13.8kJ/mol K= 262 for...
A) Fructose-6-phosphate is phosphorylated to fructose-(1-6)-bisphosphate as part of the glycolytic pathway. The phosphorylation of fructose-6-phosphate...
A) Fructose-6-phosphate is phosphorylated to fructose-(1-6)-bisphosphate as part of the glycolytic pathway. The phosphorylation of fructose-6-phosphate by phosphate is described by the following equation: Fructose-6-phosphate + Pi ↔Fructose-(1-6)-bisphosphate ∆G0’ = +47.7 kJ/mol Suppose that the phosphorylation of fructose-6-phosphate is coupled to the hydrolysis of ATP (-30.5 kJ/mol). What is the ∆G0’ for the coupled reaction? A -17.2 kJ/mol B +17.2 kJ/mol C +15.0 kJ/mol D -16.5 kJ/mol E +0.7 kJ/mol B) Using the answer in question #5 to calculate the...
Consider the reaction: Glucose + Pi = glocose 6-phosphate +H2O DG°´ = +3kcal/mol What is the...
Consider the reaction: Glucose + Pi = glocose 6-phosphate +H2O DG°´ = +3kcal/mol What is the equilibrium constant, K´eq, for this reaction? (Note: the concentration of water is ignored.) Does the positive DG°´ in the above reaction mean that the reaction can never go spontaneously from left to right?
In some cells glucose can be taken up by two different transport systems: facilitated diffusion and...
In some cells glucose can be taken up by two different transport systems: facilitated diffusion and glucose/proton symporter. a) Why is glucose not taken up by passive diffusion but by means of permeases? Describe the composition and structure of the permeases. b) Distinguish between facilitated diffusion and carbohydrate/proton symporter. The energy used to promote the active transport is the sum of the concentration-dependent energy (R∙T∙lnK) and the electrical work (z∙F∙ΔV). This process is usually linked directly or indirectly to ATP...
In some cells glucose can be taken up by two different transport systems: facilitated diffusion and...
In some cells glucose can be taken up by two different transport systems: facilitated diffusion and glucose/proton symporter. a) Why is glucose not taken up by passive diffusion but by means of permeases? Describe the composition and structure of the permeases. b) Distinguish between facilitated diffusion and carbohydrate/proton symporter. The energy used to promote the active transport is the sum of the concentration-dependent energy (R∙T∙lnK) and the electrical work (z∙F∙ΔV). This process is usually linked directly or indirectly to ATP...