Glucose is phosphorylated to glucose-6-phosphate by hexokinase in the first step of the glycolytic pathway to trapit in the cell, as G6P cannot diffuse across the lipid bilayer. This reaction also decreases the concentration of freeglucose, favoring additional import of the molecule. However, this has a postive standard free energy of 3 kcal permole. To favor this reaction, hydrolysis of ATP is coupled, which has a standard free energy of -7 kcal per mole.Determine the actual free energy change in kcal/mole for the following conditions:Glucose concentration: 4.5 mMATP conc: 3.79 mMG6P conc. 0.052 mMADP conc: 0.12 mMinorganic phosphate conc: 1.3 mMtemperature: 313 KAns. in 3 SFs.

Reactions that have a positive value of Delta G are not favorable in nature. Hence in order to…

Answered: Glucose is phosphorylated to…

Biochemistry

6th Edition

ISBN:9781305577206

Author:Reginald H. Garrett, Charles M. Grisham

Publisher:Reginald H. Garrett, Charles M. Grisham

Chapter27: Metabolic Integration And Organ Specialization

Section: Chapter Questions

Problem 20P: Figure 27.3 illustrates the response of R (ATP-regenerating) and U (ATP-utilizing) enzymes to energy...

See similar textbooks

Similar questions

Intramitochondrial ATP concentrations are about 5 mM, and phosphate concentration is about 10 mM. If ADP is five times more abundant than AMP,calculate the molar concentrations of ADP and AMP at an energy charge of 0.85. Calculate ∆G for ATP hydrolysis at 37 °C under these conditions.The energy charge is the concentration of ATP plus half the concentration of ADP divided by the total adenine nucleotide concentration.
Step 4 of the pentose phosphate pathway converts ribulose-5-phosphate to ribose-5-phosphate. Which glycolytic reaction does this reaction resemble and what type of enzyme catalyzes it?
AMP- PNP is a non-hydrolyzable ATP analog that cannot be metabolized by cells. Taurocholate is a bile acid that helps emulsify fats. When taurocholate is added to hepatocyte cell culture, it accumulates in those cells. The graph below shows the rate of cellular accumulation of the drug taurocholate in the presence of either ATP, ATP, or AMP-PNP. Based on this date, describe the mechanism by which taurocholate enters the cell. Justify the answer.
The formation of glutamine from glutamate and ammonium ions requires 14.2 kJ mol-1 of energy input. It is driven by the hydrolysis of ATP to ADP mediated by the enzyme glutamine synthetase. {a) Given that the change in Gibbs energy for the hydrolysis of ATP corresponds to ΔG = -31 kJ mol-1, under the conditions prevailing in a typical cell , can the hydrolysis drive the formation of glutamine? (b) What amount {in moles) of ATP must be hydrolysed to form 1 mol glutamine? (c) Suppose that the radius of a typical cell is 10 μm and that inside it 106 ATP molecules are hydrolysed each second. What is the power density of the cell in watts per cubic metre (1W = 1 Js- 1)? (d) A computer battery delivers about 15 Wand has a volume of 100 cm3 Which has the greater power density, the biological cell or the battery?
The malate–aspartate shuttle yields about2.5 moles of ATP for each mole of cytosolic NADH. Why doesnature use the glycerol–phosphate shuttle, which yields only about1.5 moles of ATP?
Hexokinase catalyzes the first step of glycolysis, in which glucose is phosphorylated to form glucose‑6‑phosphate. Give two reasons why a Mg2+ cation is required to facilitate this reaction.
The phosphorylation and oxidative decarboxylation of oxaloacetate by inorganic phosphate (Pi) to make phosphoenolpyruvate and carbon dioxide is endergonic under intracellular conditions. It is characterized by this equation: Oxaloacetate + Pi ←→ Phosphoenolpyruvate + H2O + CO2 ΔG’ = +24.6 kJ/mol The synthesis of GTP from GDP and inorganic phosphate (Pi) in solution is endergonic under intracellular conditions, and it is characterized by this equation: GDP + Pi ←→ GTP + H2O ΔG’ = +30.5 kJ/mol Write a new net thermodynamically coupled reaction equation that describes the synthesis of phosphoenolpyruvate from oxaloacetate using the hydrolysis of GTP to power the reaction and calculate the new net ΔG’ of this reaction. Show all of your work.
The active site of an enzyme that uses a general acid-base catalytic mechanism contains a Glu and an Asp residue (both of which are essential for catalysis) with pKa values of 5.9 and 4.5, respectively. If the enzyme is found in the lysosome (pH = 5.2), which residue will act as the general acid and which will act as the general base during the initial steps of the reaction?
If glucokinase has a higher Km for glucose than does hexokinase, but can only bind to D-glucose, while hexokinase can bind to several hexose sugars (like D-glucose, D-mannose, and D-fructose), then: glucokinase has both a higher affinity and a higher specificity for D-glucose than does hexokinase glucokinase has both a lower affinity and a lower specificity for D-glucose than does hexokinase glucokinase has a higher affinity but a lower specificity for D-glucose than does hexokinase glucokinase has a lower affinity but a higher specificity for D-glucose than does hexokinase all of the above
How many molecules of ATP are produced from the complete metabolism of 2.12g of triacylglycerol containing two stearic acid chains and one palmitic acid chain? Assume that all electrons of cytosolic NADH are transferred through the dihydroxyacetone phosphate/glycerol 3-phosphate shuttle
In 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 glucose
Glucose is converted to pyruvate in glycolysis, yielding a netsynthesis of 2 ATP. In certain cells pyruvate can be reconverted to glucose during gluconeogenesis. How many ATPsare required to convert pyruvate back to glucose?

SEE MORE QUESTIONS

Recommended textbooks for you

Biochemistry

ISBN:

9781305577206

Author:

Reginald H. Garrett, Charles M. Grisham

Publisher:

Cengage Learning

Biochemistry

ISBN:

9781305577206

Author:

Reginald H. Garrett, Charles M. Grisham

Publisher:

Cengage Learning

SEE MORE TEXTBOOKS