Question

In: Biology

Why are two phosphate groups added to glucose in stage one of glycolysis? A) To destabilize...

Why are two phosphate groups added to glucose in stage one of glycolysis?

A) To destabilize the intermediates in stage one, making the stage two reactions more favorable.

B) To provide all of the phosphate for ATP synthesis during stage two.

C) To increase the net ATP produced from one glucose molecule.

D) To activate the enzymes in stage two.

Solutions

Expert Solution

Answer. (A)

Glycolysis

Glycolysis involves the breakdown of 1 molecule of glucose to form 2 molcules of pyruvate with the net release of 2 ATP.

First, an enzyme hexokinase phosphorylates the glucose molecule to form glucose 6-phosphate. This helps in trapping glucose within the cell as a cell does not have transporters for phosphorylated sugars.

This glucose 6-phosphate is coverted to fructose 6=phosphate by phosphohexose isomerase. The rationale behind this is to form a symmetrical molecule which upon breakdown would yiels 2 3 memebered molecules.

Another phosphate group is added by phosphofructokinase to form fructose 1,6-bisphosphate. This desatbilizes the molecule and so facilitates its breakdown to glyceraldehyde 3-phosphate and dihydroxyacetone phosphate.


Related Solutions

Why do all the intermediates in glycolysis contain phosphate groups?
Why do all the intermediates in glycolysis contain phosphate groups?
In glycolysis, a glucose-phosphate is transformed into a fructose-phosphate. Which of the following reasons provides the...
In glycolysis, a glucose-phosphate is transformed into a fructose-phosphate. Which of the following reasons provides the best chemical rationale for this transformation? Choose the best answer. A. It is not possible to break a molecule of glucose into two pieces but it is possible to break a molecule of fructose into two pieces. B. Glucose is not a high phosphotransfer potential molecule but fructose is a high phosphotransfer potential molecule. C. There are no enzymes to add phosphate groups to...
Explain, using electron-pushing arguments, why glycolysis must go through the Glucose 6-Phosphate to Fructose 6-Phosphate step...
Explain, using electron-pushing arguments, why glycolysis must go through the Glucose 6-Phosphate to Fructose 6-Phosphate step (i.e. a C1 aldehyde to a C2 ketone). Focus on the subsequent aldolase-catalysed reaction and explain why Glucose 1,6 bisphosphate would not be able to go through the aldolase reaction.
Hexokinase catalyzes the first step of glycolysis, in which glucose is phosphorylated to form glucose-6-phosphate. Which...
Hexokinase catalyzes the first step of glycolysis, in which glucose is phosphorylated to form glucose-6-phosphate. Which of the following statements are accurate? Choose all that apply. Hexokinase is found in the mitochondrial membrane. Hexokinase consists of two domains, or lobes, that come together when glucose and the MgATP2� complex are bound. Most kinases require the presence of a monovalent metal ion cofactor to prevent ATP hydrolysis. The conformational shift that occurs when glucose, but not water, enters the active site...
biochemisttry 2. (10 pts.) Hexokinase catalyzes the first reaction in glycolysis converting glucose to glucose 6-phosphate...
biochemisttry 2. (10 pts.) Hexokinase catalyzes the first reaction in glycolysis converting glucose to glucose 6-phosphate (G6P). This reaction, on its own (without the enzyme catalyst), has a ΔG’° = +13.8 kJ/mol, and is written as: Glucose + Pi → Glucose 6-phosphate + H2O The conversion of Glucose to G6P is dependent on the hydrolysis reaction of ATP to ADP, which has a ΔG’° = -30.5 kJ/mol, and is written as: ATP + H2O → ADP + Pi The overall...
The addition of phosphate groups to intermediate molecules in glycolysis results in: a. Increased potential energy...
The addition of phosphate groups to intermediate molecules in glycolysis results in: a. Increased potential energy of that intermediate molecule b. Use of ATP c. Subsequent generation of ATP via substrate-level phosphorylation d. Direct generation of ATP via oxidative phosphorylation e. A, B, and C are correct Which of the following statements regarding electron excitation in photosynthesis is correct? a. All forms of electromagnetic radiation are equally capable of generating free radicals b. All wavelengths of light induce equal degrees...
draw the mechanism for aldolase with glucose-6-phosphate that indicates why glucose-6-phosphate is not an appropriate substrate...
draw the mechanism for aldolase with glucose-6-phosphate that indicates why glucose-6-phosphate is not an appropriate substrate in terms of efficienty having a convergent pathway
Consider the following inter-conversion, which occurs in glycolysis: Fructose-6-phosphate ↔ Glucose-6-phosphate Keq’ = 1.97 What is...
Consider the following inter-conversion, which occurs in glycolysis: Fructose-6-phosphate ↔ Glucose-6-phosphate Keq’ = 1.97 What is ΔG°’ for the reaction (Keq’ measured at 25°C; and R=8.314 J•mol-1•K-1)? (b) If the concentration of fructose-6-phosphate is adjusted to 1.5 M and that of glucose- 6-phosphate is adjusted to 0.50 M, what is ΔG? (c) Why are ΔG°’ and ΔG different?
The hydrolysis of glucose-6- phosphate to give glucose plus phosphate has a ∆G o = -...
The hydrolysis of glucose-6- phosphate to give glucose plus phosphate has a ∆G o = - 3.3 kcal/mol. In the liver glucose concentrations are extremely high during the fed state because of the proximity of the liver to the portal vein, and thus hydrolysis should be unfavorable. What is ∆G for this hydrolysis reaction at 0.5 M glucose, 0.01 M phosphate and 10 -6 M for glucose-6- phosphate? (Assume 2.303RT = 1360 cal/mol.) A. -3460 cal/mol B. -1730 cal/mol C....
1) How many ATP molecules are consumed in the hexose stage of glycolysis for every one...
1) How many ATP molecules are consumed in the hexose stage of glycolysis for every one molecule of glucose? A) 0; ATP is produced, not consumed, by glycolysis. B) 1 C) 2 D) 3 E) 4 2) During glycolysis, isomerization occurs during which of the following reactions? A) Fructose 1,6-bisphosphate → dihydroxyacetone phosphate and glyceraldehyde 3-phosphate. B) Fructose 6-phosphate → fructose 1,6-bisphosphate. C) Glucose 6- phosphate → fructose 6- phosphate. D) Glucose → glucose 6- phosphate. 3) An intramolecular phosphoryl-group...
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT