Question

Part 1 (2 points)See Hint

(A) Phosphorylation of glucose to produce glucose-6-phosphate has ΔG˚' = ? kJ/mol without the use of ATP.

(B) Coupling phosphorylation with ATP hydrolysis gives ΔG˚' =? kJ/mol.

Part 2 (1 point)

Using concentrations of intermediates found in a cell, the phosphorylation of glucose using inorganic phosphate has ΔG' = 19.7 kJ/mol, while phosphoryl transfer from ATP (ATP investment) results in ΔG' = -34.5 kJ/mol.

What does this tell you about the values of Q and Keq for the phosphorylation of glucose with and without energy investment from ATP?

Choose one:

A. Without ATP investment, Q > Keq, and with ATP investment Q = Keq.

B. Without ATP investment, Q < Keq, and with ATP investment Q > Keq.

C. Without ATP investment, Q > Keq, and with ATP investment Q < Keq.

D. Without ATP investment, Q > Keq, and with ATP investment Q > Keq.

Answer 1

B) is the right answer. Without ATP it becomes impossible to regulate the entry of glucose in glycolysis.one or both substrates need to exceed the solvent capacity of the cell for glucose phosphorylation to occur, without ATP investment. In the 1 st stage of glycolysis, the amount of ATP is too high and tried to inhibit phosphofructokinase leading to inhibition of the entire glycolytic pathway, without ATP investment.