Question

Which of the following statements is TRUE about the TCA cycle? a. oxygen is not used and so the TCA cycle can occur in anaerobic conditions b. The TCA cycle produces two water molecules per glucose molecule c. The carbons from a pyruvate are released in one full turn of the TCA cycle d. FAD is a covalently bound coenzyme in the TCA cycle e. More than one of these statements is true In glycolysis, fructose 1, 6-bisphosphate is converted to two products with a standard free-energy change (G") of +23.8 k/mol. Under what conditions (encountered in a normal cell) will the free-energy change (delta G') be negative, enabling the reaction to proceed to the right? a. When there is a high concentration of products relative to the concentration of fructose 1, 6-bisphosphate b. When there is a high concentration of fructose 1, 6-bisphosphate relative to the concentration of products. c. Under standard conditions, enough energy is released to drive the reaction to form products. d. If concentration of the two products are high relative to that of fructose 1, 6-bisphosphate e. The reaction will not form products spontaneously under any conditions because the delta G" is positive.

Answer 1

Q. Which of the following statement is TRUE about the TCA cycle ?

a. oxygen is not used and so the TCA cycle can accue in anaerobic conditions.

b. The TCA cycle produces two water molecules per glucose molecule.

c. The carbons from a pyruvate are released in one full turn of the TCA cycle.

d. FAD is a covalently bound coenzyme in the TCA cycle.

e. More than one of these statements are true.

Ans. d. FAD is a covalently bound coenzyme in the TCA cycle.

Q. In glycolysis, fructose 1,6-bisphosphate is converted to two products with a standard free-energy change

($\Delta G$'’) of 23.8 kJ/mol. Under what conditions (encountered in a normal cell) will the free-energy change ($\Delta G$’) be negative, enabling the reaction to proceed to the right?

a.) When there is a high concentration of products relative to the concentration of fructose 1,6-bisphosphate

b.) When there is a high concentration of fructose 1,6-bisphosphate relative to the concentration of products.

C.) Under standard conditions, enough energy is released to drive the reaction to form products.

d.) If the concentrations of the two products are high relative to that of fructose 1,6- bisphosphate. e.) The reaction will not go to the right spontaneously under any conditions because the $\Delta G$'' is positive.

Ans. b) When there is a high concentration of fructose 1,6-bisphosphate relative to the concentration of products