Which of the following is true regarding the reaction shown below?
Pyruvate + HCO₃⁻ + ATP $\to$ oxaloacetate + ADP + P_i
(I) It requires the direct transport of oxaloacetate across the membrane.
(II) It utilizes the malate-aspartate shuttle in some species.
(III) It is essential for gluconeogenesis.
(IV) Its reactants require the function of enzymes which are only found in the cytosol.

Question

Which of the following is true regarding the reaction shown below?
Pyruvate + HCO₃⁻ + ATP

\to

oxaloacetate + ADP + P_i
(I) It requires the direct transport of oxaloacetate across the membrane.
(II) It utilizes the malate-aspartate shuttle in some species.
(III) It is essential for gluconeogenesis.
(IV) Its reactants require the function of enzymes which are only found in the cytosol.

Quizplus · Accepted Answer

The reaction described is the conversion of pyruvate to oxaloacetate, a step in gluconeogenesis, making statement (III) correct. The malate-aspartate shuttle is used in some species to transport intermediates like oxaloacetate across the mitochondrial membrane, validating statement (II). There's no direct transport of oxaloacetate across the membrane as implied in (I), and the enzymes involved are not exclusively found in the cytosol, as the reaction occurs in the mitochondria, making (IV) incorrect.

Which of the Following Is True Regarding the Reaction Shown →\to→

Which of the Following Is True Regarding the Reaction Shown $\to$