Question

Draw the enediolate intermediate of the ribulose-5-phosphate epimerase reaction (Ru5P → Xu5P).

Short answer

The figure is as follows.

Step-by-step solution

Pentose phosphate pathway

The pentose phosphate pathway contains two stages, oxidative and non-oxidative, which is another option for glucose oxidation.

Enediolate intermediate in Pentose Phosphate Pathway

Isomerization and epimerization processes proceed in step 2 of the pentose phosphate cycle. In the presence of the enzyme ribulose-5-phosphate epimerase, ribulose-5-phosphate is transformed to xylulose 5-phosphate in this step.In a reversible route, this whole conversion process proceeds through a 1, 2-enediolate intermediate to convert xylulose 5-phosphate. In addition to pentose sugar and glucuronate interconversion, the enzyme ribulose-5-phosphate epimerase is also involved.

Conversion of Ribulose-5-phosphate to Xylulose-5-phosphate

Hence, the enediolate intermediate in the ribulose-5-phosphate epimerase process transforms ribulose-5-phosphate to xylulose-5-phosphate.