Question

Which one of the following does not involve isomerisation in glycolysis pathway?

• A. Conversion of glucose-6-phosphate to fructose-6-phosphate
• B. Conversion of glycerol aldehyde-3-phosphate to dihydroxyacetone phosphate
• C. Conversion of 3-phosphoglyceric acid to 2-phosphoglyceric acid
• D. Conversion of 2-phosphoglyceric acid to phospho enol pyruvic acid

Answer 1

The correct option is D Conversion of 2-phosphoglyceric acid to phospho enol pyruvic acid

In the ninth step of glycolysis, 2-phosphoglyceric acid (2-PGA) is converted into phosphoenolpyruvic acid (PEP) by removal of one water molecule. These two molecules, 2-PGA and PEP are not isomers. All the other molecules mentioned here are isomers and their reactions are reversible, therefore they are interconvertible.