Question

In EMP pathway,ATP is directly formed in the conversion of
I)Fructose 1 , 6 -bisphosphate to glyceraldehyde -3-phosphate
II)Phosphoenolpyruvate to pyruvate acid
III)1 , 3 -bisphosphoglyceric acid to 3-phosphoglyceric acid
IV)3-phosphoglyceric acid to 2-phosphoglyceric acid
The correct combination is

• A. IV ,I
• B. II , IV
• C. III ,II
• D. I ,III

Answer 1

The correct option is C III ,II

Glycolysis is the metabolic process that involves the breakdown of one molecule glucose into two molecules of pyruvic acid to extract energy for cellular metabolism. The scheme of glycolysis was given by Gustav Embden, Otto Meyerhof, and J. Parnas, and is often referred to as the EMP pathway.

The steps of EMP pathway are as follows:

1) Glucose and fructose are phosphorylated to give rise to glucose-6- phosphate by the activity of the enzyme hexokinase and by utilizing ATP.

2) The phosphorylated form of glucose then isomerises to produce fructose-6-phosphate.

3) The conversion of fructose 6-phosphate to fructose 1, 6-diphosphate occurs by the utilization of ATP molecule.

4) Fructose 1, 6-diphosphate is split into dihydroxyacetone phosphate and glyceraldehyde-3-phosphate.

5) When glyceraldehyde-3-phosphate gets converted into 1, 3-bisphosphoglyceric acid, NAD+ reduces to NADH and H+.

6) The conversion of 1, 3-bisphosphoglyceric acid to 3-phosphoglyceric acid, is an energy-yielding process, i.e. ATP is released in this step.

7) 3-phosphoglyceric acid is converted into its isomer, 2-phosphoglyceric acid.

8) 2-phosphoglyceric acid loses a molecule of water, becoming phosphoenolpyruvate.

9) Phosphoenolpyruvate loses its phosphate group to get converted into pyruvic acid with the release of ATP molecule.

So, the correct option is C.