Question

Phosphoglyceraldehyde and dihydroxyacetone phosphate are
A. Isomers
B. Polymers
C. Tautomers
D. Synonyms

Answer 1

Hint: Both phosphoglyceraldehyde and dihydroxyacetone phosphate are the products generated in the fourth step of glycolysis. By looking at the structures of both the compounds and decoding the molecular configuration, the relationship between both the compounds can be assessed easily.

Complete answer:
Isomers:
Isomers are compounds that have the same molecular formula, but different structural formulas and configurations. The molecular formula of both the compounds in C3H7O6P.
Glycolysis is the process by which a molecule of glucose is split into 2 molecules of pyruvic acid. It is a multi-step process that occurs in the cytoplasm of the cell. In this reaction (in 4th step), an enzyme called aldolase splits Fructose -1,6- diphosphate into Phosphoglyceraldehyde and dihydroxyacetone phosphate. Both the compounds are 3 carbon sugars having the same molecular formula.
Now, let us discuss some terminology:
Polymers:
Polymers are materials that are made of a large number of repeating units (molecules). It is basically a macromolecule. Polymers can either be natural or synthetic.
The most common example of a polymer is protein. Proteins are long chains made of several amino acids (subunits).
Tautomers:
Tautomers are the isomers of a compound that exist in equilibrium and are interchangeable by the migration of atoms.
Synonyms:
Synonyms are two or more words that have the same meaning. For example, ‘start’ and ‘commence’ are synonyms.

The correct answer is – A. Isomers.

Note: The compounds phosphoglyceraldehyde and dihydroxyacetone phosphate are interconvertible in the presence of triosephosphate isomerase. However, during the process of glycolysis, phosphoglyceraldehyde enters the next step, but dihydroxyacetone phosphate gets converted into phosphoglyceraldehyde.