Question

Match the organic compounds listed under column I with the explanation given under column I. Choose the appropriate option from the given choices.

Column I	Column II
A. Phosphoenol pyruvate (PEP)	P. 6 carbon compound
B. Ribulose biphosphate (RuBP)	Q. 2 carbon compound
C. Oxaloacetic acid (OAA)	R. 4 carbon compound
D. Acetyl coenzyme-A	S. 5 carbon compound
	T. 3 carbon compound

(a) A - R, B - S, C - T, D - P
(b) A -q, B - R, C - S, D - T
(c) A - T, B - S, C - R, D -q
(d) A - T, B - P, C -q, D - R

Answer 1

Hint: Reaction intermediate is an entity formed from the reactants and reacts further to give the accurate products of a chemical reaction. It may be a highly stable and unstable molecule. All the given compounds in the question are intermediates of various biochemical reactions.

Complete step by step solution:
The chemical formula of Phosphoenolpyruvate (PEP) is ${ C }_{ 3 }{ H }_{ 5 }{ O }_{ 6 }P$. It is a 3 carbon compound.
Ribulose bisphosphate is 5 carbon compounds as its formula is ${ C }_{ 5 }{ H }_{ 12 }{ O }_{ 11 }{ P }_{ 2 }$.
${ C }_{ 4 }{ H }_{ 4 }{ O }_{ 5 }$ is the chemical formula of Oxaloacetic acid (OAA) , therefore it is a 4 carbon compound.
The chemical formula for acetyl coenzyme-A is ${ C }_{ 23 }{ H }_{ 38 }{ { N }_{ 7 }O }_{ 17 }{ P }_{ 3 }S$. Hence it is a 2 carbon compound.

Additional Information:
Let us know more about each chemical compound:
- Phosphoenolpyruvate(PEP): It is an anion, derived from the enol of pyruvate and phosphate. PEP is the highest energy phosphate bond found in organisms. Gluconeogenesis and glycolysis involve PEP. PEP is involved in the biosynthesis of various aromatic compounds and carbon fixation plants. It is also used as the source of energy for the phosphotransferase system in bacteria.
- Ribulose bisphosphate: RuBP is an organic substance. It is involved in photosynthesis. It is a double phosphate ester of ribulose. The most abundant enzyme RuBisCO catalyzes the reaction between RuBP and ${ CO }_{ 2 }$ in photosynthesis.
- Oxaloacetic acid: Oxaloacetic acid or OAA is a crystalline organic compound which is a metabolic intermediate of many processes occurring inside animals, such as in gluconeogenesis, the urea cycle, amino acid synthesis, the glyoxylate cycle, fatty acid synthesis, and the citric acid cycle.
- Acetyl coenzyme-A: It takes part in many biochemical reactions in protein, lipid, and carbohydrate metabolism. It delivers the acetyl group to the citric acid cycle (Krebs cycle) to be oxidized for energy production.
So, the correct answer is option (c) that is ‘A - T, B - S, C - R, D - Q’.

Note: All the above chemical compounds are carbon compounds that act as a reaction intermediate in different biochemical reactions inside the body of an organism. It is necessary to remember the chemical formulas of the given compounds to solve this question. In the case of acetyl coenzyme-A, the acetyl group can be easily transferred to other molecules, and hence, the compound is used as a universal intermediate that provides the ${ C }_{ 2 }$ fragment for various biochemical syntheses.