Full 2L QBank
Biochemistry General 0a0f2c56

Coenzyme A is formed from which vitamin?

A
C
B
B4
C
Nicotinic acid
D
Pentothenic acid
High-Yield Explanation
CoA biosynthesis requires cysteine, pantothenate (vitamin B5), and adenosine triphosphate (ATP).it is naturally synthesized from pantothenate (vitamin B5), which is found in food such as meat, vegetables, cereal grains, legumes, eggs, and milk.Pantothenate (vitamin B5) is phosphorylated to 4'-phosphopantothenate by the enzyme pantothenate kinase (PanK; CoaA; CoaX). This is the committed step in CoA biosynthesis and requires ATP.A cysteine is added to 4'-phosphopantothenate by the enzyme phosphopantothenoylcysteine synthetase (PPCS; CoaB) to form 4'-phospho-N-pantothenoylcysteine (PPC). This step is coupled with ATP hydrolysis.PPC is decarboxylated to 4'-phosphopantetheine by phosphopantothenoylcysteine decarboxylase (PPC-DC; CoaC)4'-phosphopantetheine is adenylylated (or more properly, AMPylated) to form dephospho-CoA by the enzyme phosphopantetheine adenylyl transferase (PPAT; CoaD)Finally, dephospho-CoA is phosphorylated to coenzyme A by the enzyme dephosphocoenzyme A kinase (DPCK; CoaE). This final step requires ATP.

Related Biochemistry MCQs

Practice 2,00,000+ NEET PG Questions Free

Timed mock tests, mistake queue analytics, audio lectures & zero attempt limits on i❤️Exams.

Start Free Mock Test Now