Question

Example of coenzyme is
a. CoA
b. NAD
c. FAD
d. All of the above

Answer 1

Hint: For some biochemical reactions, a substance apart from enzymes and substrate is required. These substances are called coenzymes or cofactors. The coenzymes usually function an acceptor or donor of an atom.

Complete answer:
To answer this question we would like to know about cofactor intimately.

A cofactor could also be a non-protein compound or metallic ion that's required for an enzyme's activity as a catalyst, a substance that increases the speed of a reaction. Cofactors are "helper molecules" for biochemical transformations.

Cofactors have two types: inorganic ions and complex organic molecules called coenzymes. Coenzymes are derived from vitamins and other organic essential nutrients in small amounts. Some scientists limit the use of the term "cofactor" to inorganic substances.

Coenzymes are further divided into two types. the first is known as a "prosthetic group", that has a coenzyme tightly, covalently, and permanently certain to a protein. The second reasonably coenzymes are called "cosubstrates", and are transiently sure to the protein. Cosubstrates could even be released from a protein at some point, then rebind later. Both prosthetic groups and cosubstrates facilitate reaction of enzymes and protein. An inactive enzyme without cofactor is called an apoenzyme, while the full enzyme with cofactor is known as a holoenzyme. Some enzymes or enzyme complexes require several cofactors. as an example, the multienzyme complex pyruvate dehydrogenase at the junction of glycolysis and so the acid cycle requires five organic cofactors and one metal ion: loosely bound cocarboxylase (TPP), covalently bound lipoamide and flavin adenine dinucleotide (FAD), cosubstrates nicotinamide adenine dinucleotide (NAD+) and coenzyme A (CoA), and a metal ion (Mg2+). Organic cofactors are often vitamins or made from vitamins. Many contain the nucleotide nucleotide (AMP) as part of their structures, like ATP, coenzyme A, FAD, and NAD+. This common structure may reflect a customary evolutionary origin as an element of ribozymes in an ancient RNA world. it has been suggested that the AMP part of the molecule are considered to be a kind of "handle" by which the enzyme can "grasp" the coenzyme to switch it between different catalytic centers.

Organic cofactors are further divided into coenzymes and prosthetic groups. Coenzyme refers specifically to enzymes and, as such, to the functional properties of a protein. On the alternative hand, "prosthetic group" emphasizes the character of the binding of a cofactor to a protein (tight or covalent) and, thus, refers to a structural property.

Therefore, the answer is d, all of the above.

 Note:
The International Union of Pure and Applied Chemistry (IUPAC) defines "coenzyme" as a low-molecular-weight, non-protein compound that's loosely attached, participating in enzymatic reactions as a dissociable carrier of chemical groups or electrons; a prosthetic group is defined as a tightly bound, non polypeptide unit during a protein that's regenerated in each enzymatic turnover.