Question

What is common between NAD and FAD
A)Both are coenzymes
B)Both are derived from proteins
C)Both acts as oxygen carriers
D)All of the above

Answer 1

Hint: There are two factors involved in cellular respiration. They are Nicotinamide adenine dinucleotide (${NAD}^{+}$) and flavin adenine dinucleotide (${FAD}^{+}$). They both are in charge of accepting the high-energy electrons and carry them to the electron transport chain. There they used to synthesize ATP molecules.

Complete answer:

NAD	FAD
-Nicotinamide Adenine Dinucleotide in its oxidized state called ${NAD}^{+}$ and after accepting the electrons, it is called NADH.	-Flavin Adenine Dinucleotide in its oxidized state called ${FAD}^{+}$ and after accepting the electrons, it is called FADH.
-This compound is derived from vitamin Niacin, also known as B3.	-This compound is derived from vitamin Riboflavin, also known as B2.
-Nicotinamide Adenine Dinucleotide (NAD) is coenzymes that take part in oxidation and reduction reactions.	-Nicotinamide Adenine Dinucleotide (NAD) is also coenzymes that take part in oxidation and reduction reactions.
-It accepts electrons during the catabolic process. Hence it is an electron carrier and takes part in the breakdown of organic molecules like carbohydrate and lipids.	-It also accepts electrons during the catabolic process. Hence it is also an electron carrier and takes part in the breakdown of organic molecules like carbohydrate and lipids.
-After accepting the electron, these reduced coenzymes donate electrons to other biochemical reactions mostly involved in an anabolic process.	-After accepting the electron, these reduced coenzymes donate electrons to other biochemical reactions mostly involved in an anabolic process.

Additional Information: -${NAD}^{+}$ is often found in co-occurrence with a dehydrogenase enzyme. This enzyme removes two hydrogen atoms when as a hydride ($H^{-}$)and another as a hydrogen cation($H^{+}$).
-${NAD}^{+}$ binds with the hydride and produces a reduced compound of nicotinamide Adenine Dinucleotide (NADH) and II hydrogen atom release into the solution.
-${FAD}^{+}$ also works in the co-occurrence with the dehydrogenase enzyme. The enzyme removes two hydrogen atoms (each proto with one electron).${FAD}^{+}$ is bonded with both the hydrogen atoms. This reaction does not release hydrogen cation into a solution like NAD.
So, the correct answer is,” Both are coenzymes”.

Note: -As a comparison to NADH, for the delivery of hydrogen and electrons to the biochemical process, FADH is also very important and uses electrons and hydrogen to make ATP.
-The main difference is the acceptance of hydrogen atoms that can be seen between FAD, flavin adenine dinucleotide, and NAD, nicotinamide adenine dinucleotide.
-FAD can accommodate two hydrogens whereas NAD accepts just one hydrogen.