First, there is the NAD (Nicotinamide Adenine Diphosphate). This is a coenzyme used in the cellular respiration in eukaryotes. The main function of NAD is to carry hydrogen and electrons from one reaction to another in the oxidation-reduction reactions.
As it is, NAD contains an oxidized form and a reduced form. The oxidized form of the NAD+ to NADH and the reduced form is NADH.
NAD and NADH
Between NAD and NADH, the difference is that NAD is the coenzyme whereas NADH is the reduced form of the NAD. NADH is produced in the glycolysis and Krebs cycle and is used in the production of ATP in the electron transport chain.
NAD is an abundant coenzyme that acts as the oxidizing-reducing agent inside the cell. NAD+ is the oxidized form of NAD. It is the naturally-occurring form of NAD inside the cell and is involved in the reactions of the cellular respiration (glycolysis and Krebs cycle).
It acquires a hydrogen ion and two electrons and is reduced to NADH. NADH is used to generate ATP in the electron transport chain. Hydroxylases and reductases also use NAD+ as an electron carrier.
Difference Between NAD and NADH
The proteins embedded in the inner membrane of mitochondria gets electrons from NADH molecules. These electrons are transported through different protein molecules of the electron transport chain.
They are ultimately obtained by oxygen molecules to form water. This means oxygen molecules are the final electron acceptors in the aerobic respiration.
The energy released in the process is used to produce ATP by oxidative phosphorylation. In fermentation, other molecules serve as final electron acceptors since oxygen is absent in the medium. The regeneration of NAD+ occurs through substrate-level phosphorylation.
NADH is the reduced form of NAD+, which is produced in the glycolysis and Krebs cycle.
NAD is a coenzyme compound while NADH is the reduced form of the NAD.
Similarities Between NAD and NADH
NAD+ is synthesized in two different pathways inside the cell – the Tryptophan pathway and vitamin B3 pathway.
The starting product of the tryptophan pathway is the amino acid, tryptophan. The starting product of the vitamin B3 pathway is vitamin B3 (commonly known as niacin or nicotinic acid).
Again, NADH is the reduced form of NAD+. In turn, NAD is produced in the glycolysis and Krebs cycle. In glycolysis, two NADH molecules are produced per glucose molecule. Six NADH molecules are produced in the Krebs cycle per glucose molecule.
These NADH molecules are used in the electron transport chain to produce ATP molecules.
Both NAD and NADH carry hydrogen and electrons from one reaction to another.Both NAD and NADH contain two ribose molecules attached to the phosphate groups, a nicotinamide, and an adenine base.Both NAD and NADH are nucleotides, and both NAD and NADH are involved in catabolic reactions.
Most of the dehydrogenases use NAD and NADH.
Synthesis
NAD is synthesized either by tryptophan pathway or vitamin B3 pathway. NADH is the synthesized in glycolysis and Krebs cycle.
In its existing form, NAD+ is the naturally-occurring form of NAD inside the cell. In turn, NADH is the reduced form of the NAD.
In NAD, NAD+ serves as an electron and hydrogen acceptor. On the other hand, NADH serves as an electron and hydrogen donor.
Types
NAD and NADH are two types of nucleotides involved in the oxidizing-reducing reactions of cellular respiration. The naturally-occurring form of NAD inside the cell is NAD+. It serves as a hydrogen and electron acceptor in both glycolysis and Krebs cycle.
NADH is the reduced form of NAD. It is used in the electron transport chain to produce ATP by oxidative phosphorylation. The main difference between NAD and NADH is the role of both compounds in the cell.
Glycolysis
NAD+ is a coenzyme for a variety of dehydrogenases that mediate redox reactions. Typically, it accepts a high-energy electron from glyceraldehyde 3-phosphate to become NADH during glycolysis.
This is the process that converts NAD+ to NADH. After the process of converting NAD+ to NADH. It gains two things. First, a charged hydrogen molecule (H+) and next, two electrons.
As electrons are negatively charged, the combination of the positively charged NAD+ and H+, coupled with two electrons, effectively cancel each other out and neutralize the resulting NADH molecule.
When NAD+ takes an electron from glucose, it becomes NADH, the reduced form of the molecule.
The NADH then transports this electron to the mitochondria where the cell can take the energy that is stored in the electron. NADH then donates the electron to oxygen, converting it back to NAD+.
Metabolism
In metabolism, both NAD+ and NADH play important roles as coenzymes in redox reactions, and an imbalance in their ratio can impair flux through these pathways’ reactions, resulting in dysregulated cellular metabolism.
However, ATP generated via glycolytic reactions is critical for NAD + regeneration from NADH.
NADH
NADH stands for “nicotinamide adenine dinucleotide (NAD) + hydrogen (H).” It occurs naturally in the body and plays a role in generating energy.
The NADH produced by the body is involved in making energy in the body. Taking NADH supplements might affect blood pressure and have other effects.
Other uses
People use NADH for chronic fatigue syndrome (CFS), high blood pressure, high cholesterol, athletic performance, depression, Parkinson disease, and many other conditions.
However, there is no good scientific evidence to support these uses. Moreover, people should not confuse with niacin, niacinamide, or nicotinamide riboside. These are not the same.
Uncertain medical values
There is interest in using NADH for a number of other purposes, but there isn’t enough reliable information to say whether it might be helpful.
People are taking NADH by mouth (orally), either alone or together with coenzyme Q10, in the hope that it might alleviate somewhat the symptoms of CFS(chronic fatigue syndrome).
NADH has been used by adults in doses of 5-10 mg takenorally for up to 24 months. It is best to consult with a healthcare provider to find out the best for a specific condition.
When taken orally, NADH is possibly safe for most people when used for up to 12 weeks. It’s usually well-tolerated.
At present, there is not enough reliable information to know if NADH is safe to use for women when pregnant or are breast-feeding. Avoid using until further notice
