Question

Is NADH a product of light reaction of photosynthesis?

Answer 1

A multitude of photochemical and enzymatic processes are involved in photosynthesis. There are two steps to it. Chlorophyll absorbs light energy during the light-dependent stage (light reaction), which excites some electrons in the pigment molecules to higher energy levels; these leave the chlorophyll and pass along a series of molecules, generating assimilatory power for the dark reaction, where $C{O_2}$ is reduced into carbohydrates.

Complete answer:
NADH is not a result of photosynthetic light reaction. $NA{D^ + }$ performs the function of an electron carrier. When NAD oxidises a molecule by accepting electrons and adding hydrogen ions to the chemical, it produces NADH.
The initial phase of photosynthesis is the light reaction, which converts solar energy into chemical energy. Solar energy is absorbed by chlorophyll during this process, and water is photolyzed.
It emits hydrogen ions as well as oxygen. The hydrogen ion subsequently reacts with $NAD{P^ + }$ to produce NADPH (chemical form of energy).
Chemiosmosis in the thylakoid membrane also yields ATP during the light reaction. NADH, on the other hand, is generated during respiratory cycles.
Additional information:
NAD, or nicotinamide adenine dinucleotide, is found in all living cells and serves as a coenzyme. It comes in two forms: an oxidised form, $NA{D^ + }$ that can absorb a hydrogen atom (a proton), and a reduced form, NADH, that can give a proton.
$NAD{P^ + }$ or nicotinamide adenine dinucleotide phosphate, is a comparable molecule with a similar function, but it differs from $NA{D^ + }$ in that it has an extra phosphate group. $NAD{P^ + }$ is the oxidised form, whereas NADPH is the reduced form.

Note:
The chemical equation of photosynthesis is as follows: $6C{O_2}{\text{ }} + {\text{ }}6{H_2}O{\text{ }}\xrightarrow{{Sunlight,Chlorophyll}}{\text{ }}{C_6}{H_{12}}{O_6}{\text{ }} + {\text{ }}6{O_2}$.
This indicates that light energy collected by chlorophyll (implied by the arrow) converts the reactants, six carbon dioxide molecules and six water molecules, into a sugar molecule and six oxygen molecules, the products.