Final answer:
In the photosystem, photons excite electrons in chlorophyll pigments, leading to their transfer through the electron transport chain, ultimately aiding in the production of energy carriers like NADPH and ATP.
Step-by-step explanation:
When a photon of light energy is absorbed by a pigment molecule in a photosystem, it excites a delocalized electron, causing it to jump to a higher energy level. This process takes place within the cellular structures called chloroplasts, where photosynthesis occurs. Specifically, chlorophyll, a key photosynthetic pigment, can capture photons and convert that energy. Once the light energy is absorbed, high-energy electrons become excited and are then captured and transported through an electron transport chain (ETC).
The initial energy absorption happens in the antennae complex (or light-harvesting complex) of the photosystem. Energy is transferred from one pigment molecule to another until it eventually reaches the reaction center of the photosystem. In the reaction center, the chlorophyll molecule undergoes oxidation and loses an electron, which can then be used to drive the production of cellular energy carriers like NADPH and ATP.
Therefore, the phytol tail of a pigment molecule does not directly interact with light; instead, it is the specific chlorophyll molecule located in the reaction center of the photosystem that undergoes oxidation and donates an electron, after being excited by the absorbed light energy.