DENDROLOGY

Detailed explanation-1: -A photon of light energy travels until it reaches a molecule of chlorophyll. The photon causes an electron in the chlorophyll to become “excited.” The energy given to the electron allows it to break free from an atom of the chlorophyll molecule. Chlorophyll is therefore said to “donate” an electron (Figure 5.12).

Detailed explanation-2: -When light strikes chlorophyll (or an accessory pigment) within the chloroplast, it energizes electrons within that molecule. These electrons jump up to higher energy levels; they have absorbed or captured, and now carry, that energy.

Detailed explanation-3: -Light first hits photosystem II, and its energy is absorbed by the pigments within this photosystem. This excites the electrons, and they move to a higher energy level. The electrons then exit the photosystem and move down the electron transport chain.

Detailed explanation-4: -The reaction center chlorophyll then transfers its high-energy electron to an acceptor molecule in an electron transport chain. High-energy electrons are then transferred through a series of membrane carriers, coupled to the synthesis of ATP and NADPH.

Detailed explanation-5: -When chlorophyll absorbs light, it gets excited and emits electrons. These chlorophylls are found in photosynthetic units called Photosystem I and Photosystem II. Each unit has a specific reaction center which contains pigment molecules. These molecules absorb light of different wavelengths and emit electrons.