This is due to the central position of the Mg++ ion in the chlorophyll molecule.

The pair of chlorophyll molecules at the reaction centre are often referred to as P680.

Light energy that has been absorbed by a leaf will excite electrons in chlorophyll molecules.

The light excites the chlorophyll molecules at the reaction centre and causes an increase in energy.

The reaction center is made of two chlorophyll molecules and is therefore referred to as a dimer.

Nuclear magnetic resonance techniques were employed to study the molecular structures of chlorophyll molecules.

Also, Mg is the coordinating ion in the chlorophyll molecule.

Therefore, this group of compounds causes electrons to accumulate on chlorophyll molecules.

The Mg within the center uniquely defines the structure as a chlorophyll molecule.

The images reveal that the chlorophyll molecules inside chlorosomes have a nanotube shape.