Photosynthetic pigments কী?

Chlorophyll $a$ and $b$ are porphyrin rings around a magnesium atom with a long hydrophobic tail anchoring them in the thylakoid membrane; they absorb blue ($430\text{ to }450\,\mathrm{nm}$) and red ($640\text{ to }680\,\mathrm{nm}$) light and reflect green. Carotenoids (isoprenoids, Chapter 9) absorb blue-green light and pass the energy to chlorophyll, and protect it by quenching excess excitation. A few hundred pigment molecules, held on proteins as an antenna (light-harvesting complex), funnel the energy of every absorbed photon to one special pair of chlorophyll $a$ molecules, the reaction centre, where it is turned into chemistry.