Which molecule is the main pigment in the green parts of plants?

Which molecule is the main pigment in the green parts of plants? Chlorophyll is the main green pigment in plants.

Chlorophyll molecules are concentrated in chloroplasts, where they capture light energy for photosynthesis. In green plants, chlorophyll a is the principal form, while chlorophyll b acts as an accessory pigment. Together they absorb light especially strongly in blue and red parts of the visible spectrum and reflect more green light, which is why leaves appear green.

The pigment does not simply “make” food by itself. Light energy absorbed by chlorophyll drives reactions that help convert water and carbon dioxide into chemical energy, with oxygen released as a by-product. The reaction centres of photosystems use energized electrons to power the rest of the photosynthetic process.

Chlorophyll is often confused with carotenoids, the yellow and orange pigments that also assist photosynthesis. In autumn, chlorophyll breaks down in many deciduous leaves, revealing these accessory pigments. Chlorophyll also differs chemically from hemoglobin: chlorophyll’s central metal is magnesium, whereas hemoglobin contains iron in its heme group.