Chromophore

A chromophore is the part of a molecule responsible for its colour.

The colour is caused when a molecule absorbs certain wavelengths of visible light. It transmits or reflects only other wavelengths, which causes the colour we see.

In biological molecules that capture or detect light energy, the chromophore is the part of the molecule which responds when hit by light.

Chemical structure of beta-carotene. The eleven conjugated double bonds that form the chromophore of the molecule are highlighted in red

Chromophores make the colour in chromatophores, which are the pigment-containing and light-reflecting cells found in many animals.

Chromophore Media

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  Leaves change color in the fall because their chromophores (chlorophyll molecules) break down and stop absorbing red and blue light.

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  Healthy plants are perceived as green because chlorophyll absorbs mainly the blue and red wavelengths but green light, reflected by plant structures like cell walls, is less absorbed.

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  Phenolphthalein-low-pH-2D-skeletal

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  Phenolphthalein-mid-pH-2D-skeletal