Tag Archives: Pigment

A Symbol of Hope

During intense winters, plants and trees go into a dormancy a period of stagnation. They withdraw the chlorophyll -a pigment responsible for green colour and a must for photosynthesis– from the leaves because they know that Sun is not going to come up strongly for photosynthesis to happen and food making process to start. The leaves change color to yellow, orange and mixture of these colors. Because besides chlorophyll which overpowers the colors of other pigments there are Xanthophylls which are yellow pigments, and carotenoids (the pigment which imparts the beautiful color to carrots, papaya, and mangoes and so on) which give leaves an orange color.

Slowly the leaves die and begin falling down. The tree branches become nude. But tree is not dead. It is waiting patiently for the tough time of winter to be over. As soon as the winter starts receding, the new leaves begin coming forth. The new beginning of life. At first, due to the absence of chlorophyll, the color of other pigments shine. Leaves are beautiful translucent. As the sun starts coming regularly with renewed force, chlorophyll starts building up masking the color of other pigments. Soon the leaves become intense green shade.

Thus the the new leaves are a symbol of Spring and new hope of brighter future. Let us hope and pray to God this also happens to the world….

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Color Changes in Chameleons

We have been told that chameleons change their color to conceal themselves by blending in with their surroundings. In fact, a person who is changeable or inconstant in behavior is called chameleon. It has been proved that the facts are something else. And it is a myth. .  Most of the reason chameleons change colour is as a signal, a visual signal of mood and aggression, territory and mating behaviour.

The chameleons are master molecular scientists. Their skin has transparent layers in which different color compounds are tucked away. These specialized cells store the different color compounds and these cells are called chromatophores. They contain various pigments.  These are xanthophores, containing particular specialised pigments that have a yellow colour.  Beneath that are pigment cells which are called erythrophores which have a red colour in them.  Beneath that, another layer of cells called iridiphores have a blue coloured pigment called guanine, which is actually also used in making DNA.  And underneath that is another layer of cells called melanophores which have a brown pigment – melanin – in them.

As such these pigments are confined to sacs. Depending on the signals from the brain, pigments are leaked and depending on the amounts released, mixed colors are formed. This is like artist mixing the different amounts of colors in the color palette. So if you mix red and yellow, you get orange for example, and this is how chameleons do this.  They mix different contributions of these chromatophores.

So a calm chameleon is a pale greeny colour.  When it gets angry, it might go bright yellow, and when it wants to mate, it basically turns on every possible colour it can which shows that it’s in the mood.  This is not unique to chameleons.  Other animals also have these chromatophores. Cuttlefish are another very elegant example of how this works.  So it’s not so much to do with camouflage.  It’s more to do with communication.