Why are plants green?

In school and institute I remember that every time I asked why plants are green , they almost always answered the same thing: because they have a pigment, chlorophyll, which gives them that color. And it is so, according to botanists. But … I have always had the doubt of knowing more, and you?

As well. Fortunately, botanists are (even) more and more experts in the field, and have been able to find out a little more about this topic. This is what they have discovered so far .

The leaves are protected from excess light

Photosynthetic organisms, that is, those that transform the sun’s energy into food and use it to grow, such as plants but also bacteria, are of a specific color. But they have that color for a reason: when they receive the light from the star, it enters the chlorophyll molecules of a single color . In this way, they can automatically protect themselves from changes in sunlight.

In the specific case of plants, they have the green color because for them that is the color range of the solar spectrum that they absorb , the only one that is really adequate, thus avoiding burns.

This explains why a plant that is exposed to the sun for the first time suffers damage: the cells in charge of absorbing the sun’s energy are not prepared for it, thus needing a process of ‘learning’ and adaptation, something they will do whenever genetically needed that light to grow; that is, for example a fern, which lives in the shade, can never get used to living in a sunny area.

Plants adapt to just the right amount of light

But there is still more. According to the researchers, plants have developed their own protector against ultraviolet light . As we know, prolonged exposure to UV rays can cause burns and even skin cancer, plants can also harm them: excessive loss of water that would lead to dehydration, burns, and in more serious cases, death.

To avoid it, curiously, they also do photosynthesis. In order to make it easier to understand, it could be compared to what happens when you water a pot that is filled with a very dry and compact substrate. In these situations, the water that comes out of the drainage holes of the pot is considerably greater than the water that would come out if the same soil were able to absorb it.

If during the photosynthesis, as during the irrigation of very compact soil, the flow of solar energy to the leaves is greater than the cells responsible for absorbing it, they will have to adapt as quickly as possible to adapt and thus reduce the impact which has that overflow of energy from the sun. If it does not, the plant is going to try to somehow expel that energy, thus suffering what is known as oxidative stress, which will damage the cells.

Interesting, don’t you think?

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