Why are leaves green?

The leaves are often green, but the reason why the leaves are green is not sure many people know. Let's find out why the leaves are green.

The green color on the leaf is caused by chlorophyll inside the chloroplast. There are actually other substances in the leaves that are yellow, orange and red, but due to the minor proportion, the green color of the chlorophyll remains outstanding.

So why is chlorophyll green?Chlorophyll is green to absorb the best sunlight , which is infrared and red. Remember a little bit about spectral physics, the light that we see emitted from leaves is reflected light that is not absorbed by leaves. This means that other colors are absorbed (especially red and blue) and green is ignored.

Leaf.

However, for some reason, the leaves of some plants are not green.

Some seaweed species have red or brown leaves so that it absorbs blue light well because red light is difficult to penetrate seawater. So in shallow water we see that seaweed is green, but to deep water, it gradually turns to brown and red.

Another common exception is Begonia . The leaves of this plant have two colors, the upper face is green and the lower is reddish brown. This is because this plant usually lives in the dark areas under the canopy of other plants. The upper surface can catch some light left over from above. The underside is reddish-brown in order to well absorb the weak rays reflected from the ground or from its other leaves.

Begonia.

Chloroplasts are like a miniature machine that absorbs solar energy to produce energy for plants. This machine works for a while also becomes old and replaced. There are 2 schools. Evergreen trees replace chloroplasts on leaves every time they expire. Seasonal deciduous trees do not replace the chloroplasts alone but replace all the leaves at the end of autumn.

In early autumn, the leaves begin to gradually turn yellow or red because chlorophyll is collected by the plants . The yellow or red colors also gradually disappear due to the fact that other substances on the leaves are also gradually recovered by the plants. At the end of autumn, the leaves are only brown and fall off. Dry leaves are brown in color, perhaps a mixture of what remains on the leaves.

Maple leaves.

Maple leaves.