So chlorophyll is green, and the leaves we see are green. In autumn and winter, the daytime is shorter, plants do less photosynthesis, and leaves contain less chlorophyll, and the amount of synthesis is less than the amount of decomposition. The decomposed chlorophyll is often not supplemented, and it will gradually become other colors, and the color of leaves will change, so this is why leaves turn green in spring and change color in autumn.
Chlorophyll:
First, let's look at chlorophyll. In chlorophyll, there are many different family partners. Many members are common in plants, among which chlorophyll a and chlorophyll b are the most common in higher plants. They are insoluble in water, but soluble in organic solvents such as ethanol and acetone.
Chlorophyll in plants is mainly involved in the light absorption process in photosynthesis. It can absorb most of the red light and purple light, but it reflects green light, so chlorophyll is green, and that's the secret! Like other substances in the living body, chlorophyll is constantly being synthesized and decomposed. Its synthesis process needs strong illumination and high temperature, and at the same time it is very unstable.
Light, acid, alkali and oxidant can decompose chlorophyll. In spring and summer, because the amount of chlorophyll synthesis is greater than that of decomposition, the decomposed chlorophyll can be replenished in time, while in autumn and winter, the amount of chlorophyll synthesis is less than that of decomposition, and the decomposed chlorophyll is often not replenished. So this is why the leaves turn green in spring and turn green in autumn.