Why leaf appears green

Along with the green pigment are yellow to orange pigments, carotenes and xanthophyll pigments which, for example, give the orange color to a carrot. Most of the year these colors are masked by great amounts of green coloring. But in the fall, because of changes in the length of daylight and changes in temperature, the leaves stop their food-making process.

The chlorophyll breaks down, the green color disappears, and the yellow to orange colors become visible and give the leaves part of their fall splendor. At the same time other chemical changes may occur, which form additional colors through the development of red anthocyanin pigments.

Some mixtures give rise to the reddish and purplish fall colors of trees such as dogwoods and sumacs, while others give the sugar maple its brilliant orange. The autumn foliage of some trees show only yellow colors. Others, like many oaks, display mostly browns. All these colors are due to the mixing of varying amounts of the chlorophyll residue and other pigments in the leaf during the fall season.

Green light is not absorbed but reflected, making the plant appear green. Chlorophyll is found in the chloroplasts of plants. There are various types of chlorophyll structures, but plants contain chlorophyll a and b. These two types of chlorophyll differ only slightly, in the composition of a single side chain.

Absorption spectra showing how the different side chains in chlorophyll a and chlorophyll b result in slightly different absorptions of visible light. Light with a wavelength of nm is not significantly absorbed by chlorophyll a, but will instead be captured by chlorophyll b, which absorbs strongly at that wavelength. The two kinds of chlorophyll in plants complement each other in absorbing sunlight. Plants are able to satisfy their energy requirements by absorbing light from the blue and red parts of the spectrum.

However, there is still a large spectral region between and nm where chlorophyll absorbs very little light, and plants appear green because this light is reflected. Chlorophyll is a compound that is known as a chelate. A chelate consists of a central metal ion bonded to a large organic molecule, composed of carbon, hydrogen, and other elements such as oxygen and nitrogen.

Chlorophyll has magnesium as its central metal ion, and the large organic molecule to which it bonds is known as a porphyrin. The porphyrin contains four nitrogen atoms bonded to the magnesium ion in a square planar arrangement. Chlorophyll occurs in a variety of forms. Chlorophyll does not contain chlorine as the name might suggest; the chloro- portion stems from the Greek chloros, which means yellowish green. The element chlorine derives its name from the same source, being a yellowish-green gas.

Vegetation will not appear to animals as it does to us. Although our color perception is the most advanced amongst mammals, humans have less effective color vision than many birds, reptiles, insects and even fish. Tyson Brown, National Geographic Society. National Geographic Society. For information on user permissions, please read our Terms of Service. If you have questions about how to cite anything on our website in your project or classroom presentation, please contact your teacher.

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You cannot download interactives. Marine ecosystems contain a diverse array of living organisms and abiotic processes. From massive marine mammals like whales to the tiny krill that form the bottom of the food chain, all life in the ocean is interconnected. This is an article from Curious Kids , a series for children. All questions are welcome — serious, weird or wacky! Without photosynthesis there would be no plants or people on Earth. Dinosaurs would not have been able to breathe and the air and oceans would be very different from those we have today.

So the green chemical chlorophyll is really important. All leaves contain chlorophyll, but sometimes not all of the leaf has chlorophyll in it.