Chlorophyll makes it possible for plants to convert carbon dioxide and water, in the presence of sunlight, into oxygen and glucose. During this process of photosynthesis, chlorophyll produces energy, in the form of sugary carbohydrates, which will power all of the plant's essential growth and development. This amazing molecule also gives plants their distinctive green color.

We can understand chlorophyll as fulfilling the same operation as our digestive system. They both take raw materials and convert them into useable sources of energy in the form of glucose. In the case of chlorophyll, all the plant needs is water absorbed through its roots, air absorbed through their pores, and light from the sun's specific spectrum. Then the plant, whether it's a redwood tree, clump of algae, or rose, absorbs glucose into its cells to unfurl another leaf or bud another flower. Energy it doesn't immediately need it stores as starch for later use.

Technically, the chemical reaction of photosynthesis uses an equal number of CO2 (carbon dioxide) and H2O (water) molecules to create the same number of O2 (oxygen) and C6H12O6 (glucose) molecules. This is why we say plants "breathe in" carbon dioxide and "breath out" oxygen. The reaction only occurs if both chlorophyll and sunlight are present. As a photoreceptor, chlorophyll is sensitive to light of a certain spectrum that's emitted by sunlight. This means it can capture the energy of visible light, mostly red and blue. Then it reflects the unneeded green light, giving plants their color.

More specifically, chlorophyll is made of porphyrin ring, which is a circular arrangement of atoms. This enclosed shape lets "free" electrons keep floating around, instead of being captured by a specific atom. Those electrons represent energy ready to get absorbed by a cell that can help the plant grow.

While most of the year, deciduous plants look teal, sage, or chartreuse, during autumn we all watch trees turn striking colors of burgundy, golden, or pumpkin. This happens because the plant loses the pigment chlorophyll as it goes into winter dormancy and other pigments become more visible. Carotenoids, for instance, make fall leaves look yellow and orange.