Green plants have the ability to make their own food. They do this through a process called photosynthesis, which uses a green pigment called chlorophyll. A pigment is a molecule that has a particular color and can absorb light at different wavelengths, depending on the color. There are many different types of pigments in nature, but chlorophyll is unique in its ability to enable plants to absorb the energy they need to build tissues. 

Chlorophyll is located in a plant’s chloroplasts, which are tiny structures in a plant’s cells. This is where photosynthesis takes place. Phytoplankton, the microscopic floating plants that form the basis of the entire marine food web, contain chlorophyll, which is why high phytoplankton concentrations can make water look green.

Chlorophyll’s job in a plant is to absorb light—usually sunlight. The energy absorbed from light is transferred to two kinds of energy-storing molecules. Through photosynthesis, the plant uses the stored energy to convert carbon dioxide (absorbed from the air) and water into glucose, a type of sugar. Plants use glucose together with nutrients taken from the soil to make new leaves and other plant parts. The process of photosynthesis produces oxygen, which is released by the plant into the air.

Chlorophyll gives plants their green color because it does not absorb the green wavelengths of white light. That particular light wavelength is reflected from the plant, so it appears green.

Plants that use photosynthesis to make their own food are called autotrophs. Animals that eat plants or other animals are called heterotrophs. Because food webs in every type of ecosystem, from terrestrial to marine, begin with photosynthesis, chlorophyll can be considered a foundation for all life on Earth.

 

Chlorophyll

Chlorophyll, like in this cross section of Plagiomnium affine laminazellen is a key component in the process of photosynthesis, which sustains plant life and produces oxygen for the entire planet. Although microscopic in size, chloroplasts like these have a big role to play in the health of the planet.

Noun

plants' green pigment that is essential to photosynthesis.

chloroplast
Noun

part of the cell in plants and other autotrophs that carries out the process of photosynthesis.

marine ecosystem
Noun

community of living and nonliving things in the ocean.

Noun

process by which plants turn water, sunlight, and carbon dioxide into water, oxygen, and simple sugars.

pigment
Noun

material that changes the color of reflected or transmitted light.