Photosynthesis

Pier Press is located in southern Virginia, and the spring leaves have not yet unfurled. When they do, their green chlorophyll will begin a remarkable process known as photosynthesis, the process by which plants use sunlight to create chemical energy. The word itself explains what it means: photo means "light" and synthesis means "to put together; to make." Photosynthesis is ultimately responsible for the oxygen in the air we breathe. And, whether we eat plants or eat animals that eat plants, it is the fundamental process that starts the food chain.

To perform photosynthesis, plants employ multiple complex chemical processes that take place in a precise chain of events. An overly simplified explanation goes like this: Molecules of carbon dioxide (each carbon dioxide molecule includes one carbon atom and two oxygen atoms) and molecules of water (each water molecule includes two atoms of hydrogen and one atom of oxygen) are disassembled. Plants use the energy present in some wavelengths of sunlight to perform this task. Then, enzymes in the plants re-combine the raw materials to produce the sugar (glucose) the plants need. Oxygen is a by-product of this process.

Studying photosynthesis. This image depicts the process of taking gas exchange measurements at the Coweeta Hydrologic Lab, U.S. Forest Service, North Carolina. (Photo credit: Paul Bolstad, University of Minnesota, Bugwood.org; this work is licensed under a Creative Commons Attribution 3.0 License.)

Studying photosynthesis. This image depicts the process of taking gas exchange measurements at the Coweeta Hydrologic Lab, U.S. Forest Service, North Carolina. (Photo credit: Paul Bolstad, University of Minnesota, Bugwood.org; this work is licensed under a Creative Commons Attribution 3.0 License.)

Diatoms are a kind of algae. They are responsible for a significant portion (some estimates range from 20% to 40%) of the Earth’s oxygen. This photomicrograph shows the structures of fifty diatom species arranged in a circle. Diatoms form the base of many marine and aquatic food chains. The cell wall of a diatom is called a frustule. When diatoms die their frustules form sediments known as diatomaceous earth. (Photo credit: Randolph Femmer, courtesy U.S. Geological Survey, 2005).

Here are some links where you can learn more about photosynthesis:

  • Photosynthesis, a Bozeman Science video (12:26) by Paul Anderson, starts with a basic overview and then delves more deeply into the chemical processes. Diagrams help depict the complex pathways involved.
  • Photosynthesis, an article posted by Clermont College, University of Cincinnati, describes leaf structures involved in photosynthesis, the chemical reactions that require light (light reactions), and the Calvin cycle by which sugar molecules are assembled.

And, here are some links to learn more about recent research related to photosynthesis:

This is a panoramic view (360 degrees) from the top of a 148-foot observation tower at a study site in the Amazon forest near Santarém, Brazil. An instrument on the tower monitors atmospheric conditions and the solar radiation available for photosynthesis. Data are being used to help researchers better understand how photosynthesis in tropical forests responds to seasonal variations in climate. (Photo credit: Dennis Dye, courtesy U.S. Geological Survey, 2012)

This is a panoramic view (360 degrees) from the top of a 148-foot observation tower at a study site in the Amazon forest near Santarém, Brazil. An instrument on the tower monitors atmospheric conditions and the solar radiation available for photosynthesis. Data are being used to help researchers better understand how photosynthesis in tropical forests responds to seasonal variations in climate. (Photo credit: Dennis Dye, courtesy U.S. Geological Survey, 2012)

This article originally appeared in Observations: A Pier Press® Newsletter, March 2015. If you're not already a subscriber, consider subscribing today. It's free!