Contributed by Kate H.
Date of Publication 9/30/11


Figure 1:This is the process in which green plants take different ingredients to make food and oxygen out of thin air.

Photosynthesis is the system where in a plant uses the energy from the sun, chlorophyll, water and carbon dioxide to produce food and oxygen. The sun is pure energy so when it radiates, a miniscule amount of energy goes into Earth’s atmosphere. When plants receive a part of that energy the first link in the photosynthesis chain begins.
There is a two-step process to photosynthesis. Firstly, the sunlight strikes the chlorophyll located in the granum in the leaf of the plant and gives it energy. The granum then splits the energy into hydrogen and oxygen. The oxygen is released in to the air through holes in the leaf. The leftover hydrogen and energy is then moved to the stroma part of the leaf. The energy, hydrogen and carbon dioxide from the air combines to produces food and oxygen.
This is a cycle that plants ALL over the world go through every day.Without photosynthesis we would be swiped of all the green plants, animals, oxygen and much more. The importance of photosynthesis is extensive, so next time you rip a leaf off a plant, you should think about how you might just be killing yourself.

Figure 2:This is the process of photosynthesis

You might wonder if plants use the process of photosynthesis to produce food, then how do algae and bacteria that live on the bottom of the ocean survive without any sunlight to produce their food. The answer is algae and bacteria use a process called chemosynthesis to survive and to produce their own food. Chemosynthesis is the process in which the organisms take energy from the burning crust layer of the Earth. This is able to happen because organisms like bacteria, algae and tube worms are so far below sea level and underground that they are a lot closer to the crust of the Earth. Being closer to the crust then allows them to collect the energy from the burning and produce their own food to survive. Not just the burning, but actual molten lava oozes out energy for the bacteria to receive. They convert the burning lava by turning carbon dioxide into special biochemicals used for producing food. These are Archaebacteria (ancient organisms) and are able to convert the burning is because there is a hypothesis that this process of chemosynthesis was functioning way before the process of photosynthesis existed.


Since animals are not able to make their own food and oxygen they have to eat plants, or animals that eat plants to receive the food and energy. Animals use food and oxygen that is released or stored in the plant for energy. When the animal works off the energy, they give off carbon dioxide. When the plant receives the carbon dioxide that the animal gives off, the carbon dioxide helps the plant go through photosynthesis again. This is like a giant cycle that will go on forever and this cycle is called animal respiration or Oxygen Cycle.

Dictionary.com, 2011

  1. Photosynthesis; The process in green plants and certain otherorganisms by which carbohydrates are synthesized from carbon dioxide and water using light as an energy source.

  1. Chemosynthesis; the __synthesis__ of organic compounds within an organism, with chemical reactions providing the energy source.

  1. Carbon dioxide; a colorless, odorless, incombustible gas, CO 2 , present in the atmosphere and formed during respiration

  1. Bacteria: ubiquitous one-celled organisms, spherical, spiral, or rod-shaped and appearing singly or in chains


Online Databases
  1. Photosynthesis." Britannica Elementary Encyclopedia. Encyclopædia Britannica Online School Edition. Encyclopædia Britannica, Inc., 2011. Web. 12 Sept. 2011.

  1. Photosynthesis." Compton's by Britannica. Encyclopædia Britannica Online School Edition. Encyclopædia Britannica, Inc., 2011. Web. 13 Sept. 2011.

  1. Photosynthesis. Prod. Bean, Norm. Aims Multimedia, 1994. Discovery Education. Web. 20 September 2011.

  1. Alvin Silverstein. “Photosynthesis, Science Concepts”. Brookfield Connecticut: Twenty-First Century Books, 1998. Print.

  1. Alvin Silverstein.”Photosynthesis Science Concepts, Revised Edition”. Minneapolis, MN: Twenty-First Century Books, 2008. Print.

  1. WiseGeek. “What is Chemosynthesis?” wiseGeek. Conjecture Corporation, 2011. Web. 16 September 2011.