By Zachary Smallwood and Chelsey Hobman
Photosynthesis is the process plants use to create their own food seemingly from thin air. All plants are able to do this thanks to special cells in leaves, needles, etc called chlorophyll. Plants only need three things for the process to take place, Water, Carbon Dioxide, and sunlight. The majority of plants absorb water through tiny holes in their roots which drink up the water that soaks into the ground. Water is transported from the roots to the veins of the leaf where it is ready to be mixed with the other ingredients. Carbon Dioxide is absorbed from the air thanks to tiny holes on the bottom of leaves called Stomata, because plants do not have lungs to force the breathing process they rely on Diffusion to move the gases through the leaves. Diffusion can be thought of as the temperature change in an open door way, when open the warmer air and colder air equalize, the different gases in the leaf move to fill spaces left by the converted gases. Thankfully the leaf is thin so the gases don't need to travel far. Now to add sunlight, thanks to Chlorophyll plants are able to convert light energy from the sun into chemical energy by absorbing the red and blue waves of light from the sun, and use the converted energy to divide water or H2O into Hydrogen and Oxygen. The fact that plants absorb the blue and red spectrum of light is the reason plants look green to us. The plant then combines the Hydrogen from the water with the Carbon from the air with a little Oxygen added to the mix to create Glucose or sugar, which the plant uses for food. (see formula below)
What happens to the sugar created by the plant?
The Sugar is converted into 4 different products:
- Cellulose for cell walls, important for immune system and over all defense.
Protein for growth and enzymes.
Starch for storage.
Fats and oils for storage.
Where does Photosynthesis take place and why there?
Photosynthesis takes place in the Palisade layer of the leaf which holds the Chloroplasts which contain the Chlorophyll necessary for photosynthesis. (see diagram below) Leaves are well suited to photosynthesis thanks to their broad flat design which has plenty of surface area to catch sunlight, is thin enough for diffusion to take place, and has veins to hold and transport the water. Leaves also have a tough cell walls which help protect the plant from outside threats, their immune system focuses on recognizing patterns rather than individual threats so if the cell wall is breached infected cells warn the healthy cells. Once the alert is up healthy cells near the infection kill themselves off which starves the invader.
If my explanation was hard to follow I have a video.