Plants possess the capability to make their own food, something almost all other organisms living on the planet can’t do.
That is why Plants are known as ‘producers’ in the food web.
Plants also have the ability to make oxygen for us (humans and animals) to be able to breathe and survive.
Plants make oxygen through the process of photosynthesis.
What is Photosynthesis?
Photosynthesis is a process which uses six molecules of water and six molecules of carbon dioxide and converts these reactants into six molecules of carbohydrates (Glucose) and six molecules of oxygen under the presence of sunlight.
Oxygen is basically a byproduct of this process which is then released into the atmosphere to be inhaled by organisms which need oxygen to carry out aerobic respiration.
Aerobic respiration is just a fancy word for ‘using oxygen to make energy’.
Let me show you a chemical equation of how photosynthesis works:
Role of Carbon Dioxide in Photosynthesis
Plants get carbon dioxide directly from the atmosphere.
The atmosphere gets it from many sources like breathing out of various organisms, burning of fossils fuels, volcanic eruptions and other processes that evolve carbon dioxide.
Plants need to absorb carbon dioxide.
They do that through the underside of leaves which contains pore-like openings known as stomata.
The stomata are open throughout the day to allow ample amount of carbon dioxide to be absorbed by the plant so that photosynthesis can be carried out.
At night, this process reverses. The stomata remain closed and the plant produces carbon dioxide since there is no sunlight available to carry out photosynthesis. Hence, during the night, plants respire just like other organisms to produce energy and carry out metabolic processes.
Role of Water in Photosynthesis
Water is absorbed by plants through roots embedded into the soil.
The plant consists of conducting vessels known as Xylem vessels which transport water through the stem up the plant against gravity. Phloem vessels running along xylem vessels carry nutrients from the soil up the tree.
Excess water is either stored by the plant for future use or evaporated from the leaves through stomata. Release of water into the atmosphere in the form of water vapors is known as transpiration.
After plants get Carbon dioxide and water, they are now ready to start producing oxygen and glucose (photosynthesis).
Sunlight – Most important element of Photosynthesis
Sunlight is an important catalyst for this process.
Look at it like this; No sunlight, No Photosynthesis.
We need sunlight to provide energy which will break down carbon dioxide and water molecules. Sunlight is absorbed by organelles known as chloroplast which contain a pigment known as chlorophyll.
Chlorphyll pigment is the reason why plants appear green. It only absorbs a certain wavelength of light (the red and blue parts), reflecting the green, giving the plant its natural green appearance.
That explains Why Plants are Green in Color!
This way the molecules of carbon dioxide and water are broken down in the presence of sunlight to produce glucose and oxygen.
Glucose gives the plant energy, as it does to other organisms, allowing them to carry out various metabolic processes necessary for growth and repair of the plant.
Excess glucose is stored in the form of starch which can be used in future whenever the plant requires it.
It’s also a way of plants to store carbon inside their cells.
Loss of this carbon due to deforestation is the reason why we’re losing the fight to climate change.
Meanwhile, oxygen is released by plants into the atmosphere from stomata. This was the same opening through which carbon dioxide was taken in.
This way, plants are the largest contributors of oxygen on the planet. No organism comes close to the amount of oxygen produced by plants.
Without plants, we definitely won’t have enough oxygen to survive.
Now that we know about how Plants make oxygen for us; How about we go and plant some trees?