Amongst the basic needs that every plant needs to stay alive and grow, food ranks up there. So, how do plant get their food?
They do so through the process of photosynthesis, a process that is not only vital to plants, algae, and some organisms but is also critical for the existence of the majority of life here on earth.
All green plants and trees use sunlight, water, and carbon dioxide to create their main source of energy, which is food.
Although the photosynthesis process is performed differently in different species, the process starts the same way in all. It starts when plant proteins that contain the green chlorophyll pigment absorb energy from sunlight.
The plant then converts it into electrical energy and then converts this into chemical energy. It then inputs water and carbon dioxide into the chemical energy, to give forth carbohydrates that it uses for its nourishment.
Photosynthesis can be defined as the process through which energy is transferred from the sun to a plant.
The process is not only important for being largely responsible for the production and maintenance of oxygen content of the atmosphere of planet earth, but it also supplies a major part of the energy that is essential for sustaining life on earth.
The sugars built by plants during photosynthesis are consumed by humans to drive daily activities.
Does Photosynthesis Have any Waste Products?
Yes, photosynthesis does have a waste product: oxygen.
For every single molecule of glucose that is produced in the process of photosynthesis, it requires six molecules of water, and six molecules of carbon dioxide.
While the water gets split during the light reaction, it releases six molecules of oxygen as a waste product, that is liberated out and into the environment through the opened stomata of the leaf. The oxygen is then utilized by animals and humans during the respiration process.
In the photosynthesis process, the initial process involves decomposing water into oxygen and hydrogen by the use of direct sunlight.
While oxygen gets released as waste, the hydrogen and carbon dioxide then get converted into complex compounds and finally into starch, which is a stable organic compound and water.
Starch, therefore, becomes the first product to be converted in all plants, which they use grow, and produce fruits and flowers too.
Through the photosynthesis process, plants get to help humans who are heterotrophs. This is because humans get their energy by consuming glucose stored in plants.
They do so by consuming the plants directly or by consuming animals that feed on these plants.
10 Facts About the Photosynthesis Process
- Chloroplasts give the leaves the green color, and the molecules in chlorophyll absorb light wavelengths from the sun, mainly red and blue, and convert them into chemical energy.
- Chloroplast has two main parts-grana and stroma. Grana has disc-like compartments where light-dependent reactions occur, while grana are the fluid surrounding the stroma, where light-independent reactions take place.
- The first stage of photosynthesis is the light-dependent one, where energy is captured from the sun that breaks down water molecules to oxygen and hydrogen atoms. This takes place in the leaf’s mesophyll, which is the middle layer of the leaf, and inside the chloroplast. The electrons are then passed along a series of proteins to make molecules ATP or NADPH that are electron carriers.
- The light-independent Calvin cycle, which is the second stage of photosynthesis uses energy created in the light-dependent reactions to make carbohydrates. The energy is used to keep the process going till sugar molecules that contain six carbons are created.
- Photosynthesis evolved as a way that plants store energy in solar radiation in the form of high energy electrons that are carbohydrate molecules. One molecule of glucose is made from six water molecules and six carbon dioxide molecules. During the reaction, oxygen molecules are yielded as a waste product.
- Water used for photosynthesis is transported through the xylem tissue to the leaves, while carbon dioxide enters through stomata, and oxygen exits through the stomata too. The stomata are small openings on the underside of the leaf, that allow for the exchange of carbon dioxide and oxygen gases, and also plays the role of regulating water loss by swelling or shrinking per the osmotic changes.
- Glucose molecules that are formed during the photosynthesis process are simple sugars. These are building blocks for complex molecules-cellulose and starch. Plants use cellulose in the plant’s structure for the plant’s cell walls, while starch is used as stored energy.
- Simple sugars manufactured during photosynthesis become a source of energy to the plant and are used to help them grow. They are sent to different parts of the plant like stems, leaves, roots, flowers, fruits, and seeds.
- Winter and autumn make the leaves slowdown in the making of chlorophyll and change color from green to other pigments.
- Other single-celled organisms contain chlorophyll. Protists like algae and some bacteria like cyanobacteria, which are mostly found in aquatic environments also use photosynthesis.
- The mirror reaction of photosynthesis is cellular respiration. This entails using the chemical energy that is stored in the sugars for growth and reproduction. Glucose combines with oxygen to give forth carbon dioxide and water.
Benefits of Waste Product of Photosynthesis
While plants generate oxygen during the photosynthesis process, they constantly need oxygen to survive.
Just like animals, during the respiration process, plants use oxygen to break down sugars and release energy, which they need for their uses like growth.
This mostly happens at the time when the plant is not able to access light, and so take in more oxygen than they produce at this time. However, growing plants release more energy than that which they consume.
Oxygen released by plants during photosynthesis is essential to animals and humans for breathing and energy. The human body only gets 30%of its energy from food, 70% is from oxygen.
Food is a form of sun energy, which the body uses directly. Humans and animals breathe in air that is rich in oxygen to fill the tiny air sacs in their lungs, allowing body cells to pick up the oxygen and distribute it across the entire body cells.
This oxygen is then used in the process of breaking down body sugars to create energy. People have also come up with ways of pressurizing air as a way of combating elevation related to sickness as a result of moving into some high-elevation areas. The human body is, after all, 60% oxygen.
Pressurized oxygen is sold in high pollution areas like China and Russia, which people buy as a method of improving health, mood, or productivity.
Supplemental oxygen is vital in hospitals and homes, as it is important for use on people that have breathing disorders or other respiratory system challenges.
It is also used when conducting surgeries to keep the vitals functioning, for those patients that have been intentionally rendered paralyzed to allow for the medical procedure to be carried out.
There are certain anaerobic bacteria that on exposure to sufficient oxygen, they die. Oxygen is therefore used in such instances as a sterilizing agent.
Oxygen is used in applications that require high temperatures like welding torches in metal works, steelworks where it helps convert carbon to carbon dioxide and help reduce iron oxides.
Things like vehicles and generators that are not linked to their own electrical supply require oxygen to produce energy.
Oxygen is forced through the water to metabolize waste products in water by increasing the production of bacteria. It is therefore used in water purification and sewage treatment plants.
Oxygen is used in combustion to degrade hydrocarbon compounds and liberate carbon dioxide and water, a process that can also produce propylene, ethylene, and acetylene hydrocarbons.
Rockets and missiles use oxygen as an oxidizing agent. Here, oxygen reacts with liquid hydrogen, producing that thrust that is needed for take-off. Also, the astronaut spacesuits are made in a form that is nearly pure oxygen.
It is good to note that increasing pollution, as is seen around the world, may cause serious havoc in the world if it gets to a point where future photosynthesis cannot support it, and end up causing global warming.
With the process being the most important biological process under planet earth, as we depend on it for existence in many ways than most consider, there is a need to encourage the conversations around global climate change and its effects on photosynthesis.
