Most of us know that humans and animals inhale oxygen and exhale carbon dioxide, which is absorbed by plants, but do we know why do plants need carbon dioxide?
What is the food source for plants?
There do they get the energy to grow?
There is a lot of talk on why carbon emissions are dangerous for the climate, but do we why it is dangerous for the environment?
Carbon dioxide is an important element in photosynthesis, which is a process that converts energy from sunlight to chemical energy stored in glucose.
The by-product of photosynthesis is oxygen, which is an essential element of life.
Carbon dioxide is important for photosynthesis because it provides the carbon required for the plant to produce glucose, which is used to complete cellular processes in the plant.
These cellular processes enable the plants to develop seeds, grow, make fruit, and form flowers.
What is photosynthesis?
During photosynthesis, plants gather carbon dioxide and water from air and soil. The water goes through oxidation, while the carbon dioxide goes through reduction.
This process converts carbon dioxide into glucose and the water into oxygen. Inside in the plant cell, there is a light-absorbing pigment called chlorophyll, which has the role of absorbing blue and red light waves from sunlight and reflect green light waves.
This gives the plants their green color. Chlorophyll allows us to absorb the energy needed to complete the photosynthesis process.
The process of photosynthesis can be divided into two main types of reactions. There are light-dependent reactions and light-independent reactions.
The light-dependent reactions convert chemical energy in the form of NADPH and ATP. The light-dependent reactions include the Calvin Cycle, during which energy is used to gather glucose from carbon dioxide.
Carbon molecules are converted from carbon dioxide to stored fuel in the form of carbohydrates. These carbohydrates are used as a source of food or energy for the plant.
The process of photosynthesis is often written as the following chemical formula:
6CO2 + 6H2O → C6H12O6 + 6O2
This means that six molecules of carbon dioxide (CO2) react with six molecules of water (H2O) to form glucose molecules and oxygen.
It is not just plants that can photosynthesize, but other eukaryotic and prokaryotic organisms also able to harvest their energy from photosynthesis.
The importance of carbon dioxide for plants
Photosynthesis is critical for the existence of life on earth. In a way, how the energy in the biosphere reaches living things on earth. The organisms that use photosynthesis form the primary producers of oxygen in the world.
Almost all of the oxygen on earth comes from photosynthesis. If this process was to stop, the world is left with no oxygen. The importance of photosynthesis extends to many life forms on earth, including plants.
Only organisms that could exist without oxygen are certain bacteria. Everything else is dependent on photosynthesis to produce oxygen.
It has been established that the process of photosynthesis cannot be completed without carbon dioxide. People often used they are feeding the plant by watering them or providing fertilizers, but the needs of the plant are not complete without carbon dioxide and sun.
Photosynthesis is one of the most important processes on earth. Not only is it used by plants but also other microorganisms and algae. Just as humans and animals need respiration to stay alive, plants need photosynthesis.
The entire process of photosynthesis can be summarized as a way to transfer energy from the sun to the plant.
Different types of plants have evolved to require a different amount of water, sunlight, and carbon dioxide. Plants in the desert, such as a cactus plant, are naturally designed to require less water, whereas plants in a pond as an abundance of water. Similarly, different plants require different levels of carbon dioxide.
What effect does increasing levels of carbon dioxide have on photosynthesis?
The amount of carbon dioxide in the world is increasing. According to Climate.gov, carbon dioxide levels in the world are its highest level since 800,000 years.
There are several reasons for the rise in carbon dioxide levels. The primary reason is the increase in the burning of fossil fuels such as oil and coal. These fossil fuels contain carbon, which has been absorbed through hundreds of years of photosynthesis.
You might think that if carbon dioxide is so important to plants, an increasing level of carbon dioxide should be immensely useful to plants, including food crops.
The level of food production in the world should increase, and the entire talk of fossil fuels being bad for the environment should be rubbished. It is true that in complete isolation, increasing levels of carbon dioxide will increase photosynthesis.
However, it is important to note that plants require more than just carbon dioxide to function. They need water, nitrogen, and other nutrients to function.
Any limitations of these essential elements will not allow the plants to grow. This is why plants need fertilizers that contain nitrogen. Any positive effect of increasing carbon dioxide in the world is negated by the increase in global temperature caused by global warming.
The increase in temperature has a devastating effect on plant life.
Future of photosynthesis
The increasing world population and the use of fossil fuels are putting an intense strain on the natural resources of the world. Food security is a critical issue for the survival of life on earth.
If the productivity of crops can be increased, it will have a significant positive impact on the sustainability of life.
Photosynthesis is a magnificent process of nature. However, there is a flaw in the process, or maybe nature intended it to be that way.
The oxygen and carbon dioxide molecules are similar in size and shape. An enzyme by the name of RuBisCO in plants is used to harvest carbon dioxide.
At times, this enzyme harvests an oxygen molecule mistaking it for a carbon dioxide molecule. The harvesting of oxygen molecules instead of carbon dioxide is putting a strain on the energy and resources of plants.
With global warming, the temperature of the earth is increasing. With the increase in temperature, the RubisCO is getting more prone to errors. Water also evaporates faster in increased temperatures.
This is straining the ecosystem of plants around the globe. As the RubisCO enzyme gets limited carbon dioxide, it depletes the energy of the plant is trying to harvest oxygen.
Some plants have evolved to handle this issue by pushing extra carbon dioxide to the RubisCO enzyme. This is like a turbocharged version of photosynthesis.
Plants that can do this are categorized as C4 plants. These plants can be highly effective in hot and dry weather, but as the global climate gets hotter, more of such plants will be seen everywhere.
At the moment, only 3% of the world’s flowering plants take the C4 route to photosynthesis. However, this 3% of the plants account for 24% of the world’s plant primary productivity in the world.
The type of plants mostly using the C4 pathway includes corn and sorghum. If somehow, other productive crops such as rice use the C4 pathway to photosynthesis, it can have an immense impact on the economics and food security of the world.