Daniela Casallas

Photosynthesis is not just about oxygen production Demands for food, materials, and energy in a world where the human population is rapidly growing have created a necessity to increase both the amount of photosynthesis and the efficiency of converting the photosynthetic output into products useful to people. But, what are the benefits of photosynthesis in addition to the production of oxygen? Photosynthesis is one of the most efficiently cycled and sustainable processes we know in nature. This deceivingly simple process forms the basis for all the energy sources essential to life, from the intake of food to the burning of fossil fuels, and more recently, for the industrial production of value-added chemicals or bio-energy.1     How photosynthesis works? Photosynthesis is a process by which green plants and certain other organisms transform light energy into chemical energy. During photosynthesis in green plants, light energy is captured and used to convert water, carbon dioxide, and minerals into oxygen and energy-rich organic compounds.2 First, one of the benefits of photosynthesis is the production of energy. One of the carbohydrates resulting from photosynthesis is cellulose, which makes up the bulk of dry wood and other plant material. When we burn wood, we convert the cellulose back to carbon dioxide and release the stored energy as heat. Energy from burning "biomass" is important in many parts of the world. For example, Ethanol (grain alcohol) produced from sugars and starches by fermentation is a major automobile fuel in Brazil and is added to gasoline in some parts of the United States to help reduce emissions of harmful pollutants. Ethanol is also readily converted to ethylene, which serves as a feedstock to a large part of the petrochemical industry.3 Additionally, our major sources of energy, of course, are coal, oil and natural gas. These materials are all derived from ancient plants, and animals, and the energy stored within them is chemical energy that originally came from sunlight through photosynthesis.2,3 Second, photosynthesis has an important role in the production of fiber and materials. Wood, of course, is not only burned, but is an important material for building and many other purposes. Paper, for example, is nearly pure photosynthetically produced cellulose, as is cotton and many other natural fibers. Even wool production depends on photosynthetically-derived energy. Many of our other materials needs are filled by plastics and synthetic fibers which are produced from petroleum, and are thus also photosynthetic in origin. Even much of our metal refining depends ultimately on coal or other photosynthetic products.3 Third, in the recent time, the study of plant and their photosynthesis could help improve some medical treatments. Light has a very high energy content, and when it is absorbed by a substance this energy is converted to other forms. When the energy ends up in the wrong place, it can cause serious damage to living organisms. Aging of the skin and skin cancer are only two of many deleterious effects of light on humans and animals. Because plants and other photosynthetic species have been dealing with light for eons, they have had to develop photoprotective mechanisms to limit light damage. Learning about the causes of light- induced tissue damage and the details of the natural photoprotective mechanisms can help us can find ways to adapt these processes for the benefit of humanity in areas far removed from photosynthesis itself.3 Finally, one of the greatest benefits that humans and animals receive from plants, our food. Because of their photosynthetic ability, plants are known as producers and are the base of nearly every food chain on Earth. (Algae are the equivalent of plants in aquatic systems). All of the energy that we eat comes from organisms that are photosynthetics, whether we eat these plants directly or whether we eat something that itself eats these plants, such as cows or pigs. Furthermore, Plants incorporate nutrients into their tissues via photosynthesis. Thus, plants and other photosynthetic organisms play vital roles in nutrient cycling. Nitrogen in the air is fixed in plant tissues and becomes available to create proteins. Micronutrients that are within soil matrices can also become incorporated into plant tissue and are available for herbivores farther up the food chain.4 The above examples illustrate the importance of photosynthesis as a natural process and the impact that it has on all of our lives. In conclusion, directly or indirectly, photosynthesis supplies all of our food, energy, and environmental requirements and many of our needs for fiber and building materials.      References 1. Janssen PJ, Lambreva MD, Plumeré N, et al. Photosynthesis at the forefront of a sustainable life. Front Chem. 2014;2:36. Published 2014 Jun 12. doi:10.3389/fchem-. Lambers, Hans and Bassham, James Alan. "Photosynthesis". Encyclopedia Britannica, https://www.britannica.com/science/photosynthesis. Accessed 10 February 2021. 3. Photosynthesis W. Why Study Photosynthesis | Center for Bioenergy & Photosynthesis. Live-bioenergy.ws.asu.edu. https://live-bioenergy.ws.asu.edu/content/why-study-photosynthesis. Published 2021. Accessed February 10, 2021. 4. Role of Photosynthesis in Nature. Sciencing. https://sciencing.com/role-photosynthesis-nature-.html. Published 2021. Accessed February 10, 2021.