Photosynthesis is one of the primary sources of energy for living organisms. The fossilized photosynthetic fuels account for almost 90% of the energy in the world (Johnson, 2016). Cellular respiration is a process that takes place in the living organism and converts nutrients into energy. This essay will examine photosynthesis and cellular respiration separately and identify similarities, differences, and interconnectedness between two processes. Two processes are similar in that they both deals with energy, but they are different because one process involves catabolic reactions and another anabolic one.
The purpose of photosynthesis is to convert atmospheric carbon dioxide into carbohydrates using light energy. The light splits one of the reactants, water in the mesophyll of the leaf into oxygen, electrons, and protons during the light-dependent phase (Johnson, 2016). Then carbon dioxide enters the mesophyll of the leaf through openings, stomata, during the light-independent phase. These two reactions differ in light utilization and molecules production. The first reaction products are oxygen, adenosine triphosphate (ATP), and nicotinamide adenine dinucleotide phosphate (NADPH) that are used as energy storages, while by the end of the second reaction, the carbohydrate is obtained, and molecules mentioned above are used (Flügge et al., 2016). Photosynthesis occurs in the chloroplast with the light-dependent reaction taking place in the thylakoid membrane, and light-independent reaction in the stroma. The energy produced in the light reaction is used to fix carbon dioxide and produce carbohydrates while oxygen is released outside. According to the following equation of the photosynthesis, C → O2 + 2H20 + photons (CH2O)n + electrons + O2 carbon monoxide and water are transferred into carbohydrates under the light with the release of atmospheric oxygen.
The purpose of cellular respiration is to convert nutrients into energy. The reactants of the respiration are glucose circulating in the blood and oxygen obtained from breathing, while the product is ATP. Cellular respiration starts from glycolysis in the mitochondria’s stroma, where the glucose is broken down into pyruvate (Bentley & Connaughton, 2017). Then it continues with the citric acid cycle that generates ATP, NADH, and FADH2. In the final stage, the electron transport chain uses these molecules to generate more ATP. The energy produced is then used for metabolic processes in the organism, while carbon dioxide is released with breathing (BBC Bitesize, n.d.). According to the following equation of the cellular respiration, C → 6H12O6 + 6O2 6CO2 + 6H2O the glucose is broken down into carbon dioxide and water with the presence of oxygen.
There are two main differences between photosynthesis and cellular respiration. The first one is the anabolic process, during which complex compounds are synthesized, while the second one is catabolic, which involves breaking down the compounds (Panawala, 2017). The second crucial difference is that photosynthesis is found only in chloroplasts, while cellular respiration is found in any living cell, making it a universal process. There are also two main similarities between photosynthesis and respiration. The first similarity is that both processes involve the production of ATP (Stauffer et al., 2018). The second similarity is that both processes utilize ATP but for different purposes.
Photosynthesis and cellular respiration are connected in such a way that they allow to perform metabolic functions normally. Moreover, these processes help to regulate the concentration of oxygen and carbon dioxide in the atmosphere. If photosynthesis stopped occurring, the level of oxygen would drop dramatically This would lead to deaths of all living organisms whose lives depend on this molecule. Whereas if cellular respiration stopped happening, living creatures would not be able to generate energy and sustain life.
To conclude, photosynthesis plays a crucial role in maintaining life on Earth. Photosynthesis uses light energy to produce oxygen, while cellular respiration uses oxygen to break down complex molecules and provide energy. These processes are different in their metabolic nature, but similar in terms of energy storage. If photosynthesis did not exist, the life for oxygen-dependent creatures would become extinct. Similarly, in the case of cellular respiration disappearing, living organisms would not be able to produce energy.
References
BBC Bitesize. (n.d.). Respiration. 2020. Web.
Bentley, M., & Connaughton, V, P. (2017). A simple way for students to visualize cellular respiration: Adapting the board game MousetrapTM to model complexity. CourseSource. 4, 1-6. Web.
Flügge, W., Westhoff, P., & Leister, D. (2016). Recent advances in understanding photosynthesis. F1000 Research, 5, 1-10.
Johnson, M. P. (2016). Photosynthesis. Essays Biochemistry, 60(3), 255-273.
Panawala, L. (2017). Difference between photosynthesis and respiration. IE PEDIAA. Web.
Stauffer S., Gardner A., Ungu D.A.K., López-Córdoba A., & Heim M. (2018). Cellular respiration. In Labster virtual lab experiments: Basic biology (pp. 43-55). Springer.