Photosynthesis and cellular respiration are energy reactions occurring in plant and animal cells. During photosynthesis, oxygen and glucose are produced from sunlight, water, and carbon dioxide. During cellular respiration, oxygen and glucose are used to create water, carbon dioxide and ATP. Both processes constitute the energy cycle required for organisms to function. The purpose of this paper is to analyze cellular respiration and photosynthesis and establish their similarities and differences.
Photosynthesis is the process in green plants that transforms solar radiation into energy that plants use for development and growth. It is basically a complex chemical reaction that happens inside the leaves of a plant, aimed to produce food for it to survive (Govindjee et al., 2018). The starting reactants are the light of the sun, carbon dioxide, and water. They get into the plant from the sun, air, and ground respectively. Photosynthesis occurs in chloroplasts in two stages: light-dependent reactions and the Calvin cycle.
During the first stage, chloroplasts capture sunlight and use it to form the molecules of ATP and NADPH. During the second stage, called the Calvin cycle, the energy generated during the first stage is used to make carbohydrates (Blankenship, 2014). Contrary to the first stage, the reactions of the Calvin cycle can occur without light. The overall process can be described as following: six molecules of carbon dioxide and six water molecules are converted in the presence of light into glucose and six molecules of oxygen. Glucose is used as an energy source for the plant, while oxygen is released back into the air.
Cellular respiration is a set of reactions that converts glucose into adenosine triphosphate (ATP), an organic compound that provides energy to cells. The purpose of the process is to produce energy that organisms need to function (Russell et al., 2016). The initial reactants are oxygen and glucose, with glucose entering the body with food, and oxygen entering the body when breathing. During cellular respiration, a glucose molecule is split into ATP, carbon dioxide, and water. The reactions occur in mitochondria in four stages: “glycolysis, pyruvate oxidation, citric acid cycle, and oxidative phosphorylation” (Campbell & Paradise, 2016, p. 124). The overall reaction can be described as one molecule of glucose and six molecules of oxygen yielding six molecules of carbon dioxide, six water molecules, and 36–38 molecules of ATP (Campbell & Paradise, 2016). Carbon dioxide is transported to the lungs to be exhaled, and ATP is used in cellular work.
Both photosynthesis and cellular respiration are processes aimed at converting one form of energy into another. They both involve the same ingredients: water, oxygen, carbon dioxide, and glucose. However, the processes are opposite in their products and reactants. Cellular respiration takes oxygen from the air, while photosynthesis puts it back. Photosynthesis needs light to operate, while cellular respiration takes place both day and night in living cells.
The two processes complement each other in a mutually beneficial relationship. They are both a part of the cycle of biochemical reactions in which one type of energy is converted into another. Both processes are required to support the being of plants and animals. If one of them stops occurring, the other would also be unable to continue because it requires the energy produced by the other (Russell et al, 2016). They both constitute a cycle that sustains life on Earth.
Photosynthesis and cellular respiration are different processes that are connected to one another. They are two sides of the energy circulation process that supports the life of every living organism on the Earth (Treagust & Tsui, 2013). Photosynthesis produces energy for plants and releases oxygen that animals use to create ATP. In the production of ATP, carbon dioxide is released that is used by plants to make oxygen. In can be said that photosynthesis and cellular respiration form a cycle that provide energy necessary for all life on the Earth.
References
Blankenship, R. (2014). Molecular mechanisms of photosynthesis. John Wiley & Sons.
Campbell, M., & Paradise, C. (2016). Cellular respiration. Momentum Press.
Govindjee, Bjorn, L., & Shevela, D. (2018). Photosynthesis: Solar energy for life. World Scientific Publishing.
Russell, P., Hertz, P., & McMillan, B. (2016). Biology: The dynamic science. Cengage Learning.
Treagust, D., & Tsui, C. (2013). Multiple representations in biological education. Springer Science & Business Media.