Cellular Respiration

All living organisms need energy in order to survive, grow, and be active. For humans and many other creatures, this energy comes from a process called cellular respiration. Cellular respiration is the way our cells break down food molecules, such as glucose, to contribute to the release of energy in the molecular form of Adenosine Triphosphate (ATP). 

The primary reactants in cellular respiration are glucose and oxygen. Glucose and oxygen enter the cell and go through several chemical changes that release energy. The main products of this process are carbon dioxide, water, and ATP energy. As seen from the diagram above, this process can be summarized as the following equation: glucose plus oxygen produces carbon dioxide, water, and ATP.

There are two main types of cellular respiration, which are aerobic and anaerobic. Aerobic respiration, like its name, means “with oxygen” and this process occurs when there is enough oxygen available in our cells. It is considered to be the most efficient form of respiration since it can produce the largest amount of ATP that can be used for our body. The mitochondria in our muscle cells combine glucose and oxygen to produce carbon dioxide, water, and ATP energy. It allows our muscles to work efficiently by supplying them with the energy they need. In aerobic respiration, glucose is fully broken down in the presence of oxygen, releasing carbon dioxide and water as the waste products.

However, our bodies sometimes face situations where oxygen is not available in sufficient amounts. This occurs most often during intense exercise, when the muscles require energy faster than oxygen can be delivered. When there is not enough oxygen available, the mitochondria cannot carry out aerobic respiration. Therefore, cells switch from aerobic respiration to anaerobic respiration. Anaerobic respiration is a process of cellular respiration that produces ATP energy without oxygen. In this case, glucose is only partially broken down. Additionally, it produces not only carbon dioxide and water as the waste products but it also produces lactic acid. Lactic acid can build up in the muscles and cause muscle fatigue or pain. Anaerobic respiration produces much less ATP than aerobic respiration, but it is a quick way for cells to get energy when oxygen supply is limited. 

In conclusion, cellular respiration is an essential process for life, as it provides the energy that cells and organisms need to survive. Aerobic respiration, which uses oxygen, allows the body to produce a large supply of ATP efficiently. On the other hand, anaerobic respiration offers a backup system that generates energy quickly even in situations where oxygen supply is not sufficient; however anaerobic respiration results in lactic acid buildup and muscle fatigue. Together, these two forms of respiration ensure that humans and other organisms always have the access to energy, whether they are resting calmly, walking or during intense physical activity. 

Works Cited

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Monash University. “Cellular Respiration.” Student Academic Success, 10 Jan. 2025, www.monash.edu/student-academic-success/biology/cellular-respiration.

National Geographic. “Cellular Respiration | National Geographic Society.” Education.nationalgeographic.org, 20 May 2022, education.nationalgeographic.org/resource/cellular-respiration-infographic/.

Science Direct. “Cellular Respiration - an Overview | ScienceDirect Topics.” Sciencedirect.com, 2015, www.sciencedirect.com/topics/neuroscience/cellular-respiration.

Tarantino, Corinne. “Cellular Respiration: What Is It, Its Purpose, and More.” Osmosis, Elsevier, 2022, www.osmosis.org/answers/cellular-respiration.