Aerobic and Anaerobic Respiration in Plants | Agriculture Optional Notes for UPSC PDF Download

Aerobic and Anaerobic Respiration

What is Aerobic Respiration?

As previously mentioned, cellular respiration comes in two forms: aerobic and anaerobic. Aerobic, which means "with air," refers to the cellular respiration process that utilizes oxygen to generate energy from food. This type of respiration is prevalent in most living organisms, including plants and animals, such as humans, birds, and other mammals.

During the act of breathing, we inhale oxygen-rich air and exhale air enriched with carbon dioxide. When we breathe in, the oxygen within the air is distributed throughout our body, eventually reaching each cell. Inside these cells, food containing glucose is broken down into carbon dioxide and water, facilitated by the presence of oxygen. This breakdown of food particles releases energy, which is then harnessed by our bodies to support growth. The energy generated through aerobic respiration contributes to the growth of both plants and animals, including humans.

This process can be succinctly described by the following equation:

Glucose + Oxygen → Carbon dioxide + Water + Energy

Aerobic respiration is a continuous and ongoing process that occurs within the cells of both animals and plants at all times.

What is Anaerobic Respiration?

Anaerobic respiration, as the name suggests, is the form of cellular respiration that operates without the use of oxygen to generate energy. In certain situations, some organisms face a shortage of oxygen but still require energy to survive. In the absence of oxygen, these organisms engage in anaerobic respiration to produce the necessary energy. This process is typically observed in lower plants and microorganisms. In the absence of oxygen, glucose derived from food is metabolized into alcohol and carbon dioxide, resulting in the release of energy.

The equation representing anaerobic respiration is as follows:

Glucose → Alcohol + Carbon dioxide + Energy

Additionally, multi-cellular organisms, including humans, resort to anaerobic respiration as a temporary response to oxygen-deficient conditions, such as during intense physical activities like running, sprinting, cycling, or weightlifting. When our body demands a high energy output and the oxygen supply is limited, muscle cells within our body shift to anaerobic respiration to meet the energy requirements.

Have you ever experienced muscle cramps during strenuous exercise or wondered why you feel discomfort after intense physical activity? Anaerobic respiration is often the culprit behind these cramps. Muscle cells engage in anaerobic respiration due to the lack of oxygen, resulting in a partial breakdown of glucose and the production of lactic acid. The accumulation of lactic acid is responsible for muscle cramps. This is why taking a hot shower after intense sports can alleviate cramps, as it improves blood circulation in the body, enhancing the supply of oxygen to the cells.

The equation representing the production of energy through anaerobic respiration, with the formation of lactic acid, is as follows:

Glucose → Lactic acid + Energy

It's important to note that anaerobic respiration generates a relatively smaller amount of energy compared to aerobic respiration because glucose is not fully broken down in the absence of oxygen.

Difference Between Aerobic and Anaerobic Respiration

The primary difference between aerobic and anaerobic respiration is the presence or absence of oxygen during the processes.
More detailed differences between the two are as follows:
However, it is a misconception that humans and other multicellular organisms use only aerobic respiration. This is disproven by the fact that our muscles, during vigorous exercises, undergo anaerobic respiration, where lactic acid is produced as the waste byproduct instead of carbon dioxide.

Conclusion

The primary distinction between aerobic and anaerobic respiration lies in the role of oxygen in cellular respiration. Aerobic respiration, as the name implies, is the method through which cells generate energy using oxygen. In this process, carbon dioxide and ATP, which serves as the energy currency of cells, are produced as by-products. In contrast, anaerobic respiration is similar to aerobic respiration but occurs in the absence of oxygen. Consequently, the by-products of anaerobic respiration are lactic acid and ATP.
It is important to note that contrary to common belief, multicellular organisms, including humans, employ anaerobic respiration to produce energy, but this only occurs when muscles do not receive sufficient oxygen during highly strenuous activities.