Oxygen and Carbon Dioxide Cycle: Definition, Significance, Steps

Oxygen and Carbon Dioxide Cycle: The Earth’s atmosphere is made up of a mixture of gases, out of which oxygen makes up \(21\%\) and carbon dioxide \(0.03\%\) of the Earth’s atmosphere. The Earth’s crust acts as the largest oxygen reservoir, most of which is bound to minerals and are unavailable. Among all the uncombined elements in the atmosphere, oxygen is second only to nitrogen in abundance. All living beings use oxygen to respire and return it to the air in the form of carbon dioxide. This process continues, and the oxygen and carbon cycle play an important role in maintaining the balance of nature. Let’s explore what these cycles are and how they affect our survival.

Oxygen Cycle

in the air and dissolved in water, oxygen makes up about \(30\%\) of the Earth’s crust and about \(21\%\) of the air in the Earth’s atmosphere.

The oxygen cycle is a biogeochemical cycle that explains the movement of oxygen gas within the ecosystem comprising the atmosphere, lithosphere and biosphere.

The oxygen cycle is a cyclic process in which oxygen element is circulated continuously through the living and non-living components of the biosphere.

Stages of the Oxygen Cycle

The steps involved in the oxygen cycle are:

Stage-1: By photosynthesis, all green plants absorb carbon dioxide gas from the atmosphere in the presence of sunlight to form carbohydrates and release oxygen into the atmosphere. The oxygen released is a byproduct of photosynthesis.

Stage-2: Through respiration, all aerobic organisms use up the oxygen available in the atmosphere to release carbon dioxide, water and energy.

Stage-3: All aerobic organisms take in oxygen and exhale Carbon dioxide back into the atmosphere during respiration. The plants use exhaled carbon dioxide to carry out the process of Photosynthesis. Oxygen is released and is used by living organisms. The cycle continues, and the level of oxygen and carbon dioxide is balanced within the atmosphere.

Stage-4: Combustion also contributes to the oxygen cycle. During combustion or burning, oxygen reacts with carbon to form carbon dioxide gas.

Importance of Oxygen Cycle

Oxygen is one of the essential components required for the existence of life on Earth. It is mainly required for:

1. Respiration
2. Photosynthesis
3. Combustion
4. Supporting aquatic life
5. Decomposition of organic waste

The oxygen cycle is mainly required to maintain the oxygen level in the atmosphere. To be brief, the oxygen cycle begins with plants through the process of photosynthesis in which green plants absorb the carbon dioxide present in the atmosphere in the presence of sunlight, releases oxygen into the atmosphere, which is consumed by all living beings through the process of respiration giving out carbon dioxide. The plants take up the carbon dioxide for the photosynthesis process, and the process continues.

Carbon Cycle

The most important constituent of all organic compounds, many of which are essential to life on the Earth, is carbon. The carbon source in living matter is carbon dioxide \(\left( {{\text{CO}}_2} \right)\) which is not only present in the air but is also dissolved in water.

The element carbon enters the ecosystem through the carbon cycle. Carbon moves from the atmosphere into the Earth and its organisms through the carbon cycle and then back again. It is nature’s way of reusing carbon atoms, which travel from the atmosphere into organisms in the Earth and then back into the atmosphere over and over again.

Carbon Cycle Steps

The steps involved in the process of the carbon cycle are as follows:

1. Earth’s atmosphere contains about \(0.035\%\) of carbon dioxide. Such a meagre amount of carbon dioxide acts as a carbon source for the green plants to conduct photosynthesis. During photosynthesis, green plants absorb the carbon dioxide present in the atmosphere into a biologically usable form of carbon, namely glucose.
2. Animals eat the leaves of these plants to fulfil their carbon needs and release carbon dioxide into the atmosphere by respiration.
3. During respiration, the glucose stored in plants is broken down, releasing carbon dioxide into the atmosphere.
4. When plants and animals die, their remains are decomposed by microorganisms liberating carbon dioxide into the atmosphere.
5. The burning of fossil fuels like coal and oil also adds up carbon dioxide to the atmosphere.

In the carbon cycle, Carbon dioxide is used up only in photosynthesis, which is approximately equal to the carbon dioxide given out by the process of respiration, decomposition and combustion. This helps to maintain the level of Carbon in nature.

Carbon Cycle on Land

Carbon enters the atmosphere through processes such as respiration, combustion and decomposition. Plants use up this carbon dioxide to produce Carbon-based compounds known as carbohydrates. The carbohydrates produced by the plants enter the food chain from the producers to consumers. The consumers give back the absorbed Carbon in the form of carbon dioxide through respiration.

Oceanic Carbon Cycle

Ecologically, oceans act as carbon sinks because they take in more Carbon than they give out. Marine animals convert Carbon to calcium carbonate, which is stored in their shells. When these organisms die, their body decomposes, leaving behind their hard shells. These shells accumulate on the seafloor and are eventually broken down by the waves and pressure into limestone.

On being exposed to air, the limestone weathers and the Carbon is released back into the atmosphere as carbon dioxide.

Importance of Carbon Cycle

Though it is present in trace amounts in the atmosphere, Carbon plays a vital role in balancing and trapping the Sun’s energy. Therefore, Carbon in the form of carbon dioxide acts like a blanket over the planet. Disturbing the carbon cycle will result in serious climatic consequences such as global warming.

Summary

As oxygen is vital to the existence of all life forms, Carbon dioxide is also important to carry out various life processes. The whole ecosystem depends on the balance of these two gases. The oxygen cycle and carbon cycle are responsible for maintaining a balance between these gases in the atmosphere. Both of these cycles are interdependent on each other to carry out essential life processes. In this article, we learned the oxygen and carbon cycle and their importance in the survival of life on Earth.

Frequently Asked Questions (FAQs)

Q.1. What are the steps of the carbon cycle?
Ans: The steps of the carbon cycle are photosynthesis, respiration, combustion and decomposition.

Q.2. What are the steps of the oxygen cycle?
Ans: The steps of the oxygen cycle are photosynthesis, respiration and combustion.

Q.3. Why is the carbon dioxide and oxygen cycle important?
Ans: The carbon dioxide and oxygen cycle are critical to life on Earth. Humans, and most other organisms, need oxygen to survive. In contrast, plants rely on animals for carbon dioxide to perform photosynthesis.

Q.4. Why is it important to maintain the oxygen and carbon dioxide levels in the atmosphere?
Ans: Maintaining the oxygen and carbon dioxide level in the atmosphere is important because plants and animals that are the building elements of an ecosystem depend on these two gases for their survival. Each makes what the other uses.

Q.5. How do oxygen and carbon dioxide gases balance in the atmosphere?
Ans: Plants take up carbon dioxide in the process of photosynthesis and give out oxygen. Humans, animals and plants require oxygen for respiration and give out carbon dioxide. This exchange of gases helps to maintain the balance in the atmosphere.

We hope this detailed article on the Oxygen and Carbon Dioxide Cycle helps you in your preparation. If you get stuck do let us know in the comments section below and we will get back to you at the earliest.