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Functional Significance of Respiration: Why It Matters in Life

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How Respiration Supports Survival and Energy in Animals

What is Respiration?

The cell is the basic unit of life in our body. They carry out almost all the functions in the body such as nutrition, excretion, transport, and reproduction. To perform all these functions, cells require energy. This energy is provided by the food that we eat. The food has energy stored in it in the form of various macromolecules. This energy is released by the process of respiration. For respiration, we breathe in oxygen. The oxygen we inhale is transported to different parts of the body and ultimately the cells. Inside the cells, oxygen helps in the breakdown of food consequently releasing energy. This process of breakdown of food to obtain energy is known as cellular respiration.

Thus, to perform various activities energy is required. The energy is acquired by the process of respiration which is obtained by the breakdown of food.


Why Do We Respire?

We respire to live by obtaining energy and other necessary gases, heat, which are crucial for the survival of a being. Our body is in constant need of oxygen. It is the major element that brings about the breakdown of molecules. Inside the cells, the food is broken down into water and carbon dioxide with the help of oxygen.

  • When food is broken down in the presence of oxygen, the process is called aerobic respiration.

  • When the food is broken down in the body in the absence of oxygen, it is called anaerobic respiration.

During the process of manufacturing energy molecules- ATP, waste bi-products are generated within the cell. The gaseous waste generated during respiration is Carbon dioxide. This waste in the form of carbon dioxide is also expelled from the body by the process of respiration.


Respiratory Organs of the Animals

Humans have a specialized and highly developed organ system for respiration that comprises the lungs. But various other animals respire through various other respiratory organs, which we will discuss in detail.

Respiration is a process of exchanging gases and it remains similar in all organisms. Ode of respiration could be external or internal, or it may be aerobic or anaerobic. Following are the classes of organisms depending on their mode of respiration-


1. Respiration through Plasma Membrane

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All unicellular organisms respire through their plasma membrane. In these organisms, the exchange of gases takes place through the surface of the cell. They take in oxygen from the surrounding and give out carbon dioxide from the cell surface or the plasma membrane by the process of diffusion. 

Example- Amoeba

 

2. Respiration through Skin

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Tapeworms, earthworms, and leeches respire through their skin. The skin of Earthworms is very thin and moist and many blood cells are spread on this skin. These blood cells are also known as capillaries. These capillaries carry out the gaseous exchange. This is why earthworms die of suffocation when their skins dry up.

 

3. Respiration through Trachea

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In some insects, the transportation of gases or the gaseous exchange takes place with the help of special fine tubes called tracheae. Oxygen enters through spiracles into the tracheal tubes, diffuses into the body tissue, and reaches every cell in the body. Finally, the Carbon dioxide released from the cells goes into the tracheal tubes and comes out through spiracles. 

Examples- Cockroaches, grasshoppers, etc.

 

4. Respiration through Gills

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Most of the aquatic animals like fish and prawns breathe through special respiratory organs called gills. Gills are projections of the skin that contain blood vessels that help in the exchange of gases. They take up the oxygen dissolved in water. To carry out respiration, fishes gulp water through the mouth and pump it over the gills. Through the gill slits, water passes into the gill chamber and in each chamber, the water passes over the filaments. They absorb oxygen from the water and replace it with carbon dioxide.

 

5. Respiration in Amphibians

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Amphibians are peculiar organisms; they use more than one organ of respiration during their lifecycle. They have gills in their tadpole phase for respiration and as they mature, they respire through lungs as well as skin. 

Example- Frogs.

 

6. Respiration through Lungs

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Many mammals, amphibians, and birds respire through lungs. Lungs are air-filled sac-like structures in the chest cavity that are connected to the outside by a series of tubes and small openings.

Example- Humans, birds, monkeys, etc.

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FAQs on Functional Significance of Respiration: Why It Matters in Life

1. What is the main functional significance of respiration?

The primary significance of respiration is to produce energy for the body's cells. Through this process, the chemical energy stored in food molecules like glucose is converted into a usable form called ATP (adenosine triphosphate). This energy powers all essential life activities, from muscle movement to cell growth and repair.

2. Why do all living organisms, from bacteria to humans, need to respire?

All living organisms are made of cells that require a constant supply of energy to stay alive and perform their functions. Respiration is the universal process that releases this vital energy from nutrients. Without respiration, cells cannot function, leading to the death of the organism. It is a fundamental process for sustaining life itself.

3. What are the key functions of the human respiratory system?

The respiratory system has several crucial functions beyond just breathing. These include:

  • Gaseous Exchange: Supplying oxygen to the blood and removing carbon dioxide from it.
  • Energy Production: Providing the oxygen needed for cellular respiration to create ATP.
  • pH Regulation: Helping to maintain the acid-base balance in the blood by managing carbon dioxide levels.
  • Vocalization: Allowing for speech and sound production as air passes over the vocal cords.
  • Protection: Filtering out dust, pollen, and other harmful particles from the inhaled air.

4. What are the main parts of our respiratory system and what do they do?

The main parts include the nose, pharynx, larynx, trachea, bronchi, and lungs. Air enters through the nose, where it is warmed and filtered. It then passes through the trachea (windpipe) into two bronchi, which lead to the lungs. Inside the lungs, the bronchi branch into smaller tubes ending in tiny air sacs called alveoli. It is in the alveoli where the exchange of oxygen and carbon dioxide with the blood happens.

5. How is the act of breathing different from cellular respiration?

This is a common point of confusion. Breathing (or ventilation) is a physical process of inhaling oxygen and exhaling carbon dioxide. It is the mechanism that brings air into the lungs. Cellular respiration, on the other hand, is a chemical process that occurs inside every cell of the body. It uses the oxygen supplied by breathing to break down glucose and release energy (ATP).

6. Why do our body’s cells specifically need oxygen from respiration?

Our cells use oxygen for aerobic respiration, which is the most efficient way to extract energy from food. Oxygen acts as the final electron acceptor in a series of chemical reactions within the mitochondria. This process generates a large amount of ATP. Without oxygen, cells can only perform anaerobic respiration, which produces far less energy and is not sustainable for complex organisms like humans.

7. Why does our breathing rate increase when we exercise?

When you exercise, your muscles work harder and require significantly more energy. To meet this demand, your cells need to perform cellular respiration at a much faster rate. This requires more oxygen and produces more carbon dioxide as a waste product. Your brain detects the rise in carbon dioxide, signaling your respiratory system to increase the breathing rate to supply more oxygen and expel the excess carbon dioxide quickly.

8. What is the functional difference between aerobic and anaerobic respiration?

The key functional difference lies in the use of oxygen and energy output. Aerobic respiration occurs in the presence of oxygen and breaks down glucose completely, releasing a large amount of energy (about 38 ATP molecules). Anaerobic respiration occurs without oxygen and only partially breaks down glucose, releasing a much smaller amount of energy (only 2 ATP molecules) and producing byproducts like lactic acid.