Boy student demonstrates the principle of photosynthesis

Do Plants 'Breathe'?

Excerpted from BYJU'S: The Learning Shop

Excerpted from Difference between Photosynthesis and Respiration

Yes, like animals plants also breathe.

All living organisms, including plants, receive their energy required for their survival from a chain of chemical reactions called respiration.

Most oxygen comes from tiny ocean plants called phytoplankton that live near the water’s surface. Like all plants, they photosynthesize by using sunlight and carbon dioxide to make food. A by-product of photosynthesis is oxygen.

First, the Basics!

Plant Respiration

Respiration is a process that helps in converting the oxygen taken from the environment by plants and glucose present in the body into Carbon Dioxide and water.

The carbon dioxide is released back into the environment and the water is utilized by the bodies of these living organisms.

Plant Photosynthesis

Photosynthesis is the process by which green plants make food for themselves. The process of photosynthesis is restricted to green plants only because of the presence of chlorophyll in the plant cells.

In this process, the leaves of the green plants trap sunlight with the help of an element present in them called chlorophyll. The plants make use of this trapped sunlight and water to create energy. The reaction takes place in the leaves of the green plants.

Graphic showing difference between photosynthesis and respiration.

  Difference Between Photosynthesis and Respiration

Respiration and Photosynthesis are two different processes that aim to create energy in living organisms. While respiration takes place in humans and animals, photosynthesis takes place in green plants. These processes are essential for carrying out energy manufacturing in living organisms. The difference between both the processes is as follows:

The process of respiration includes all the living organisms while the process of photosynthesis takes place in green plants only.

Photosynthesis requires chlorophyll as a major element to carry out its process. Whereas, respiration requires no chlorophyll.

The end products in respiration are Carbon dioxide, water, and energy ATPs (Adenosine Triphosphates).

Respiration takes place throughout the day and night. However, the process of photosynthesis takes place in the presence of sunlight. Thus, it can take place during the day only.

Respiration requires oxygen and photosynthesis requires carbon dioxide to take out their respective processes.

Photosynthesis is dependent upon the availability of sunlight, while respiration doesn’t require sunlight.

The energy during photosynthesis is stored in the form of starch and carbohydrates - glucose. The energy during respiration is stored in the cells of the living organisms.

  Oxygen and Carbon Dioxide In Photosynthesis

Plants use photosynthesis to capture carbon dioxide. Carbon dioxide is NOT released during photosynthesis, but small amounts of that gas are emitted both day and night as a by-product of cellular respiration.

The majority of plants absorb carbon dioxide during the day for photosynthesis and do so in greater amounts than they release for cellular respiration.

Plants also release oxygen into the atmosphere through photosynthesis.

Plants do require oxygen for respiration which in return gives out carbon dioxide. Unlike animals, plants do not have any specialized structures for gaseous exchange but they have stomata (present in leaves) and lenticels (present in stems) which are involved in the exchange of gases. Compared to animals and humans, plant roots, stems, and leaves respire at a very lower rate.

Graphic of respiration in plants

In this process of cellular respiration, plants produce glucose molecules through photosynthesis process by capturing the solar energy and converting it into glucose. There are many live experiments to prove that plants do breath. All plants do respire to provide energy for their cells to stay active or alive.

  The Process of Respiration

Graphic of leaf stomata.

During respiration, very little amount of gas exchanges takes place within the different parts of the plants. Therefore, each part takes care of its own energy requirements.

Roots, stems, and leaves of plants exchange gases for respiration separately. As we all know, leaves have tiny pores called stomata, which is used for the exchange of gases. The oxygen, taken in through stomata is used by cells in the leaves to break down glucose into carbon dioxide and water.

  The Role of Air Temperature

Plant respiration occurs 24 hours per day, but night respiration is more evident since the photosynthesis process ceases. During the night, it is very important that the temperature is cooler than during the day because plants can experience stress. As the night time temperature increases, the respiration rate increases and consequently plant's temperature increases. This action could result in flower damage and poor plant growth.

  Respiration in Roots

Roots, the underground part of the plants absorb air from the air spaces present between the soil particles. Thus, the oxygen absorbed through roots is used to release energy which is later utilized for the transportation of minerals and salts from the soil.

Graphic of respiration in roots

We are aware of the fact that plants have the unique ability to photosynthesize. Photosynthesis is the process by which plants prepare their own food. It takes place only in the parts of plants that contain chlorophyll, i.e. only in the green parts of the plants. The process of photosynthesis is so prominent that it sometimes masks the process of respiration in plants. However, we must know that respiration in plants occurs throughout the day while photosynthesis process takes place only in the presence of light. Therefore, at night the respiration in plants becomes prominent.

That is why we often hear that people are asked not to sleep under a tree at night. This may cause suffocation due to the excessive presence of carbon dioxide released by trees as a result of respiration.

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  Respiration in Stems

In the case of the stem, the air gets diffused in the stomata and passes through various parts of the cell for respiration. The carbon dioxide produced during this stage also diffuses through the stomata. In higher plants or woody plants, the gaseous exchange is carried out by lenticels.

  Respiration in Leaves

Leaves comprise tiny pores referred to as stomata. The exchange of gases takes place via stomata through the process of diffusion. Each stoma is controlled by Guard Cells. The opening and closing of the stoma help in the exchange of gases between the atmosphere and the interior of leaves.

Read More: How Leaves Work
Graphic of respiration in leaves

  Types of Respiration

Aerobic Respiration

This type of respiration takes place in the mitochondria of all eukaryotic entities. Food molecules are completely oxidized into the carbon dioxide, water, and energy is released in the presence of oxygen. This type of respiration is observed in all the higher organisms and necessitates atmospheric oxygen.

Anaerobic Respiration

This type of respiration occurs within the cytoplasm of prokaryotic entities such as yeast and bacteria. Here, lesser energy is liberated as a result of incomplete oxidation of food in the absence of oxygen. Ethyl alcohol and carbon dioxide are produced during anaerobic respiration.

Chlorophyll A pigment that gives plants their green color, and it helps plants create their own food through photosynthesis.
Cytoplasm Cytoplasm is a thick solution that fills each cell and is enclosed by the cell membrane.
Epidermis The outermost, layer of cells covering the stem, root, leaf, flower, fruit, and seed parts of a plant.
Eukaryotic Cells that contain a well-defined nucleus. They include protozoans, algae, fungi, plants, and animals.
Guard Cells Crescent-shaped cells that surround a stoma in the epidermis. Changes in the swelling of the cells cause the opening and closing of the stoma.
Lenticel Raised pores in the stem of a woody plant that allows gas exchange between the atmosphere and the internal tissues.
Mitochondria Mitochondria are organelles within eukaryotic cells that produce the main energy molecule used by the cell.
Photosynthesis The process by which green plants and certain other organisms transform light energy into chemical energy.
Prokaryotic Cells lack a “true nucleus”. They include yeast and bacteria.

Further Information:

 Wisconsin Native Fruit Trees
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 Use Eggshells For Your Plants
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