Respiration
The biological process by which living things exchange gases with their surroundings, usually including the intake of oxygen and the emission of carbon dioxide, is referred to as respiration.There are two main types of respiration: cellular respiration and respiratory system respiration.
Both the respiratory system’s mechanisms for gas exchange and cellular respiration occurring within mitochondria are involved in respiration in both humans and many other animals. Carbon dioxide is released through the respiratory system as a consequence of cellular respiration, which uses oxygen from the air to create energy. Together, the respiratory and circulatory systems circulate gases, supplying cells with the oxygen they require and eliminating waste carbon dioxide.
Respiration in plants
In plants, respiration involves the exchange of gases, much like in animals, but with some differences in the process. Plant respiration occurs at both the cellular and organismal levels.
Cellular Respiration in Plants
Plant cells use a process called cellular respiration to break down organic molecules like glucose and make ATP (adenosine triphosphate), which is used as energy. For many different cellular functions and activities, this energy is essential. With a few notable exceptions relating to plant cellular architecture, the general mechanism of cellular respiration in plants is comparable to that in mammals.
The process of cellular respiration in plants occurs in three main stages: glycolysis, the citric acid cycle (Krebs cycle), and the electron transport chain.
Glycolysis:
- Location: Glycolysis takes place in the cytoplasm of plant cells.
- Process: Glucose, a six-carbon sugar, is broken down into two molecules of pyruvate. This process yields a small amount of ATP and NADH (nicotinamide adenine dinucleotide), which are energy carriers.
Citric Acid Cycle (Krebs Cycle):
- Location: The citric acid cycle occurs in the mitochondria of plant cells.
- Process: Each pyruvate from glycolysis is further broken down in the citric acid cycle, releasing carbon dioxide. The cycle generates additional ATP, NADH, and FADH2 (flavin adenine dinucleotide), which are high-energy molecules.
Electron Transport Chain:
- Location: The electron transport chain is located in the inner mitochondrial membrane of plant cells.
- Process: NADH and FADH2 produced in glycolysis and the citric acid cycle donate electrons to the electron transport chain. As electrons move through the chain, energy is released and used to pump protons across the membrane, creating a proton gradient. This gradient is used to generate ATP through a process called chemiosmosis.
It’s crucial to remember that during photosynthesis, water, carbon dioxide, and sunshine are used by plants to create glucose. Cellular respiration, on the other hand, uses glucose as fuel and generates carbon dioxide and water. Plant cells use and produce energy in a balanced manner because to the interconnection of these two processes, photosynthesis and cellular respiration.
Organismal Respiration in Plants
In plants, exchange of gases with their surroundings occurs at the level of the entire plant during the process of cellular respiration. In order for the plant to produce carbon dioxide as a byproduct and get the oxygen required for cellular respiration, this exchange is necessary.
There are several processes involved in organismal respiration in plants:
Stomatal Respiration:
- Stomata: Tiny pores called stomata are present on the surface of leaves, stems, and sometimes other plant parts. Stomata regulate the exchange of gases between the plant and the atmosphere.
- Daytime: During the day, stomata open to allow the entry of carbon dioxide, which is essential for photosynthesis. However, this opening also allows some oxygen to escape, contributing to a form of respiration called stomatal respiration.
Lenticular Respiration:
- Lenticels: Lenticels are small openings in the bark of woody plants. They provide a pathway for gas exchange between the inner tissues of the plant and the external environment.
- Gas Exchange: Through lenticels, plants can exchange gases, including oxygen uptake for respiration and the release of carbon dioxide produced during cellular respiration.
Root Respiration:
- Roots: The roots of plants are actively involved in gas exchange and respiration. They take up oxygen from the soil, which is crucial for the metabolic processes occurring in root cells.
- Release of Carbon Dioxide: As a result of cellular respiration in root cells, carbon dioxide is released into the soil.
Together, these mechanisms support plants’ total organismal respiration. Different plant tissues depend on the intake of oxygen and the emission of carbon dioxide for their metabolic processes. While plants can make their own food (glucose) through photosynthesis, which uses light, carbon dioxide, and water, respiration is required to release ATP for cellular processes and to break down this stored energy.
It’s vital to remember that a plant’s rates of photosynthesis and respiration can change based on a variety of conditions, including temperature, light availability, and metabolic requirements.
                In summary, plant respiration involves both cellular respiration within individual cells and the exchange of gases at the organismal level through structures like stomata, lenticels, and roots. While plants are capable of photosynthesis to produce their own food, they still require respiration to break down the produced organic molecules and release energy for various metabolic processes.
Respiration reaction
The overall chemical equation for aerobic cellular respiration, which is the most common form of respiration in both plants and animals, is as follows
This equation, expressed in words, shows how oxygen and glucose, a carbohydrate, combine to generate carbon dioxide, water, and energy. When glucose is broken down in the presence of oxygen, energy is released that is utilized by cells for a variety of biological processes. The citric acid cycle, the electron transport chain, and glycolysis are some of the phases that make up the more intricate and multi-stage real process of cellular respiration.
Although this equation depicts aerobic respiration, other species, such as some bacteria and some cells in animals and plants, may experience anaerobic respiration in the absence of oxygen. Depending on the organism, lactic acid or ethanol are frequent results of anaerobic respiration. The final products of this process might vary.