Q2. List the different types of respiration based on its location. How are these types of
respiration different from each other?
Answers
Respiration is the process in which organisms exchange gases between their body cells and the environment. From prokaryotic bacteria and archaeans to eukaryotic protists, fungi, plants, and animals, all living organisms undergo respiration. Respiration may refer to any of the three elements of the process.
Types of Respiration: External and Internal
Breathing Diagram
When inhaling, the diaphragm contracts and the lungs expand, pushing the chest upwards. When exhaling the diaphragm relaxes and the lungs contract, moving the chest back down.
wetcake/DigitalVision Vectors/Getty Images
External Respiration
One method for obtaining oxygen from the environment is through external respiration or breathing. In animal organisms, the process of external respiration is performed in a number of different ways. Animals that lack specialized organs for respiration rely on diffusion across external tissue surfaces to obtain oxygen. Others either have organs specialized for gas exchange or have a complete respiratory system. In organisms such as nematodes (roundworms), gases and nutrients are exchanged with the external environment by diffusion across the surface of the animals body. Insects and spiders have respiratory organs called tracheae, while fish have gills as sites for gas exchange.
Humans and other mammals have a respiratory system with specialized respiratory organs (lungs) and tissues. In the human body, oxygen is taken into the lungs by inhalation and carbon dioxide is expelled from the lungs by exhalation. External respiration in mammals encompasses the mechanical processes related to breathing. This includes contraction and relaxation of the diaphragm and accessory muscles, as well as breathing rate.
Internal Respiration
External respiratory processes explain how oxygen is obtained, but how does oxygen get to body cells? Internal respiration involves the transportation of gases between the blood and body tissues. Oxygen within the lungs diffuses across the thin epithelium of lung alveoli (air sacs) into surrounding capillaries containing oxygen depleted blood. At the same time, carbon dioxide diffuses in the opposite direction (from the blood to lung alveoli) and is expelled. Oxygen rich blood is transported by the circulatory system from lung capillaries to body cells and tissues. While oxygen is being dropped off at cells, carbon dioxide is being picked up and transported from tissue cells to the lungs.
Cellular Respiration
Cellular Respiration
The three processes of ATP production or celluar respiration include glycolysis, the tricarboxylic acid cycle, and oxidative phosphorylation. Credit: Encyclopaedia Britannica/UIG/Getty Images
The oxygen obtained from internal respiration is used by cells in cellular respiration. In order to access the energy stored in the foods we eat, biological molecules composing foods (carbohydrates, proteins, etc,) must be broken down into forms that the body can utilize. This is accomplished through the digestive process where food is broken down and nutrients are absorbed into the blood. As blood is circulated throughout the body, nutrients are transported to body cells. In cellular respiration, glucose obtained from digestion is split into its constituent parts for the production of energy. Through a series of steps, glucose and oxygen are converted to carbon dioxide (CO2), water (H2O), and the high energy molecule adenosine triphosphate (ATP). Carbon dioxide and water formed in the process diffuse into the interstitial fluid surrounding cells. From there, CO2 diffuses into blood plasma and red blood cells. ATP generated in the process provides the energy needed to perform normal cellular functions, such as macromolecule synthesis, muscle contraction, cilia and flagella movement, and cell division.
Aerobic Respiration
Aerobic cellular respiration
This is diagram of aerobic cellular respiration including glycolysis, Krebs cycle (citric acid cycle), and the electron transport chain. RegisFrey/Wikimedia Commons/CC BY-SA 3.0
Aerobic cellular respiration consists of three stages: glycolysis, citric acid cycle (Krebs Cycle), and electron transport with