Why Do Organisms Survive

Gas exchange in mammals is carried out through the lungs. But gas exchange actually occurs in the alveoli within the lungs.

This experiment was designed to identify the effect of cold-water temperatures on the respiration rate of goldfish. The respiration rates helped to identify the goldfish as being ectotherms or endotherms. Organisms exchange gases with their environment through a process called respiration or breathing. Aerobic respiration, also known as aerobic metabolism, occurs when oxygen is taken into the body and sent to all its cells; the oxygen is then used to break down food for energy (White and Campo 2008). Respiration can be experienced through several structures such as the lungs, tracheae, gills, and integument in order to obtain

The diaphragm separates the chest and the abdomen as well as this it has a large role in breathing. The diaphragm moves down when we breathe in which expands the chest cavity making room for air to enter through the nasal cavity or mouth. When we breathe out the diaphragm moves upwards, forcing the chest cavity to reduce in size and pushing the gases in the lungs up and out of either the nose or mouth.

Small air sacks called alveoli are at the tips of the bronchioles. When air reaches them, the oxygen concentration is high, which causes diffusion into red blood cells travelling through pulmonary capillaries (7). The red blood cells then distribute the new oxygen to the rest of the body. When they reach the alveoli again, they exchange carbon dioxide (a form of cell waste) for new oxygen, and repeat the process. The carbon dioxide is moved through the bronchioles, bronchi, and trachea in the form of exhalation.

Every living thing needs cellular respiration to survive. Cellular respiration is the process that releases energy by breaking down glucose and other food molecules in the presence of oxygen. This process happens through three distinct operations which are glycolysis, the Krebs cycle, and the electron transport chain. Throughout these cycles, our bodies turn oxygen and glucose into carbon dioxide, water, and energy. Although this system seems simple enough, cellular respiration can not take place in just one step because all of the energy from glucose would be released at once, most of it being lost in the form of light and heat. All this plays a very important role in our lives and without it, organisms would cease to exist.

The chthonic hypothesis, as proposed by J. Lighton , suggests that the discontinuous gas exchange system used has evolved to accommodate insects that live in hypoxic conditions for the large majority of their lives. It is plausible that the respiratory system of insects is not the most efficient at CO2 diffusion under normocapnic conditions (21% O2 in the atmosphere). This system consists of external valve like openings, called spiracles, that channel oxygen into the body and allow CO2 to exit. From the spiracle, oxygen is sent through a series of progressively narrowing tracheae and tracheoles, and is diffused directly into the tissue and cells. This process relies mainly on passive diffusion and therefor internal and external gas pressures. Emekci et al examined the respiratory patterns of Tribolium castaneum in environments with atmospheric oxygen contents of 1%, 2%, 3%, 5%, 10%, and 15%. In adult specimens, CO2 output was high at 3-10% O2, with a respiratory quotient of 1.18 at 5%. This can be compared to the respiratory quotient of 0.88 observed at 21% O2. This research supports the theory that normocapnic conditions are not the optimal conditions for the respiratory system of insects to function under due to its designs that relies on environmental gas pressures and concentrations to facilitate

Gaseous exchange takes place in the millions of alveoli located in the lungs. These alveoli are surrounded by blood capillaries so that the oxygen is able to pass from the alveoli into the bloodstream so it can then be carried by the red blood cells throughout the body. Similarly, the carbon dioxide from the bloodstream is able to pass through into the alveoli so it can then be exhaled. This process is made possible due to the concentration gradient of the gases across the gas exchange surfaces.

Within the alveoli, the oxygen is transferred to the blood whilst simultaneously collecting waste carbon dioxide for excretion as we breath out. This transference is known as diffusion and is linked to the cardiovascular system.

2. The exchanges of gas begins with the diffusion of oxygen down its gradient; oxygen present in the environment is greater compared to oxygen in tissues and vice versa for carbon dioxide. After the oxygen is inhaled, the oxygen binds to hemoglobin and then travels via the bloodstream into the alveolar capillaries in the lungs. The oxygen rich blood goes into the right side of the heart and the left side pumps it to the rest of the body while exhibiting a greater oxygen partial pressure at this point than the atmosphere. The exchanges of gases between the capillaries and the cells of the body occur by the diffusion of

All living things need to respire in order to survive, this is necessary for energy and this is called Gas exchange. This is the exchange of different gases oxygen (O₂) and carbon dioxide (CO₂). During respiration oxygen is diffused into the cells of the organism and carbon dioxide is the waste product. However there is a form of respiration called anaerobic respiration where the oxygen is not used but the waste product is still carbon dioxide. If respiration did not occur the blood would not be oxygenated therefore energy wouldn't be able to change the state of the cells to enable life processes.

Fish exchange gases between the blood and the environment using gills. Gills are thin filamentous, vascular structures located just behind the head. Fish obtain the oxygen they need from the water by means of gills. Gills are membranous structures supported by cartilaginous or bony struts. Gill surfaces are very large due to numerous folds, but the gill filaments are very thin and respiratory gases are exchanged between the blood and the water by diffusion the folds are kept supported and moist by the water that is continually pumped through the mouth and over the gills. Fish Facilitate gas exchange by ventilating the gill surfaces, either by using the gill cover (operculum) as a pump, drawing water past the gill filaments (e.g. bony

One of the systems necessary for a mammal’s survival, that is not as necessary for those organisms of a lesser complexity, is the Respiratory system. For example, a Flatworm, otherwise known as the Platyhelminthes,

For the highest quality efficiency of gas exchange, the alveoli has multiple adaptations for example:

As a result of respiration, gas exchange occurs when Oxygen enters cells and carbon dioxide waste is excreted. In photosynthesis, carbon dioxide is required to enter cells while oxygen is released. Essentially gas exchange is achieved by diffusion (no energy required), where particles naturally move from an area of high concentration to low concentration.

During external respiration, oxygen and carbon dioxide move from the blood in the capillaries into the alveoli by diffusion. In internal respiration, cells release carbon dioxide as a byproduct of metabolism. Oxygen arrives via the hemoglobin in red blood cells. These red blood cells then in turn, carry carbon dioxide out from the cells to the pulmonary capillaries in the lungs to be exhaled. Oxygen and carbon dioxide also use the process of diffusion to move in and out of the cells and tissues during internal respiration. The process of respiration and gas exchange continues with each breath taken. It happens continuously from birth to death. This process is vital to life and the function of all cells in the human