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Recommended: Homeostasis zoology
Many organisms are presented in various environments all over the world. Some of them see extreme environments as their cradles of life: volcano hot spring, extremely salty lake water or even deep ocean where there lacks light or oxygen. But these organisms have their very own mechanisms; have already embedded in their genetic materials. But there are also organisms showed adaptations to some experimental environments in researches, which proves that these adaptive mechanism are not only genetically determined, but also can be triggered when these special functions are needed as one fundamental strategy of surviving in the nature. But not only the organisms live in extreme conditions have the ability to find strategies to survive. These adaptations can be explored in our very own body.
The organisms will be discussed in the following paragraph will be mostly single cells or even organic molecules. Since the following aspects of discussions will be focusing about the cellular functions or strategies of regulations of the homeostasis.
Some organisms like the extreme thermophiles (Campbell, N. A., et. Al, 2009), can survive in inhabitable environment, which is the acrhaea in the genus Sulfolobus. These archaea can survive and function normally in the sulphur-rich volcanic springs, where could be hot as 90 degree Celsius, lack of food and contain a high dosage of sulphur. Normally, most organisms would not be able to survive as the protein that constructs our body tissue will change their shape under the heat (above 90 degree Celsius), and these changes of the shape can lead to the dysfunction and denature of the enzymes. (But these Sulfolobus have their special genetic information sequencing so their ribosome can induce the...
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... (see Endothelium)
3. Duncan, R. F. and J. W. B. Hershey. Protein synthesis and protein phosphorylation during heat stress, recovery, and adaptation. J. CeZZ Biol. 109: 1467-1481, 1989.
4. Huckle, W. R., "Cellular modes of adaptation to environmental changes", Proc. SPIE 4512, 100 (2001); doi:10.1117/12.446756
5. Lu, D., Maulik, N., Moraru, I. I., Kreutser, D. L.& Das, D. K., Molecular adaptation of vascular endothelial cells to oxidative stress, Am J Physiol Cell Physiol March 1993 vol. 264 no. 3 C715-C722 ( fig1&2)
6. Wiegant, F. A. C., P. M. P. van Bergen en Henegouwen, G. van Dongen, and W. A. M. Linnemans. Stress-induced thermotolerance of the cytoskeleton. Cancer Res. 47: 1674-1680,1987.
7. Zhu, H. & Bunn, H. F., "Oxygen sensing and signaling: impact on the regulation of physiologically important genes," Respir. Physiol. 115, pp. 239-247, 1999.
The gaseous free radical nitric oxide is an abundant intracellular messenger molecule that plays a central role in maintenance of health, and is heavily involved in signal transduction in various cells of the body [1]. This molecule acts as a mediator in the regulation of cardiac function as well as having an important role in regulating contractility of the heart and maintenance of vascular tone in the cardiovascular system. As one of the most significant individuals in our discovery of nitric oxide, Dr. Robert Furchgott pioneered our understanding of this molecule through his experiments on the vasorelaxant properties of acetylcholine and the subsequent proposal of the presence of the endothelium derived relaxing factor, which was later identified to be nitric oxide [7]. Given the observation that cardiovascular disorders are the number one cause of death in many nations around the world, research into the vasorelaxant properties seems particularly relevant in order to help combat rising rates of vascular hypertension and high blood pressure. In this paper, the properties of nitric oxide are discussed largely with respect to the cardiovascular system. This paper focuses on the synthesis and characteristics of nitric oxide, the mechanisms of action by which nitric oxide works and the regulation of nitric oxide in the body, and finally a short summary of Robert Furchgott’s contributions to the discovery of nitric oxide and its properties.
Miller, K. R., & Levine, J. S. (2010). Miller & Levine biology. Boston, Mass.: Pearson.
Thewessen, J. G. M., Williams, E. M., Roe, L. J. & Hussain, S. T. Nature 413, 277-281.
The problem is that it is difficult to locate the genes that stimulate adaptation for three reasons:
Eukaryotic cells, whether from animals, plants, protists, or fungi, are the most structurally advanced of the major cell types. Eukaryote are single-celled or multicellular organism whose cells contain nucleus and any other structures (organelles) enclosed within the membrane that perform specific functions. The surface of the cell is covered with a thin film or plasma membrane, which is the boundary that separates the living cell from its nonliving surroundings. Plasma membranes are composed mostly of proteins and lipids (Simon, 02/2012, p. 59-60).
Oxidative stress is critical as it is extensively related to human diseases, such as rheumatoid arthritis, Alzheimer’s, Parkinson’s, diabetes, cataract, aging and cancer (Zhao and Zha...
All living things are made up of enzymes and proteins that break down when the organism is exposed to extreme life threatening conditions (visualinsight.net). Extremophiles are believed to have adapted to these extreme conditions because of “heat stress proteins.” Scientists have discovered special molecules, also known as “molecular chaperons,” that are produced when the organism is exposed to deadly conditions. These molecules are activated and will repair the proteins damaged by stressful encounters in the same way a human will develop a fever to fight off infection. The fever activates these “savior proteins” and healing
Based on experimental evidence from the Astyanax mexicanus investigation, it can be argued that eye regeneration in the dark cave environment is due to adaptive evolution. Experiments that have been carried out on Astyanax cavefish do not seem to favor the neutral mutation theory. The results from these experiments have shown that several eye genes are pleiotropic and regulatory since they have many functions in development in addition to their eye forming roles. This means that the genes do not experience the neutral decay process. Even critical eye structural genes such as retinal opsin, which functions at the base of gene cascades, are still expressed during the eye development of cavefish. This is why the adaptation hypothesis based on pleiotropy is the most credible explanation behind the loss of eyes in cave-adapted animals.
Since cell membranes make up an important part of life it’s important to know how certain factors such as physical stress particularly the temperature effect the membrane and the vulnerability of these membranes. In both extremes of temperature, the membrane is susceptible to the degradation of the membrane due to the expansion of water when freezing or lack of diffusion when there is too much heat.
Colgan, Wes III, Ramsey, Linda, White, James D., and Spaulding, Jim. Explorations in Biology. 6th ed. Boston: Pearson, 2010. 33-36. Print.
According to Darwin and his theory on evolution, organisms are presented with nature’s challenge of environmental change. Those that possess the characteristics of adapting to such challenges are successful in leaving their genes behind and ensuring that their lineage will continue. It is natural selection, where nature can perform tiny to mass sporadic experiments on its organisms, and the results can be interesting from extinction to significant changes within a species.
In an environment that changes often or a species moves to a different environment a genotype has the ability to produce various phenotypes to sustain the environment. The ability for the genotype to process different phenotypes based on the pressures in the environment is called phenotypic plasticity. Phenotypic can be rapid or gradual depending on the environment and the features need for adaptation. An adaptive phenotype will be able to change morphology, behavior, and development alterations (Futuyma, 2013). Developmental may not be able to be reversed, but the changes can happen rapidly. An adaptive phenotype will be able to alter its phenotype when the environment changes, resulting in different phenotypes to adapt. Adaptive will increase the fitness of a species, because they will be able to adapt quickly to different environments increasing their chances of survival. A non-adaptive phenotype will decrease the fitness of a species. This phenotype may change the species to go against or resist the changes in the environment or not adapt at all. If the species does not change...
“Homeostasis” was first described by Claude Bernard, a French physiologist in 1865. It can be defined as the ability of an organism or cell to maintain its internal environment by the system of feedback controls. Homeostasis preserves a stable internal environment as surroundings change inside and outside the cell and is a significant characteristic of living being. It also plays a key role in the survival and proper functioning of the human body. The maintenance of systems within a cell is called ‘homeostatic regulation’. Homeostasis is controlled by three different mechanisms: Osmoregulation, Thermoregulation and chemical regulation. These different mechanisms are carried out by different systems of the body such as endocrine system, nervous system, exocrine system, respiratory system, reproductive system.
Campbell, N. A. & J. B. Reece, 8th eds. (2008). Biology. San Francisco: Pearson Benjamin Cummings.
Milk production, milk fat, protein content and the progression of breeding are also affected, especially in dairy cows. When heat stress occurs, dairy cows tend to reduce the intake of dry matter in order to control their heat production from increasing through the process of metabolism and digestion (Donnelly, 2012).... ... middle of paper ... ... Retrieved from: http://www.extension.umn.edu/agriculture/dairy/facilities/economic-impacts-of-heat-stress IFAD.