The role of procoagulant microparticles in haemostasis Essay

The role of procoagulant microparticles in haemostasis - Essay Example Procoagulant MPs mostly appear as a result of apoptosis and vascular cell activation. An increase in the level of monocyte, platelet, or endothelial-derived MPs circulating in the blood is associated with CVD risk factors and indicates poor clinical outcome. They indicate vascular cell damage and interfere with atherothrombosis by exerting effects on vascular and blood cells. Under disease conditions, cellular cross-talk is supported by circulating MPs support, which leads to vascular inflammation, leukocyte adhesion, endothelial dysfunction, and stimulation. Functional tissue factor and exposed membrane phosphatidyserine are procoagulant entities produced by circulating MPs. Platelet derived MPs (PMPs) contain anionic phospholipid PS, which makes them strongly procoagulant. The removal of MPs from the blood of normal human plasma prolongs the clotting time (Ahn, 2005). Platelet derived MPs support thrombin generation in plasma without platelets, which are important for blood clottin g. Platelets form an important substrate for coagulation and their membranes provide a surface for the formation of prothrombinase complex. This enzyme is utilized in the conversion of fibrinogen to fibrin which combines with other factors to form a stable clot (Lawrie et al, 2009). The availability of platelet MPs at the site of vessel injury contributes to the clotting process by providing a large surface membrane necessary for enzymatic process. The exposure of phosphotidyserine during thrombin generation increases enzymatic catalytic effect. The large surface formed by MPs is necessary for activating the coagulation cascade that forms the fibrin clot. Circulating MPs harbor cytoplasmic effectors or functional membrane that promotes prothrombotic responses (Ay et al, 2009). These MPs channel their procoagulant potential to the target in the presence of the appropriate counter ligands. They bind onto soluble immobilized fibrinogen forming aggregates that enhance the delivery of pr ocoagulant entities. In vitro, TF and TF-dependent procoagulant mechanism is facilitated by the interaction of monocytes and endothelial MPs. TF is a constituent protein in minute amounts that flips the endothelial procoagulant properties resulting in the initiation of a TF-driven clotting process. Blood-borne TF can be incorporated in the developing thrombus through a series of TF-dependent, CD15 and CD18, and interactions. Blood-borne TF is mainly harbored by PMPs and monocyte-derived MPs provide the enzyme after lipopolysaccharide stimulation. Polunuclear leukocytes and endothelial-derived MPs also produce blood-borne TF under drastic endothelial activation. These MPs provide the required amount of TF and circulate the enzyme, which is necessary for maintaining a hemostatic balance. MPs, selectins and TF merge into an important triad of thrombosis. The surfaces of platelet and endothelial cells contain an important adhesion molecule called P-selectin (Hugel et al, 2005). The mole cule is utilized during TF accumulation and leukocyte inclusion in the thrombus when an endothelial injury occurs. The accumulation of hematopeic cell-derived TF is similar to the MPs accumulation kinetics before leukocyte-thrombus interaction. A soluble P-selectin enhances the production of leukocyte-derived TF-MPs used to correct hemostasis. The plasma levels of microparticles increase with age, which indicates the contribution of P-selectin pathway. P-selectin pathway also favors the transfer of PF into monocyte derived

Sustainable Corporate Strategy Group ASS SECTION 4 ONLY Essay

Sustainable Corporate Strategy Group ASS SECTION 4 ONLY - Essay Example In order to do this the regulators can call for a meeting of the manufacturers and discuss the technical size of the environmental parameters that should govern the industry in years to come. -Then the regulators have to obtain consensus from the automakers on the technologies that would help achieve the above parameters. These essentially fall into two categories -one that make futuristic cars light weight and thus environment friendly and two that use ignition technology based on newly evolved engines that help reduce emissions degrading the environment. -Smart Car has been using plastic formulations to reduce the weight of the car. In fact, the use of plastics for automotive applications has risen from about 27 kg per vehicle in 1970 to more than 163 kg in 1999. According to some 1999 European research studies, using 100 kg of plastic material in modern cars replaces between 200 and 300 kg of other materials. This, in turn, reduces fuel consumption by 750 liters over the 150,000 kilometers life span of the average car.(Plastics,1999) Regulator has to make decisions on the incorporation of plastic materials in car designs. Fr this automakers common opinion needs to be obtained.

Comparison and Contrast between schools of thought

Comparison and Contrast between schools of thought As organizations grew and became more complex, there arouse a need for systematic understanding of how to manage the overall process of getting things done through other people. To define management in the words of Harold Koontz and Heinz Weihrich management is the process of designing and maintaining an environment in which individuals, working together in groups, efficiently accomplish selected aims. Management is not as rigid as science nor is it a form of art; it is an inexact science and an applied art. It is a goal oriented process that is pervasive and multi-dimensional. Management has a vast spectrum of theories .management is divided into two major divisions, the classical school of thoughts and the Neo classical school of thoughts. The classical school encompasses Scientific Management of Taylor, Administrative Management of Fayol, and Bureaucratic Organization of Weber. The Neo-Classical Theory includes the Human Relations Movement of Mayo along with Dickson and a few others. And the Behavioral Schools of Maslow, McGregor, and Herzberg etc. The aim of this essay is to bring out the differences and similarities between the theories of the Scientific School of thoughts and the Behavioral school of thoughts. The basis of contrast and comparison will be the worker and the views of these schools of thought on handling and controlling the workforce as well as the workplace and the different ways in which they get things done through people. Fredrick Winslow Taylor, a trained engineer known as the father of scientific management or Taylorism noticed the differences in the labor productivity which were driven by various causes such as talent, skills, intelligence or motive. He believed that there was only one best way of performing any task. Scientific management called for simplification but specialization of work tasks. Taylor held out that even the most basic, mindless task could be planned in such a way that would drastically increase productivity and that scientifically managing the workers was more effective than the initiative and incentive method of motivating workers. He carried out various studies such as the time study, motion study and studied the various movements of the workers and in order to reduce wastage. F.W.Taylor introduced the piece rate system, under which every worker was paid a fixed piece rate for each unit produced. Henri Fayol was French mining engineer and a management theorist who has incalculably contributed to the modern concepts of management. He proposed six primary functions and 14 principles of management; they were highly influential in the classical school of management and are prime examples of the tenets of the classical approach to management. But the primary functions as well as the 14 principles were more task oriented rather than people oriented. Max Weber was a German sociologist and political economist, who profoundly influenced social theory, social research, and the discipline of sociology itself. Bureaucracy arose by sub-dividing the functions that the owner-managers originally did themselves such as supervision, personnel selection, accounting and financial management, record keeping, job design, and planning. Elton Mayo was an Australian psychologist, sociologist and organization theorist, the founder of Human Relations Movement and is known for his research including the Hawthorne Studies. The Hawthorne Studies of the 1930s showed the importance of groups in affecting the behavior of individuals at work. This study enabled him to drive at conclusions about how a manager should behave. He carried out numerous experiments on how to increase and improve productivity. He found out that when workers work in informal groups their work satisfaction varied to large extent. The human relations movement deemed that humans are motivated by social needs and work well when they are put in a group or as a team that is socially bound; the primary concern of any organization must be the satisfaction of social needs, only when an individual is socially satisfied will he be able to work effectively hence organizations are regarded as the co-operative social systems in which informal groups have a substant ial effect on productivity. Abraham Maslow a professor of psychology at Brandeis University founded humanistic psychology and created Maslows hierarchy of needs. At the bottom of the pyramid is the Basic needs or Physiological needs, the next level is safety needs. The third level of need is the need of being loved. The fourth level is achieved only when individuals are happy with what they have accomplished and are comfortable with it known as the Esteem level. The top of the pyramid is the need for self actualization. Douglas McGregor was the creator and developer of Theory X and Theory Y that are known as the theories of human motivation. They describe two very different attitudes towards workforce motivation. McGregor felt that companies followed either one of these approaches. He also thought that the key to connecting self-actualization with work is determined by the managerial trust of subordinates. The similarity between scientific school and behavioral school was that they both wanted to increase productivity by increasing the efficiency of the workers. On the course of Taylors pragmatic studies, he came across concepts that were not in common use in those days. One of it was the rest intervals; workers were taught to take rest intervals quite often which as a result increased production ironically. One of the variables Mayo and his colleagues studied after conducting the Hawthorne studies were the impact of rest intervals. These rest intervals increased the productivity of the workers. One of the key principles introduced by Taylor was Co-operation, not Individualism, which emphasized on team work rather than individuals performing tasks all alone. After conducting the Hawthorne studies Mayo concluded that the individuals whom he studied worked better when they were put in a group hence, opted for team work. Behavioral school holds that there must be a fusion between human needs and organizational goals. Every worker must understand that when an organizational goal is achieved it leads to fulfillment of their personal needs. The same idea is reflected in one of the principles conferred by Fayol.The principle subordination of individual needs to general needs explains that efforts must be made to reconcile individual interests with common interests. Thought it explains that employees interest must not prevail over the organization as a whole. Both the school of thoughts concludes that peoples interest is secondary to organizational goals. One of the principles contributed by Henri Fayol is esprit de corps which means team work. The management should never use the policy of divide and rule rather it should use the concept team work which in return increases production and satisfaction of workers. In the 1930s,after conducting the Hawthorne studies, Mayo and his colleagues concluded that people worked in a more effective and efficient manner when put in groups together. Team work promotes co-operation between the workers and as a team together they could work for the accomplishment of organizational goals. The main criticism of scientific approach is that it avoids the human element in production and is devoid of human touch. It treats workers as machines, factors of production rather than human beings. On the contrary behavioral approach was more concerned about human behavior and stated performance itself was not a product of working conditions but a bundle of feelings, attitudes and sentiments. Special attention and opportunity to express their feelings causes them to work in a more effective manner. Scientific management is based on the assumption that humans are rational and are mainly motivated by money. They strongly believed that people were motivated by physical and economic needs and disregarded social needs. On the other hand behavioral school stood at people are motivated only by social needs and not by money. Behavioral school considers one as a manager if he has human skills. It overlooks the other factor that builds the managerial qualification in a person. Whereas, scientific school strongly believes that a manager should have the following qualities. They are physical health, mental ability, moral, general education, special knowledge and experience. Behavioral school opts for social environment in the workplace particularly informal work group, interpersonal and in-group relations between employees and managers influences the workers behavior and performance in a positive way. Scientific management suggested a superior-subordinate relationship i.e. a formal organization Taylors motive was to increase productivity; his perspective was egronomical but not psychological, however being in contrast with Taylor, Mayo did not exterminate the informal organization, instead he tried to create stability amid the official and informal organization. After studying the scientific school and behavioral school of thoughts, the theories contributed by Henri Fayol stands to be my favorite theories and principles. He analyzed managerial jobs in a series of functions which were to be performed by all managers in all organizations. The functions that constitute the managerial functions are: Planning, Organizing, Directing, Staffing and Controlling. In addition to the managerial functions, he introduced 14 general principles of management that helped the managers to effectively manage the work environment. All his principles are universally accepted. All organizations face the problem of making optimum utilization of scarce resources. Therefore, these functions and principles are applicable to all sorts of organizations. Fayol believed that on the job experience method of learning is not adequate. Therefore, he suggested formal management training. Though both the schools of thoughts had two different approaches their aim was to maximize production in a more efficient way. Both the schools undertook very different ways to accomplish their goals. Thus, it can be concluded that an organization can apply the theories that belong to one school or both in order to excel production through increased efficiency. Scientific management and human relations go hand in hand and one is not less superior to the other. dd u do yu online a/c test? http://profile.ak.fbcdn.net/hprofile-ak-snc4/hs455.snc4/49919_1661875195_6869938_q.jpg 6:44pm nope ! we all doin it in uni tomm ! http://profile.ak.fbcdn.net/hprofile-ak-snc4/hs223.ash2/48905_1196147190_1324038_q.jpg 6:44pm umm..ok http://profile.ak.fbcdn.net/hprofile-ak-snc4/hs455.snc4/49919_1661875195_6869938_q.jpg 6:45pm u ? http://profile.ak.fbcdn.net/hprofile-ak-snc4/hs223.ash2/48905_1196147190_1324038_q.jpg 6:45pm evn b4 i opned it stated dat d paoer cn b atempted onli once :(:( http://profile.ak.fbcdn.net/hprofile-ak-snc4/hs455.snc4/49919_1661875195_6869938_q.jpg 6:46pm wat ? dummy only u r for takn it serious :p:p so i ws rite :P:P http://profile.ak.fbcdn.net/hprofile-ak-snc4/hs223.ash2/48905_1196147190_1324038_q.jpg 6:50pm :(:( http://profile.ak.fbcdn.net/hprofile-ak-snc4/hs455.snc4/49919_1661875195_6869938_q.jpg 6:51pm awwwwhhh .. dont be sad :P:P dummy :P:P ur a cute dummy ;);) :D:D hwz dat :P:P ? http://profile.ak.fbcdn.net/hprofile-ak-snc4/hs223.ash2/48905_1196147190_1324038_q.jpg 6:51pm shaap! dummy only u r for takn it serious :p:p so i ws rite :P:P http://profile.ak.fbcdn.net/hprofile-ak-snc4/hs223.ash2/48905_1196147190_1324038_q.jpg 6:50pm :(:( http://profile.ak.fbcdn.net/hprofile-ak-snc4/hs455.snc4/49919_1661875195_6869938_q.jpg 6:51pm awwwwhhh .. dont be sad :P:P dummy :P:P ur a cute dummy ;);) :D:D hwz dat :P:P ? http://profile.ak.fbcdn.net/hprofile-ak-snc4/hs223.ash2/48905_1196147190_1324038_q.jpg 6:51pm shaap!

Pygmalion and Society at the Time Essay -- Papers

Pygmalion and Society at the Time In this essay I will be discussing Bernard Shaw's representation of Edwardian Society in 'Pygmalion'. Shaw was a member of the Fabian Society; a collection of middle class people who believed that capitalism had created an unjust and unfair society. They were concerned about the unreasonable and imbalanced class system of the time and wanted to 'reconstruct society', creating an equal and fair civilisation with no class divide, which was so blatantly obvious due to the ignorance between classes. The rich lived lifestyles of luxury; the men would earn livings through land and property they owned and through careers such as scientists, lawyers and accountants. In the summer, they enjoyed a whole season of entertainment at their London house for tea and dinner parties, dances and visits to the theatre. In winter, they had holidays abroad and spent weekends at each other's country houses. The men went shooting and hunting and the ladies entertained themselves horse riding. Meanwhile, the poor were struggling on the dirty streets earning a pittance for manual jobs in workhouses and places similar. Conditions for them were sometimes so bad that they were forced to live in ridiculously over-crowded houses with other poor families. They could not afford new clothes or even food at times. They could certainly not afford luxuries like the rich enjoyed. The setting of Eliza's home and Mrs. Higgins' home show the both the pitiable living condition of the poor and the far from modest living conditions of the wealthy. Eliza can only afford the basic needs; a place to sleep, one set of clothes and limited light... ...h man, 'I sold flowers not myself.' Eliza's ability to reprimand Higgins is a bit of a shame for Higgins, as he is being scolded by someone who he had always considered lower than him. This illustrates again the fact that money does not buy you respect or manners and does not make you a good person. Shaw wanted the middle classes to realise and consider the working class. He was convinced that the way to alleviate the problem of poverty in society was to provide equal opportunity for all. This message is depicted in Eliza's transformation. Shaw also attacks middle class values and brands them hypocrites. He suggests that exposure to working class values might do them some good and teach them a valuable lesson. It is an influential message from start to finish and will persuade many people to consider others more.

Legal Aspects

Talking about the legal aspects of healthcare administration means taking into consideration the law that governs all the transactions that are carried out within the medical field so as to protect both the medical practitioner and the patient, with a dominant motive of bringing about improved quality of life devoid of diseases. It is believed widely that knowledge and the strengthening of these legal aspects will also bring ameliorations in the field of medicine and to this end, efforts are being made to make this set of information on the legal aspects as accessible as possible by feeding them into both the electronic media such as computers, televisions, and radios among others, and print media comprising the newspapers, journals, magazines, and periodicals among others. The ninth edition of the legal aspects of health tried to fulfill this purpose by taking a historical approach to the legal aspects of health care so as to showcase the accruals that have been made through these undertakings plainly when addressing their counterparts who are the pharmacists, physicians, physical therapists, assistant physicians, imaging technicians and respiratory therapists among others. Apart from the eighth edition chapter which revised the important issues of patient safety and sought to provide self assessment in evaluating the prospects of healthcare organizations, the World Wide Search chapter sought to inculcate global awareness in health and law –related spheres. This culminated in the ‘’last chapter journey to excellence’’ which after a decade of survey introduced an exotic approach into bolstering these laws to better the medical field by bringing healthcare institutions together (Pozgar & Santucci, 2006). On the other hand, the basic concepts of insurance portend the derivative, a table which shows the financial transactions that occur between two players; the insurer and the insured, in the field of insurance. The balance between what the two should pay each other being directly proportional to the magnitude of the danger involved for both parties. Although this concept is used as a formula to calculate the â€Å"expected payoff†, it is not yet adequate since it ignores the concept of inflation. According to Durbin, (1990) this problem can be solved by â€Å"discounting payoffs by a risk less return† and â€Å"using risk –adjusted probabilities that is â€Å"risk-neutral probabilities†. When calculating the payoffs. In a case whereby the insurer fails to dissolve risks through decentralization, the standoff can be resolved by â€Å"assuming the market price to be the value which will be used to infer the risk-neutral probabilities that determines these values† Durbin maintains that workers compensation insurance differs from liability insurance since in the former it is mandatory for employers to subscribe for their employees with the major cost component of workers compensation being loss of wages. This also covers occupational injuries and diseases picked at work-the employer assumes responsibility regardless of whose fault it was. It covers against dangers ranging from injuries, diseases, rehabilitation of the employee, loss of salary, medical treatment, to death. Conversely, liability insurance is a coverage that protects against claims against the insurance holder of property damage, personal injury, and negligence. The complainants could be the employees, the repair people, delivery people who may come into contact with the business property. There are two types of liability insurance: liabilities to non-members which covers mostly under a Comprehensive General Liability (CGL) terms and to members of the firm comprising employees and partners. The CGL normally covers payments resulting from accidents, immediate medical expense as a result of the above, the attorney fee and investigation expenses and the cost of court bonds. The difference between claims made and occurrence coverage is that the latter caters for claims made and reported to the insurer while the contract remains in force. During the primordial years when the policy is being renewed, the premium increases to take into account the potentiality of claims being reported from both current and previous policy periods. The former, normally regarded as the traditional form of coverage on the other hand is used to provide professional liability insurance. It caters for injury or damage incurred during the policy period regardless of when the claims are reported. Occurrence coverage also provides long term protection for any covered claims that may arise at any time in future (Robinson & Scherlen, 2007). Reference. Durbin, D. & Borba, P. (1993).Workers compensation. United States: Kluwer Academic. Durbin, T.B. & Durbin, T.B. Jr. (1990).Group insurance: basic concepts and alternatives. United States: American College Insurance Group Pozgar, G & Santucci, N. (2006).Legal aspects of healthcare and administration. United States: James &Bartlett Publishers. Robinson, M. & Scherlen R. (2007). Drug control. United States of America (USA): State University of New York Press.   

Water

Water is an essential ingredient for the existence of life as we know it. Biochemical processes occur in aqueous environments, many of which use water. Water also plays a significant role in the process of photosynthesis ( 6 CO2 + 6H2O + 672kcal -> C6H12O6 + 6O2 ). Photosynthesis is the most basic and significant chemical reaction on earth, providing the primary nutrients, directly or indirectly, for all living organisms and is the primary source of atmospheric oxygen. Without water and its unique and unusual properties, life as we know it on earth would not exist. Water is the only substance naturally present on the earth that exists in three distinct states -solid, liquid, and gas. Many of the unique properties in the take for granted include the three physical phases, transparency, universal solvents, density behavior and temperature, high specific heat, high heat of vaporization, viscosity, surface tension and low compressibility. To understand why these properties exist in water and why they are essential to life on earth it is important to look at the shape and bonding patterns of the molecule because the uniqueness of water is a direct result of its shape and bonding patterns. The shape of the water molecule In the water molecule the oxygen atom is the central atom. It has four pairs of valence electrons surrounding it. Two of these pairs are shared which form the shared pairs form covalent bonds with the hydrogen atoms. The remaining two pairs are unshared and have a greater repulsive effect than the shared pairs. The combined repulsive effect of the two unshared electron pairs produces an H-O-H bond angle that is smaller than the H-C-H bond angle (109. 47 degrees) in methane or the H-N-H bond angle (107 degrees) in ammonia. Actual measurement of the bond angle in water is 104. . If the two hydrogen nuclei were as far apart as possible the angle would be 109. 47. The unique bond angle in water is only 104. 5 degrees. The resulting shape of the molecule is referred to as â€Å"bent† or â€Å"angular†. Traditionally the VESPR model theory is used to predict molecular shape. See appendix A. Chemical bonding To understand the unusual properties of water as well as what causes them we need to have a basic understanding of the chemical bonding and the structure of the water molecule. The shape of the water molecule is determined in part by the chemical bonding that occurs. For a brief review of chemical bonding see appendix B. The water molecule consists of the elements hydrogen and oxygen. The chemical bonds in the water molecule are covalent bonds since the hydrogen atoms combine with the oxygen atoms in shared electron pairs. The oxygen atoms exerts a relatively strong pull on the shared electron pairs which causes the hydrogen atom to become electropositive regions and the oxygen atoms to become an electronegative region. The water molecule is considered a polar molecule because the positive and negative regions are not evenly distributed around a center point. The water molecule due to its polar nature is electrostatically attracted to other water molecules as well as other ions in solution. The attraction of the electropositive hydrogen atom to the electronegative oxygen atom of an adjacent water molecule is the bridging phenomenon known as hydrogen bonding and is only about 10 percent the strengths of a covalent bond. This special bond is responsible for most of the unusual properties of water: high freezing and boiling points, high heat capacity, high heat’s of fusion and evaporation, solvency, and high surface tension. Let us look more closely at the bonding patterns of water. Polar Covalent Bond When oxygen and hydrogen atoms are brought together the difference in their electronegativities is not sufficient to yield ions. Instead they must share a pair of electrons between them forming a covalent bond. Some sharing is more equal than others and oxygen’s greater electronegativity draws the electron pairs closer to its nucleus and further away from the hydrogen’s nuclei. This results in a concentration of negative charges nearer the oxygen atom and thus further from the positively charges protons that make the nuclei of the hydrogen atoms. The bond formed is intermediate between a fully ionic bond and a purely covalent bond. There is a separation of charges but not complete as in the formation of ions. The partial charge that is produced is symbolized by d. In Water, one side of the molecule, where the hydrogen atoms are, will be partially positively charged. The other side with the unshared pairs of electrons will be negatively charged. As a whole the molecule is polar. So it can be said that the water molecule has a polar covalent bond. The polarity of the water molecule makes mutual attraction between water molecules possible. The Hydrogen Bond Each molecule has a d- and d+ region. The attraction occurs between the d- and d+ regions (remember unlike charges attract). This means that each water molecule attracts four other water molecules to it. The hydrogen atom is attracted to the oxygen atom of the adjacent water molecule. Each oxygen atom can associate with two hydrogen atoms of other nearby water molecule through its unshared pair of electrons. The force of attraction between these polar molecules is not as strong as a covalent or ionic bond but strong enough to be significant. It is important enough to be called the HYDROGEN BOND. It is the hydrogen bonding that occurs between water molecules that accounts for many of the remarkable and vital properties of water that make the presence of water synonymous with life itself. Firstly, the ability of water to remain liquid over a large portion of the range of temperatures found on earth is one such vital property. Other molecules, as small as water (eg CO2), change from liquid to gas at temperatures far below that of water. It is also the Hydrogen bond which is responsible for the large amount of heat energy needed to convert water from liquid to gas. Water is therefore a great stabilizer of temperature which is essential to the survival of life on this planet. It accounts for more moderate temperatures near large bodies of water. This property is also exploited by many living organisms. Sweat, and its evaporation is a vital cooling process for biological mammals and depend greatly on the large amount of heat energy required to break the hydrogen bonds between water molecules. Hydrogen bonding maintains the integrity of the water molecule during chemical reactions. Other compounds undergo chemical changes (ionization), where as water will maintain its chemical integrity. As a result water is a poor conductor of electrical current. Hydrogen bonding is the reason for the lower density of ice relative to water. In conclusion, three main unique features which are the consequences of hydrogen bonding in water are: melting point, surface tension, density. These and other unique properties of water are responsible for the important role that water plays in life. Water’s Important Role Water is the single most abundant molecule in living things. It provides the medium in which most biochemical interactions occur. Some biochemical reactions water is involved in are: cellular respiration, digestion, and photosynthesis. Water is the home for many animals, plants and micro-organisms. Water is involved in the cycling of all other material by living things both on a local and global scale. Water has a number of unique and unusual properties that are responsible for its important roles it plays in the biosphere. BOILING AND MELTING POINTS. Water has unusually high boiling and freezing points compared to other compounds with similar molecular structure. A comparison of boiling and freezing points can be seen in the following chart. Notice only water has a boiling and melting point that exists within the range of life. The boiling point of water is a unique 100oC results is and the freezing point is a remarkable 0oC due to the fact of the polar nature of the water molecule and hydrogen bonding. Two important, but not unique, properties of water for life are that water is liquid at normal temperatures over much of the earth and that water is transparent. If water were not liquid, nutrients could not flow from soil to the roots of plants, blood could not circulate, and bodies of organisms would be so rigid that they could not move. If water were not transparent, light could not penetrate through cellular protoplasm into chloroplasts to drive photosynthesis in plants, you would be blind because light could not penetrate through the vitreous humor to the retina of your eyes, and light could not penetrate into lakes to allow growth of phytoplankton. Clearly life cannot exist without the amazing properties of water. SOLVENT CAPABILITY. A solvent is a substance capable of dissolving another substance (solute) to form a homogeneous mixture (solution) at a molecular level. The polar nature of water makes it an excellent solvent especially with other polar compounds such as salts, alcohols, carboxylic compounds and many more. As a solvent water is unsurpassed in it’s ability to dissolve a wide range of inorganic and organic substances. More substances dissolve in water than any other known substance. The versitility of water as a solvent allows it to serve as the medium of transport for so many materials. This is true both for individual organism and for the biosphere as a whole. The essential transport systems including blood, lymph, and urine are all water based. Without water’s solvent capabilities to make three systems work, life could not exist. A LESS DENSE SOLID FORM. Water exists in liquid form over a wide range of temperatures outside of which life processess are slowed down or halted completely. Between 4?c and the freezing point at 0?c, an amazing thing happens that occurs with very few substances, Water gradually expands becoming less dense. Water is the only substance where the liquid state is heavier than the solid state. All other substances the solid form is denser than the liquid form. Since the density of ice is less than that of liquid Walter, ice floats on water. It is very significant that ice expands and floats on water because if lakes and streams froze from the bottom to the top, aquatic life would not even exist, and climate and weather patterns would be altered drastically. This is an important quality of water because as ice forms it floats on top of the water. It acts to provide a thermal blanket for the rest of the water beneath and all its many life forms. This is important because if water behaved like all other substances, water bodies would freeze from the bottom up and in most cases would never thaw completely during summer. This would have a dramatic cooling effect globally and would impact all life on earth. LARGE HEAT CAPACITY. The remarkable property of water is it’s extremely high capacity to absorb heat without a significant increase in temperature. We see examples of this all the time. For example, under the summer sun at the beach, sand will increase in temperature to the point where it is too hot to walk on, whereas the water temperature is still cool, even though both are heated by the same amount of solar heat energy. Water has the largest heat capacity of any common substance. This means that water takes more heat energy to raise the temperature of water a given number of degrees than for any other material. In cooling water gives up more heat than any other material. This property is important globally and individually. Individually, the high heat capacity buffers organisms from sudden extreme shifts in temperature which would be harmful to it. Globally, the oceans moderate seasonal temperature fluctuations. That is why coastal areas are cooler than inland areas at the same latitude. These differences influence the weather globally. And without weather changes life would be very unbearable. The absorption of huge amounts of solar heat energy by water during the day and the slow release of heat energy during the night is responsible for the moderate climate in the coastal areas. A wider range of temperatures typically exist inland away from bodies of water. If not for the vast oceans on earth tempering the climate life would not exist. This property combines with the MPIBP property to create the water cycle which supports life on earth. HIGH HEAT OF VAPORIZATION. Water has an extraordinarily high heat of vaporization. On average it takes 580 calories to convert one gram of water into water vapour. A value that is higher than any other common substance. This property is of important significance to animals in regulating body temperature because of the large amount of body heat that is required to evaporate water (sweat). Without this property of water, organisms would overheat and die and the climate would be thrown into chaos. SURFACE TENSION. Water has the highest surface tension of any other liquid except Mercury. Surface tension is the attractive force exerted by the molecules below the surface on those at the liquid-air interface. The liquid is restrained from flowing by this inward force. The exceptionally high surface tension of water is due to the hydrogen bonding of water. This is demonstrated when you see an insect being able to support itself on the surface layer of water. The surface tension also leads to a higher viscosity as it doesn’t flow as easily. This is known as the clumping effect like the high melting point and boiling point the clumping effect occurs in liquid, that have hydrogen bonding. Conclusion All of these unusual properties stem from the unusual structure and bonding patterns of the water molecule. The molecule is strongly polar because of its uneven distribution of electrons. This allows water to interact easily with other polar substances which accounts for the great solvent power of water. The electronegativity difference between the oxygen and hydrogen atoms in water molecules is responsible for the establishing of hydrogen bonds between molecules. It is the mutual attraction of water molecules that accounts for the ability of water to remain liquid over a broad range of temperature (0oC-100oC) and also for its high heat of vaporization and high heat capacity. Water could not have all these special characteristics/properties without its unique shape and bonding patterns, life could not exist if not for these special properties of water, espacally the hydrogen bond. You can order a custom essay, term paper, research paper, thesis or dissertation on water from our professional custom writing service which provides high-quality custom written papers on any topic.