Elements in the Human Body and What They Do

Elements in the Human Body and What They Do There are several ways to consider the composition of the human body, including the elements, type of molecule, or type of cells.  Most of the human body is made up of water, H2O, with cells consisting of 65-90% water by weight. Therefore, it isnt surprising that most of a human bodys mass is oxygen. Carbon, the basic unit for organic molecules, comes in second. 99% of the mass of the human body is made up of just six elements: oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus. Oxygen (O) - 65% - Oxygen together with hydrogen form water, which is the primary solvent found in the body and is used to regulate temperature and osmotic pressure. Oxygen is found in many key organic compounds.Carbon (C) - 18% - Carbon has four bonding sites for other atoms, which makes it the key atom for organic chemistry. Carbon chains are used to build carbohydrates, fats, nucleic acids, and proteins. Breaking bonds with carbon is an energy source.Hydrogen (H) - 10% - Hydrogen is found in water and in all organic molecules.Nitrogen (N) - 3% - Nitrogen is found in proteins and in the nucleic acids that make up the genetic code.Calcium (Ca) - 1.5% - Calcium is the most abundant mineral in the body. Its used as a structural material in bones, but it is essential for protein regulation and muscle contraction.Phosphorus (P) - 1.0% - Phosphorus is found in the molecule ATP, which is the primary energy carrier in cells. Its also found in bone.Potassium (K) - 0.35% - Potassium is an im portant electrolyte. Its used to transmit nerve impulses and heartbeat regulation. Sulfur (S) - 0.25% - Two amino acids include sulfur. The bonds sulfur forms help give proteins the shape they need to perform their functions.Sodium (Na) - 0.15% - Sodium is an important electrolyte. Like potassium, it is used for nerve signaling. Sodium is one of the electrolytes that helps regulate the amount of water in the body.Chlorine (Cl) - 0.15% -  Chlorine is an important negatively-charged ion (anion) used to maintain fluid balance.Magnesium (Mg) - 0.05% - Magnesium is involved in over 300 metabolic reactions. Its used to build the structure of muscles and bones and is an important cofactor in enzymatic reactions.Iron (Fe) - 0.006% - Iron is found in hemoglobin, the molecule responsible for oxygen transport in red blood cells.Copper (Cu), Zinc (Zn), Selenium (Se), Molybdenum (Mo), Fluorine (F), Iodine (I), Manganese (Mn), Cobalt (Co) - total less than 0.70%Lithium (Li), Strontium (Sr), Aluminum (Al), Silicon (Si), Lead (Pb), Vanadium (V), Arsenic (As), Bromine (Br) - pres ent in trace amounts Many other elements may be found in extremely small quantities. For example, the human body often contains trace amounts of thorium, uranium, samarium, tungsten, beryllium, and radium. Trace elements considered essential in humans include zinc, iodine, possibly silicon, probably boron, selenium, probably nickel, chromium, manganese, lithium, possibly arsenic, molybdenum, cobalt, and possibly vanadium. Not all of the elements found within the body are essential for life. Some are considered contaminants that appear to do no harm, but serve no known function. Examples include cesium and titanium. Others are actively toxic, including mercury, cadmium, and the radioactive elements. Arsenic is considered to be toxic to humans, but serves a function in other mammals (goats, rats, hamsters) in trace amounts. Aluminum is interesting because it is the third most common element in the Earths crust, yet serves no known function in living cells. While fluorine is used by plants to produce protective toxins, it serves no essential biological role in human beings. You may also wish to view the  elemental composition of an average human body  by mass. Sources Chang, Raymond (2007). Chemistry, 9th Edition. McGraw-Hill. ISBN 0-07-110595-6.Emsley, John (2011). Natures Building Blocks: An A-Z Guide to the Elements. OUP Oxford. p. 83. ISBN 978-0-19-960563-7.Frausto Da Silva, J. J. R; Williams, R. J. P (2001-08-16). The Biological Chemistry of the Elements: The Inorganic Chemistry of Life. ISBN 9780198508489.H. A., V. W. Rodwell; P. A. Mayes, Review of Physiological Chemistry, 16th ed., Lange Medical Publications, Los Altos, California 1977.Zumdahl, Steven S. and Susan A. (2000). Chemistry, 5th Edition. Houghton Mifflin Company. p. 894. ISBN 0-395-98581-1. Elements in the Human Body and What They Do

English Legal System, Coursework Essay Example | Topics and Well Written Essays - 1750 words

English Legal System, Coursework - Essay Example The main feature of the English legal system is that it is living and constantly evolving to work in the future as well as it did in the past1. Thus the single most unique feature of the English legal system is its inheritance from common law2. Most of the characteristics commonly linked to English law and its management of righteousness are traceable to the early on growth in Western Europe of the civil and common law customs. According to Goodman (1995), "several characteristic consequences flow from the fact that law did not emanate from one centralised authority such as papacy, king or parliament. The odd growth of the common law in England developed it appears from a coincidence resemblance of the implementation after the Norman take-over by consecutive monarchs of native customs as the foundation for the governance of justice. Conflict assessment, chiefly concerning land title, was a key function for justice. Judges were nominated by the king to tour the country and decide controversies, aided by a local adjudicator included by the Normans into operational royal courts. The trial accepted a key role in the settlement of disputes. Wilson (1995) states that "Everyone takes for granted the fact that law and legal systems differ in different countries. But it is also true of legal scholarship. One reason for this is the different responsibilities legal scholars have in different countries for the maintenance and development of the local law...One result is that legal scholars in different countries may have different agendas and this may affect the subject matter, scope and even the form and style of the local legal scholarship." (Source: http://www.chriswallis.com/uni/cnlaw231l01.pdf accessed on November 5 2009). To bring about a faith to the law the courts followed the principle of stare Decisis.3 This is referred to as the doctrine of precedent. The courts are divided into two (IALS Conference, Learning from Each Other: Enriching the Law School Curriculum in an Interrelated World). They are: i. Superior courts; ii. Inferior courts. The House of Lords is the superior court but it is a UK court since it practices appellate authority for all the three legal systems.4 The Superior Courts are known as the Supreme Court from November 2009. The Supreme Court consists of the High Court, the Crown Court and the Court of Appeal (IALS Conference, Learning from Each Other: Enriching the Law School Curriculum in an Interrelated World). The doctrine of precedent's role in the English legal system is very important since common law is a vital basis of law in the English legal system. This is opposite to the European legal system as it is founded on legal examples and possibilities. A lot of stages of study have to be conducted under a common law jurisdiction so that it can be understood as to what the law is. The facts of the law have to be understood first and then any relevant statutes or legal cases have to be located. Finally the principles 3. Meaning "let the decision stand". 4. However the jurisdiction is not universal. For example, whilst there is a right of appeal to the House of Lords against civil actions in Scotland no such right exists for criminal matters. and the decisions used in the case are used for the future