What Is a Peptide Definition and Examples

A peptide is a molecule consisting of two or more amino acids linked together by peptide bonds. The general structure of an amino acid is: R-CH(NH2)COOH. Each amino acid is a monomer that forms a peptide polymer chain with other amino acids when the carboxyl group (-COOH) of one amino acid reacts with the amino group (-NH2) of another amino acid, forming a covalent bond between the amino acid residues and releasing a molecule of water. Key Takeaways: Peptides A peptide is a polymer formed by linking amino acid subunits.A peptide molecule may be biologically active on its own or it may act as a subunit for a larger molecule.Proteins are essentially very large peptides, often consisting of multiple peptide subunits.Peptides are important in biology, chemistry, and medicine because they are building blocks of hormones, toxins, proteins, enzymes, cells, and body tissues. Functions Peptides are biologically and medically important molecules. They naturally occur within organisms, plus lab-synthesized compounds are active when introduced into a body. Peptides act as structural components of cells and tissues, hormones, toxins, antibiotics, and enzymes. Examples of peptides include the hormone oxytocin, glutathione (stimulates tissue growth), melittin (honey bee venom), the pancreatic hormone insulin, and glucagon (a hyperglycemic factor). Synthesis Ribosomes in cells construct many peptides, as RNA is translated into an amino acid sequence and the residues are linked together. There are also nonribosomal peptides, which are constructed by enzymes rather than ribosomes. In either case, once amino acids have been linked, they undergo posttranslational modifications. These may include hydroxylation, sulfonation, glycosylation, and phosphorylation. While most peptides are linear molecules, some form rings or lariat structures. Less often, L-amino acids undergo racemization to form D-amino acids within peptides. Peptide Versus Protein The terms peptide and protein are commonly confused. Not all peptides form proteins, but all proteins consist of peptides. Proteins are large peptides (polypeptides) containing 50 or more amino acids or molecules that consist of multiple peptide subunits. Also, proteins typically display more complex structure than simpler peptides. Classes of Peptides Peptides may be classified either by their function or by their source. The Handbook of Biologically Active Peptides lists groups of peptides, including: Antibiotic peptidesBacterial peptidesBrain peptidesCancer and anticancer peptidesCardiovascular peptidesEndocrine peptidesFungal peptidesGastrointestinal peptidesInvertebrate peptidesOpiate peptidesPlant peptidesRenal peptidesRespiratory peptidesVaccine peptidesVenom peptides Naming Peptides This is an example of a tetrapeptide, with the N-terminus in green and the C-terminus in blue. JÃ ¼ Peptides are named according to how many amino acid residues they contain or according to their function: Monopeptide: consists of one amino acidDipeptide: consists of two amino acidsTripeptide: has three amino acidsTetrapeptide: has four amino acidsPentapeptide: has five amino acidsHexapeptide: has six amino acidsHeptapeptide: has seven amino acidsOctapeptide: has eight amino acidsNonapeptide: has nine amino acidsDecapeptide: has ten amino acidsOligopeptide: consists of between two and twenty amino acidsPolypeptide: linear chain of many amino acids linked by amide or peptide bondsProtein: either consists of more than 50 amino acids or multiple polypeptidesLipopeptide: consists of a peptide bonded to a lipidNeuropeptide: any peptide active in neural tissuePeptidergic agent: chemical that modulates the functioning of peptidesProteose: peptides produced by the hydrolysis of proteins Peptides in Sports Two types of peptides are classified as Schedule 2 (S2) prohibited substances on the World Anti-Doping Agency (WADA) Prohibited List, United States Anti-Doping Agency (USADA) Prohibited List, and by the Australian Sports Anti-Doping Authority. Peptide hormones and secretagogue peptides are banned for use by professional athletes, whether or not they are in competition, because the chemicals act as performance enhancers. The banned peptides are growth hormones, those that increase blood oxygenation, ones that affect muscle growth and repair, and those that cause endocrine system organs (e.g., ovaries, testes, thyroid) to secrete hormones. The substances are banned not only because they can give athletes an unfair advantage over peers, but because their use can increase the risk of hypertension, water intoxication, heart and liver damage, and cancer. Sources Abba J. Kastin, ed. (2013). Handbook of Biologically Active Peptides (2nd ed.). ISBN 978-0-12-385095-9.Ardejani, Maziar S.; Orner, Brendan P. (2013-05-03). Obey the Peptide Assembly Rules. Science. 340 (6132): 561–562. doi:10.1126/science.1237708Finking R, Marahiel MA; Marahiel (2004). Biosynthesis of Nonribosomal Peptides. Annual Review of Microbiology. 58 (1): 453–88. doi:10.1146/annurev.micro.58.030603.123615IUPAC. Compendium of Chemical Terminology, 2nd ed. (the Gold Book). Compiled by A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford (1997). ISBN 0-9678550-9-8.

The Great Gatsby By F. Scott Fitzgerald - 992 Words

The Jazz Age was a period of great economic, social, and political change happening in the 1920’s. The Great Gatsby by F. Scott Fitzgerald, however, sees in this a time of boundaryless death, and urban decimation. The Great Gatsby is modeled towards the death of the American dream during the 1920’s. Based on the happening of the 1920’s, this model is certainly reasonable. F. Scott Fitzgerald and The Great Gatsby use the motifs of materialism, carelessness, and decay seen in the 1920’s in order to show a decimation of the American Dream, and the human race. Throughout The Great Gatsby it is very easy to recognize how the time period affected the author s point of view, one of the motifs that is affected by the time period is materialism. During the 1920’s the view of money shifted from a common commodity to a necessity that is only available to the gifted, or to criminals. A race for money caused people to move to cities, spend more time at their job s, and overall become less human (The Roaring Twenties). A materialist society quickly ensued, which F. Scott Fitzgerald points to in The Great Gatsby. â€Å"My house looks well, doesn’t it?† (89). Gatsby seeks the approval of Tom and Daisy for his over-emasculate house. He is actively attempting to buy his way into a social class and a way of life. Gatsby believes that money can buy him love in the form of Daisy, the same way that 1920’s city-workers believed that money could buy them happiness. George Wilson believes money canShow MoreRelatedThe Great Gatsby by F. Scott Fitzgerald1393 Words   |  6 PagesF. Scott Fitzgerald was the model of the American image in the nineteen twenties. He had wealth, fame, a beautiful wife, and an adorable daughter; all seemed perfect. Beneath the gilded faà §ade, however, was an author who struggled with domestic and physical difficulties that plagued his personal life and career throughout its short span. This author help ed to launch the theme that is so prevalent in his work; the human instinct to yearn for more, into the forefront of American literature, where itRead MoreThe Great Gatsby By F. Scott Fitzgerald1343 Words   |  6 PagesHonors English 10 Shugart 18 Decemeber 2014 The Great Gatsby F. Scott Fitzgerald s 1925 novel The Great Gatsby is a tragic love story, a mystery, and a social commentary on American life. The Great Gatsby is about the lives of four wealthy characters observed by the narrator, Nick Carroway. Throughout the novel a mysterious man named Jay Gatsby throws immaculate parties every Saturday night in hope to impress his lost lover, Daisy Buchanan. Gatsby lives in a mansion on West Egg across from DaisyRead MoreThe Great Gatsby By F. Scott Fitzgerald1155 Words   |  5 PagesThe Great Gatsby The Jazz Age was an era where everything and anything seemed possible. It started with the beginning of a new age with America coming out of World War I as the most powerful nation in the world (Novel reflections on, 2007). As a result, the nation soon faced a culture-shock of material prosperity during the 1920’s. Also known as the â€Å"roaring twenties†, it was a time where life consisted of prodigality and extravagant parties. Writing based on his personal experiences, author F. ScottRead MoreThe Great Gatsby By F. Scott Fitzgerald1166 Words   |  5 Pagesin the Haze F. Scott Fitzgerald lived in a time that was characterized by an unbelievable lack of substance. After the tragedy and horrors of WWI, people were focused on anything that they could that would distract from the emptiness that had swallowed them. Tangible greed tied with extreme materialism left many, by the end of this time period, disenchanted. The usage of the literary theories of both Biographical and Historical lenses provide a unique interpretation of the Great Gatsby centered aroundRead MoreThe Great Gatsby by F. Scott Fitzgerald845 Words   |  3 PagesIn F. Scott Fitzgerald’s novel, The Great Gatsby, colors represent a variety of symbols that relate back to the American Dream. The dream of being pure, innocent and perfect is frequently associated with the reality of corruption, violence, and affairs. Gatsby’s desire for achieving the American Dream is sought for through corruption (Schneider). The American Dream in the 1920s was perceived as a desire of w ealth and social standings. Social class is represented through the East Egg, the WestRead MoreThe Great Gatsby By F. Scott Fitzgerald Essay970 Words   |  4 Pagesrespecting and valuing Fitzgerald work in the twenty-first century? Fitzgerald had a hard time to profiting from his writing, but he was not successful after his first novel. There are three major point of this essay are: the background history of Fitzgerald life, the comparisons between Fitzgerald and the Gatsby from his number one book in America The Great Gatsby, and the Fitzgerald got influences of behind the writing and being a writer. From childhood to adulthood, Fitzgerald faced many good andRead MoreThe Great Gatsby By F. Scott Fitzgerald2099 Words   |  9 Pagesauthor to mirror his life in his book. In his previous novels F. Scott Fitzgerald drew from his life experiences. He said that his next novel, The Great Gatsby, would be different. He said, â€Å"In my new novel I’m thrown directly on purely creative work† (F. Scott Fitzgerald). He did not realize or did not want it to appear that he was taking his own story and intertwining it within his new novel. In The Great Gatsby, by F. Scott Fitzgerald, he imitates his lifestyle through the Buchanan family to demonstrateRead MoreThe Great Gatsby By F. Scott Fitzgerald1607 Words   |  7 Pages The Great Gatsby is an American novel written in 1925 by F. Scott Fitzgerald. One of the themes of the book is the American Dream. The American Dream is an idea in which Americans believe through hard work they can achieve success and prosperity in the free world. In F. Scott Fitzgerald s novel, The Great Gatsby, the American Dream leads to popularity, extreme jealousy and false happiness. Jay Gatsby’s recent fortune and wealthiness helped him earn a high social position and become one of the mostRead MoreThe Great Gatsby By F. Scott Fitzgerald1592 Words   |  7 PagesMcGowan English 11A, Period 4 9 January 2014 The Great Gatsby Individuals who approach life with an optimistic mindset generally have their goals established as their main priority. Driven by ambition, they are determined to fulfill their desires; without reluctance. These strong-minded individuals refuse to be influenced by negative reinforcements, and rely on hope in order to achieve their dreams. As a man of persistence, the wealthy Jay Gatsby continuously strives to reclaim the love of hisRead MoreThe Great Gatsby By F. Scott Fitzgerald1646 Words   |  7 PagesThe 1920s witnessed the death of the American Dream, a message immortalized in F. Scott Fitzgerald’s The Great Gatsby. Initially, the American Dream represented the outcome of American ideals, that everyone has the freedom and opportunity to achieve their dreams provided they perform honest hard work. During the 1920s, the United States experienced massive economic prosperity making the American Dream seem alive and strong. However, in Fitzgerald’s eyes, the new Am erican culture build around that

Assignment Blood Disorder Free Essays

Assignment: Blood Disorders There are many blood disorders and some we cause ourselves, some are genetic and are caused even before we are born. A person can be affected with blood disorder at any time in life, lifestyle, family history and some symptoms are always in which blood disorders are identified. Then we have our environmental issues also can cause blood disorders, it is very important to know what we are dealing with and how to prevent measures that will help us avoid any of the self made blood disorders. We will write a custom essay sample on Assignment: Blood Disorder or any similar topic only for you Order Now Some are being caused by bad nutritional habits, but we are very fortunate to be able to control some blood disorders; however there are those countries that have little available to overcome certain kinds of anemia. The blood disorders in the three case scenarios are all different, Iron deficiency anemia is a blood disorder that is affecting Amy who is a 4 year old Caucasian female, she has been complaining of being tired all the time she is a picky eater, because her mom cannot afford to feed a large family due to her being a single mom. The lack of iron deficiency or insufficient iron intake in the hemoglobin of the red blood cells can cause iron deficiency anemia. Amy needs a physical exam and needs blood work done to determine the cause of her anemia. Special blood tests are used to detect rare causes of anemia the blood test that Amy needs to get done are CBC (complete blood count) that determines the volume, size, number and hemoglobin content of her red blood cells. If the physician is still in doubt further testing may include checking the blood levels of iron and ferritin, a protein that binds iron in the blood, which may more accurately reflect the body’s iron level. Sometimes iron deficiency many not cause any symptoms, when iron deficiency has progressed to actual anemia, there can be fatigue, unusually pale skin, and a decreased ability to exercise. Since Amy does not eat a proper diet she really needs this blood test done and be seen by a pediatrician on regular basis. The recommended treatment for Amy is to improve her eating habits and to be monitored of her red blood cell count including her iron count. After being seen by a pediatrician she will be given a list of foods that she needs to include in her daily meals. Lean red meats, beans, egg yolk, whole grain products, nuts (making sure that Amy is not allergic to nuts) including seafood these foods are a great source of iron; she will also be given iron supplement to take on daily basis. Amy should go and see her pediatrician every three months to have her blood drawn to make sure that her iron deficiency anemia has improved. Iron deficiency usually is treated with iron tablets, syrups for children or injections; iron deficiency will last as long as its cause persists. Iron usually needs to be taken for many months to bring the levels back to normal. In this case we have Marcus a 5 year old African-American male who just moved to New York City, and is visiting his new pediatrician for a kindergarten physical. Marcus’ mother tells the nurse that she carries the â€Å"trait† and she wants Marcus to be screen for it. The â€Å"trait† is sickle cell which is a blood disorder that is inherited when there are two copies of the sickle cell gene in which one from each parent is present. Sickle cell disease is an inherited blood disorder that affects nearly 100,000 people in the United States. Sickle cell disease causes red blood cells to form into a crescent shape, like a sickle. The sickle-shaped red blood cells break apart easily, causing anemia; Sickle cell disease is most common in Africans and African-Americans. It is also found in other ethnic and racial groups including people from South and Central America, the Caribbean, Mediterranean countries, and India. Marcus needs blood a blood test done to see if he carries the ‘trait’ so he needs to give a blood sample. That blood sample is examined under a microscope, but sickle cell disease is diagnosed by a blood test call hemoglobin electrophoresis, which measures the amount of the abnormal sickle hemoglobin. Marcus has not had any episodes of the disease he will have to take preventative measures to avoid having complications or onsets of symptoms. Sickle cell causes the blood vessels to become clogged and the body tissues are deprived of oxygen and that will cause unhealthy organs and tissues. That is why Marcus will have blood test done to determine if carries the â€Å"trait’. In order to avoid any serious infection the pediatrician will have Marcus take penicillin until the age of 6 years old along with that he will be taking vitamin folic acid (folate) on a daily regime. Avoiding temperatures that are too hot or too cold should be avoided, Marcus must also drink plenty of water; also Marcus’ mom needs to take him to regular office visits in order to prevent the disease and to stay healthy. There is no cure for most people with sickle cell anemia. However, treatments can relieve pain and help prevent further problems associated with sickle cell anemia. Scientific research is being conducted to find ways to prevent cell. Thorough studies of gene therapy and ways to replace abnormal genes that cause sickle cell are being conducted on regular basis. There are treatments when people are in pain having fever, weakness or having hard trouble breathing, they will have IV treatments (intravenous) fluids and antibiotics. The sickle cell is passed from generation to generation in a pattern of inheritance; people with sickle cell have one normal gene and one defective form of the gene. According to the Mayo clinic a Bone marrow transplant offers the only potential cure for sickle cell anemia. But, finding a donor is difficult and the procedure has serious risks associated with, including death. Our last case is Richard who has noted over the past several weeks that he is having more bruises or ecchymosis, all over his body. After coughing this morning, he noticed tiny red marks all around his eyes. Richard could have a blood disorder that is called Thrombocytopenic it is a blood disorder that causes a reduction of platelets in the blood and it could be cause by certain drugs as heparin, histamine blockers, also this disorder also causes the blood not to properly clot and it is very important that Richard avoids any type of activity that will cause bruising and open wound injury. Richard will need a blood test to find out what is causing his blood disorder. He will need to visit his physician to have blood work done; the blood work will include a CBC, PTT, (Partial Thromboplastin Time), PT (Prothrombin Time) these test are done to evaluate the blood for its ability to clot, since that is what could be why Richard is bruised easily. Lab tests to determine the platelet count and clotting function may also be done. If indeed a diagnosed is confirmed then there is a treatment plan that will be discussed. Treatments can vary according to the cause. Corticosteroids may be used to increase platelet production. Lithium carbonate or folate may also be used to stimulate the bone marrow production of platelets. Again there is no cure for this blood disorder, but there are treatments which are steroids to help prevent bleeding by decreasing the rate of platelet destruction. These blood disorders have several things in common; there are no cures and no way to prevent them. Researchers are continually working very hard to find a way to prevent and hopefully cure these blood disorders. The best way to diagnose these blood disorders are to have blood test done to prevent and get treatment early in symptoms. But the most effect way with these blood disorders is by obtaining an early diagnosis as soon as symptoms are presented so a treatment can be started as soon as possible. How to cite Assignment: Blood Disorder, Papers