Thin-Layer Chromatography of Steroid Hormones Essay Example for Free

Thin-Layer Chromatography of Steroid Hormones Essay The purpose of this experiment was to test the solubility of various steroids in order to obtain more information about their structure. An unknown was also given to be included in the experiment. The test that was performed was thin-layer chromatography which required a glass plate. The known steroids used in this experiment were estradiol, hydrocortisone, cortisone, corticosterone and deoxycorticosterone. Introduction Steroid hormones are a subgroup of lipids. They are found in one of the primary endocrine glands in the body, the adrenal glands, which are located directly superior to the kidneys. The structures of the adrenal glands begin with the outer layer known as the cortex. This region is most commonly referred to as the adrenal cortex and provides the gland with approximately 80% of its total mass. Within the adrenal cortex there are three layers: the outermost layer is known as the zona glomerulosa, the middle layer is known as the zona fasciculata, and the innermost layer is known as the zona reticularis. Each of these layers is comprised of many cells that synthesize and secrete hormones appropriately named the adrenocorticoids. The second portion of the adrenal gland is known as the adrenal medulla. It is the inner region and account for the remaining 20% in each of the adrenal glands. The adrenal medulla is responsible for the release of epinephrine and norepinephrine into the bloodstream. Adrenocorticoids include three types of steroid hormones. Each class belongs to a specific layer in the adrenal cortex and each class secretes specific hormones. The first group of adrenocorticoids is referred to as mineralcorticoids. These hormones are secreted by the zona glomerulosa and are responsible for the regulation of both the reuptake of sodium and the secretion of potassium. The mineralcorticoid used in this experiment was the more potent, deoxycorticosterone. Abnormal levels of minercorticoids can be associated with hypertension and can be induced by various problems, such as, low blood sodium, high blood potassium, cardiac failure, kidney failure, or even cirrhosis of the liver. The second group of adrenocorticoids is referred to as the glucocorticoids. These are produced by the second layer in the adrenal cortex, the zona fasciculata. The functions of glucocorticoids include stimulating gluconeogenesis through the use of amino acids and breaking down of muscle proteins. In this experiment the glucocorticoids used were hydrocortisone and corticosterone. These hormones are used medically to suppress the immune system by inhibiting the inflammation process. However, too much secretion of these hormones can be indicative of Cushing’s syndrome, pregnancy, and stress that comes from disease or other sorts of bodily trauma. The third group of adrenocorticoids that will be discussed are sex hormones. Sex hormones are not only secreted by the adrenal cortex. They are largely secreted in the reproductive system of each respective gender. Sex hormones can be further categorized into androgenic hormones, estrogenic hormones, and progestational hormones. Androgenic hormones are found predominately in the testes of the male, and there is it secreted by the interstitial Leydig cells. The most common and most powerful androgenic hormone is testosterone. Estrogenic hormones are only slightly different from their counterparts. Estrogenic hormones are identified by their 18 carbon ring structure whereas androgens are identified by their 19 carbon ring structure. Estrogenic hormones are secreted by the female reproductive organs known as the ovaries. The most potent estrogenic hormone is called estradiol and its release fluctuates throughout a woman’s menstrual cycle, with its peak volumes being around the time of ovulation. The last subgroup of sex hormones is called progestational hormones, or progesterone. Progesterone is responsible for the final maturation of the endometrium. Located in the ovaries, it is released from the corpus luteum during the luteal phase of the menstrual cycle and also increases in volume during pregnancy as the fetus progresses. Progesterone is different from the other two classes of sex hormones in that it is a 21 carbon ring structure. The modality used in this experiment was a chromatogram. Thin-layer chromatography is the type of chromatography that uses a small glass sheet covered in a thin layer of an adsorbent material. Once solutes are obtained, they are carefully placed on the glass sheet on the origin line. Then the glass sheet is soaked in a solvent for a certain period of time that varies with each chromatography technique. After it is through soaking, the solutes can be observed and the distance that each solute has moved can be measured. This value is obtained by using the R? ormula which takes the distance a solute travels from the origin line divided by the distance that the solvent traveled (this measure is known as the solvent front). This R? value can help determine unknowns as well. The final result of this experiment is known as a chromatogram, and depending on which technique is used, the steroids can be seen through regular light, or via a UV lamp. A UV light lamp was required for this experiment. Chromatography is a very useful tool in identifying the solubility properties of steroid hormones and revealing variants in hormone structure.

commentary Dred Scott Essay -- essays research papers

This commentary will focus on the impact of the Dred Scott decision in America. Dred Scott was born a slave in Virginia to the family of Peter Blow originally. The family moved to St. Louis and sold Scott to Dr. John Emerson, a military surgeon stationed at Jefferson Barracks. Scott traveled with Dr. Emerson to different areas such as Illinois and Wisconsin territories, where slavery was prohibited. This is because of the Missouri Compromise, this compromise was created to end expansion of slavery and permitted Missouri to entered as a slave state and Illinois was entered as a free state. Because Scott had traveled to free territory, he felt that he was a free man and sued to be free. The first case is against Emerson’s wife and is dismissed based on a technical issue, the second case Scott wins the right to be free, however the case is appealed to Wisconsin Supreme Court who disagrees with the lower court and Scott remains a slave. Scott lawyers filed suit in the U.S. Federa l Court and this time it’s against Mrs. Emerson’s brother whom took over the estate due to her remarriage, his name was John F.A. Sanford. The United States Supreme Court first hears the case in 1854 and then again in 1856. The case gains public and political attention. It affected the presidential election in which it would cause a candidate to agree or disagree with the high court. Congress begin debates on its power to control slavery specific territories, eventually they left it up to the high court ...

Kinetics Chemistry Lab

Rachel Smith Design Lab: Kinetics Lab Introduction: ! Background Information- Effervescent tablets reduce stomach acid and help treat upset stomachs. The familiar ? zzing you hear when you drop an Alka-Seltzer tablet into a glass of water is the result of a chemical reaction. After dropping the tablet into the water, the reaction causes the solid tablet to become dissolved and releases tiny bubbles of carbon dioxide. This reduces the time it takes for the medicine to work as it does not need to dissolve inside the body. Research Question: How does the surface area affect the rate of the reaction?Varaibles†¢ Independent: Surface Area †¢ Dependent: Rate of Reaction (time) †¢ Controlled: Water temperature, Volume of water, Concentration, Still water, and One tablet. Hypothesis: Increasing the surface area of the tablet will increase the rate of the reaction. Materials†¢ Effervescent Tablets (12) – 4 Per Trial, 3 Trials †¢ 150mL Beaker †¢ 80mL of Wate r per trial (3 trials) †¢ Mortar and Pestle †¢ Scalpel †¢ 100mL Graduated Cylinder (error + 0. 5) †¢ Stopwatch (error + 0. 1) †¢ Thermometer Procedure-! 1. Gather all materials needed for experiment. 2. Measure 80mL of water in the 100mL graduated cylinder. . Pour the 80mL of water from the 100mL graduated cylinder into the 150mL beaker 4. Let the water sit until it reaches the room temperature, use the thermometer to measure the temperature until it reaches around 26 degrees celsius. 5. Retrieve 4 effervescent tablets (for ? rst trial), prepare tablets: 1)leave it whole, 2) cut the tablet in half using the scalpel, 3) cut the tablet into fourths using the scalpel, and 4) completely grind up the last tablet with the Mortar and Pestle. 6. Place the whole tablet in the 80mL water in the beaker and immediately start the timer. 7.Wait until the tablet is no longer visible and stop the timer; record time in the data table, report any qualitative observations. 8. Pour the solution into the sink 9. Repeat steps 2-4 to prepare the water. Rachel Smith 10. Place the two halves of the tablet in the 80mL water in the beaker and immediately start the timer. 11. Repeat steps 7-9 to ? nish the reaction. 12. Repeat steps 2-4 to prepare the water. 13. Place the four quarters of the tablet in the 80mL water in the beaker and immediately start the timer. 14. Repeat steps 7-9 to ? nish the reaction. 15. Repeat steps 2-4 to prepare the water. 6. Place the completely ground tablet in the 80mL water in the beaker and immediately start the timer. 17. Repeat steps 7-9 to ? nish the reaction. 18. Clean up the work station and put all materials back in their correct place. 19. Using the data collected on the data table, calculate the average rate of reaction for each type of tablet to complete the reaction – keep in mind the uncertainties. 20. Make sure to show your work for step 19. 21. Then using the averages that were calculated in step 19, make a bar graph to show the relationships between the tablets. 2. When making the graph the BLANK goes on the x axis and the BLANK goes on the y axis. 23. Using the information from the relationships of the tablets in the graph and the averages, determine the relationship between surface area and the rate of the reaction. Data Collection: Rates of Reaction in Seconds (+0. 1) Whole Half Quarter Trial #1 Trial #2 Trial #3 Average in Sec Calculations: Step: Whole Half Quarter Powder Average Rates if Reactions in Seconds Add Divide 57. 0+55. 3+58. 5= 42. 2+41. 5+43. 2= 34. 9+41. 1+38. 4= 24. 3+25. 0+24. 6= 170. /3 126. 9/3 114. 4/3 73. 9/3 Final Average 56. 9 42. 4 38. 1 24. 6 57. 0 sec 55. 3 sec 58. 5 sec 56. 9+0. 175% 42. 2 sec 41. 5 sec 43. 2 sec 42. 4+0. 236% 34. 9 sec 41. 1 sec 38. 4 sec 38. 1+0. 263% Powder 24. 3 sec 25. 0 sec 24. 6 sec 24. 6+0. 406% Average Rate of Reaction in Seconds 60. 0000 Rachel Smith 45. 0000 30. 0000 15. 0000 0 Whole Half Quarter Powder Surface Area of the Tablet Pe rcent Uncertainty Calculations Step: Error / Time Multiplied by Percent Error Add Percent 100 Uncertainty Divide by Three Final Percent Uncertainty Whole 1)0. 1/57. 1). 00175 2)0. 1/55. 3 2). 00181 3)0. 1/58. 5 3). 00171 1)0. 1/42. 2 1). 00237 2)0. 1/41. 5 2). 00241 3)0. 1/43. 2 3). 00231 1)0. 1/34. 9 1). 00287 2)0. 1/41. 1 2). 00243 3)0. 1/38. 4 3). 00260 1)0. 1/24. 3 1). 00412 2)0. 1/25. 0 2). 00400 3)0. 1/24. 6 3). 00407 1). 175% 2). 181% 3). 171% 1). 237% 2). 241% 3). 231% 1). 287% 2). 243% 3). 260% 1). 412% 2). 400% 3). 407% .175+. 181 +. 0. 527/3 171= 0. 527 . 237+. 241 +. 0. 709/3 231= 0. 709 . 287+. 243 +. 0. 790/3 260= 0. 790 . 412+. 400 +. 1. 219/3 407= 1. 219 +. 175% Half +. 236% Quarter +. 263% Powder . 406% Graph: Graph Comparing Surface Area to the Average Rate of the Reaction Qualitative Data: ! When the tablet was dropped into the water the tablet began to quickly dissolve resulting in bubbles and the ? zzing of the water. Error Analysis: Rachel Smith ! Systematic er rors include 1) The experimenter not reading from the meniscus line, when determining the amount of water in the graduated cylinder was 80mL and when measuring the temperature of the water, 2) Not allowing the water to reach room temperature 3) The experimenter not completely ? ling the 100mL graduated cylinder with 80mL of water and 4) The experimenter not starting/stopping the timer at the right moment. ! ! Random errors include 1) The experimenter incorrectly reading the graduated cylinder 2) The experimenter losing some of the tablet while trying to cut the tablet into smaller pieces and 3) The experimenter not cutting the tablets into precise pieces. Conclusion & Evaluation: ! The goal of this experiment was to ? nd the relationship between the increasing surface and time.The hypothesis was that as the surface area increased the rate of the reaction would also increase. Through the experiment performed, it is visible through the graph that the hypothesis was proved to be correc t. As the surface area of the tablet increased the rate of reaction did as well. From the original size of the tablet to when the tablet was completely crushed into a powder the amount of time needed to complete the reaction diminished. Ultimately the hypothesis proved to be correct based upon the data retrieved from the experiment.

Essay on Media Violence and The Effects on Children

Does media violence have a negative effect on children? On September 11th, 2001, millions around the world crowded around televisions across the globe, watching the horrific scenes of terrorism that had struck New York City, Washington, D.C and Pennsylvania on that ill-fated and now infamous morning. Our sense of security and impenetrable protection crashed 110 stories to the shaken streets of New York City. We watched with shock and horror, disbelief and grief as the images were repeatedly flashed before our eyes, with the all the drama of the plane crashing through the World Trade Center and bursting into an indescribable ball of fire and of the surreal scenes of demolished piles of what used to be the Twin Towers of New York City. We†¦show more content†¦Government official and scientific experts agreed that the trauma incited by these images was detrimental to children. President Bush expressed his concern for the mental scars that could likely be inflicted upon children as a result of this prevalence of terrorism and violenc e in the media. It is apparent then that experts concur; the violent images permeating the media could likely have a negative effect on children, causing them to feel unsafe, and to live in fear for their own lives and those of their loved ones. In an interview with CNN, Dr. Jeffrey Mitchell reported that: nbsp;nbsp;nbsp;nbsp;nbsp; Children neurologically are not well suited to deal with extremes of trauma, so when they see this kind of stuff, right now it may look like some the movies they have seen on television. Except in this case people dont get up and act in the next (movie). In this case theyre injured because theyre injured or theyre dead because theyre dead. So it can be very traumatizing for children to see these images on TV. They dont understand what this is all about...So thats why Im suggesting that we not allow an excessive amount of TV for children at this particular point (Mitchell, 2001). The news is not the only source of violence for children. Our fictional television programming is responsible for significant exposure of children toShow MoreRelatedThe Effects Of Media Violence On Children873 Words   |  4 Pages According to the Media Education Foundation, once a child reaches eighteen years of age, they have witnessed around 200,000 acts of violence and 16,000 murders (jacksonkatz.com). Our society loves entertainment and a grand portion of this entertainment contains violence. Children constantly consume violent visuals, due to their prevalence. Majority of our society is uninterested in the effects of media violence since its effects do not show immediately. Misinformation is our greatest enemy in theRead MoreThe Effects Of Media Violence On Children974 Words   |  4 Pagesmany kinds of media, like Internet, video game, television and film. It is generally believed that some of the bad information such as violent content in the media can have a negative eff ect on people, and it can end up causing some social problem. It is clear that children are more likely to be influenced by media violence than other age groups because of their world outlook and personality are not formed. Furthermore is if media violence does have some profound influence on children, this will leadRead MoreThe Effects Of Media Violence On Children884 Words   |  4 Pagesis all this necessary to fabricate in the media? What are characters in movies teaching kids? What about the language in music talking about killing people and talking about violence like it’s the cool thing? What about new channels always talking about guns, bombs and threats to the public, is this what is influencing are children because they view it as a norm? Some may agree with this as others may disagree. Media violence is not the factor in violence today. Studies show that over 90% of homesRead MoreThe Effects Of Media Violence On Children1357 Words   |  6 Pagesthe graphic cruelty and violence. According to American Psychological Association, the harmful influence of media violence on children dates back to the 1950s and 1960s, and remains strong today. A child that watches violence or hears about violence can be influenced to become violent. Indeed, in reviewing the totality of empirical evidence regarding the impact of media violence, the conclusion that exposure to violent portrayals poses a risk of harmful effects on children has been reached by theRead MoreThe Effects Of Media Violence On Children1943 Words   |  8 PagesFor many years now, the media has been a big part of our lives. Almost everybody in the world is or has connected to it one way or another. It is a way for families and friends to have fun together, for interesting topics that people are interested in, or to just enjoy alone. However, there is a problem that can be seen across all types of media: violence. Violence can be seen as a distraught way to get over problems. There is judgement issues involved for violence. It is done by bullies in schoolRead MoreThe Effects Of Media Violence On Children2411 Words   |  10 PagesMedia Violence is definitely harmful to children as the exposure of media violence can desensitize children (age 6-12) to violence and in the real world; violence becomes enjoyable and does not result in apprehensiveness in the child. There have been several studies and experiments regarding the adverse effects of violence used in video games, television, as well as movies. With both preschool and school-aged children, studies have found that they are more likely to imitate the violence they seeRead MoreThe Effects Of Media Violence On Children2122 Words   |  9 Pagesexposed to various types of media, for example books or magazines, television, song lyrics, video games, and movies. Media often portrays, aggressive action, behaviour, and violence. This content can negatively affect not only adolescents and adults, but can have an even greater effect on children even from the moment they are exposed to it. Children who are exposed to violence in the media may display aggressive and violent behaviour. Young people especially children under the age of eight thisRead MoreThe Effects Of Media Violence On Children1903 Words   |  8 Pagesdepict different forms of violence. Some people feel that there is too much violence exposed in the media. Many studies have made the claim that the media is responsible for much of the violence seen in the world we live in. However, people have choices and responsibilities we cannot allow ourselves to blame it on other things such as the media. The violence seen in our media has an impact on both adults and children. Since children are also exposed to various forms of media, there has been additionalRead MoreEffects of Media Violence on Children2430 Words   |  10 PagesThe Effect of Media Violence on Children and Levels of Aggression. It has been said that children are like sponges when it comes to attaining knowledge. This seems to be true whether they are learning to speak or how to show emotion. Feelings and emotions become more imminent once children begin to go through adolescents. Children acquire the ability to aggression, sadness, and happiness more readily. Males typically exhibit higher levels of aggression then females according to some researchRead MoreThe Effects Of Media Violence On Children1270 Words   |  6 Pagesdifferent forms of violence. Some people feel that there is too much violence exposed in the media. Many studies have made the claim that the media is responsible for much of the violence seen in the world we live in (List and Wolfgang). However, people have choices and responsibilities we cannot allow ourselves to blame it on other things such as the media. The violence seen in our media has an impact on both adults and children. Since children are also exposed to various forms of media, there has been