A Guaiacol Dye-Coupled Reaction Reports That Catalytic Activity of Peroxidase Isolated from Fresh Turnip (Brassica Rapa) Increases as Temperature Rises Essays

A Guaiacol Dye-Coupled Reaction Reports That Catalytic Activity of Peroxidase Isolated from Fresh Turnip (Brassica Rapa) Increases as Temperature Rises Essays A Guaiacol Dye-Coupled Reaction Reports That Catalytic Activity of Peroxidase Isolated from Fresh Turnip (Brassica Rapa) Increases as Temperature Rises Paper A Guaiacol Dye-Coupled Reaction Reports That Catalytic Activity of Peroxidase Isolated from Fresh Turnip (Brassica Rapa) Increases as Temperature Rises Paper Enzymes are proteins which serve to reduce the activation energy required for biological reactions (Russell and others 2010). This allows biologically important chemical reactions to occur rapidly enough to allow cells to carry out their life processes (Russell and others 2010). Enzymes are made of one or more polypeptide strands, which individually or as an associated complex take on a three-dimensional shape. When properly associated, these shapes form the active site and other supporting structures that allow enzymes to be effective catalysts (Nelson and Cox 2005). Temperature represents the average kinetic energy in an object or solution (Russell and others 2010). This energy causes rapid movement of dissolved particles, such as enzymes and substrate molecules, increasing the chances that they’ll contact each other in such a way as to allow a chemical reaction to occur (Nelson and Cox 2005). The kinetic energy may also influence the folding of the enzyme. If the weak and strong bonds involved in stabilizing the protein structure are disrupted, denaturation of the protein can occur, eliminating the enzyme’s effectiveness (Nelson and Cox 2005; Russell and others 2010). This experiment will investigate the effects of temperature on the enzyme kinetics – that is, the rate of an enzyme’s catalysis – of peroxidase isolated from turnip. Plant peroxidases are involved in lignin formation, which is part of the cell wall (Cosio and Dunand 1985). Turnip roots contain peroxidases which are enzymes that can be easily extracted, and because peroxidases can liberate oxygen from hydrogen peroxide, their activity can easily be measured in the laboratory (Pitkin 1992). The rate of oxygen release is followed by measuring the rate of oxidation of guaiacol, which turns brown in the presence of oxygen and thus can be quantified in a spectrophotometer (Nickle 2009). We hypothesize that as we increase the temperature of reaction, kinetic energy will increase the frequency with which peroxidase engages hydrogen and the rate of guaiacol oxidation will increase. Because turnips grow in cool climates, often below 24oC (Pollock 2009), we expect that the optimal temperature for enzyme activity will be around room temperature or cooler, and temperatures in excess of this will cause denaturation of the enzyme and a concurrent loss of enzyme activity. METHODS AND MATERIALS A store-purchased turnip was scrubbed and rinsed with tap water. A razor blade was used to cut a 0. 5 g piece of tissue from the cortex. This was placed in a mortar along with 50 ml phosphate extraction buffer (0. 1 M, pH 7) and a pinch of sand. The tissue was ground to a slurry and then filtered through cheesecloth to form the extract used for all experiments after standardization. To ensure peroxidase was extracted from the turnip and that the reagents were suitable for the experiment, a positive control was performed. 2 ml of enzyme was added to a test tube containing 3 ml buffer, 2 ml H2O2, and 1 ml guaiacol dye. After quickly inverting twice to mix the fluids, the contents darkened. Standardization was performed to correct for differences in extraction techniques and tissue enzyme content. Three volumes of enzyme (0. 5, 1. 0, and 2. 0 ml) were tested. To ensure reactions did not begin prematurely, reaction components were placed into two separate test tubes. These were labelled â€Å"a† and â€Å"b† for each volume of extract, where â€Å"i† contained 0. 5 ml (dilute), â€Å"ii† held 1. 0 ml (medium), and â€Å"iii† had 2. 0 ml (concentrated) extract each (Table 1). The contents of paired tubes were combined in the tube containing the enzyme at â€Å"time zero†. This tube was mixed by inverting twice before 1 ml was transferred to a cuvette which was placed into a Genova spectrophotometer so the rate of absorbance change at 500 nm could be calculated. The concentration which gave the largest constant absorbance change (as shown by plotting absorbance over time) was used for subsequent experiments. The slope of each line in the plot was measured to determine the rate of guaiacol oxidation. The sample containing 0. ml fulfilled this criterion (data not shown). For all trials, the â€Å"a† tubes contained 2. 0 ml H2O2 and 1. 0 ml guaiacol, and â€Å"b† tubes contained 4. 5 ml buffer and 0. 5 ml enzyme extract. These were placed into the appropriate equilibrated water bath (see below) for 5 minutes prior to mixing and measuring their absorbance changes. For the temperature experiment, water baths were equilibrated at the desired temperatures of 4. 5oC, 10oC, 22. 5oC, 50oC and 80oC. To create the 4oC temperature, a beaker of water was placed in the refrigerator. Both â€Å"a† and â€Å"b† tubes were placed in racks in the appropriate water bath for 5 minutes prior to the time for them to be mixed together. Mixing was performed as described above, and the spectrophotometer was again used at 500 nm light. To determine if high temperature will alter results by degrading reagents (such as causing H2O2 to spontaneously release oxygen or make guaiacol oxidize independently of enzyme activity), we created a duplicate control tube (Table 1) and heated it to 80oC for 15 minutes. This negative control id not show an increase in absorption compared with the unheated control tube, so we concluded that the temperatures only affect molecule movements in the experiment. A similar test was done with the 4oC temperature and again no difference was measured. Three replicates were for each temperature. Rate of absorption change was established for each, and standard deviations between trials at each temperature were determined using Excel 2000 so ftware. RESULTS The positive control turned brown / beige constantly and continuously over about 1. 5 minutes. This was quite apparent to the naked eye. Controls exposed to high or low temperature without enzymes present did not show a different absorption than the control that remained at room temperature (data not shown). Reaction rate at lower temperatures was lowest at 4. 5oC at 0. 25 A500/min. This increased as temperature rose until a peak rate of 0. 52 A500/min at room temperature (22. 5oC) was noticed. At 50oC, the rate of oxidation declined to0. 39 A500/min and a reaction rate of 0. 05 A500/min was measured at 80oC (Figure 1). DISCUSSION The results indicate that enzyme activity does indeed increase as the temperature of the reaction is raised. The optimal temperature must lie between 10 and 50oC, but most likely is near temperature, possibly slightly cooler as turnips naturally grow in temperate climates (Pollock 2009). Enzymes are typically structured to function in a particular environment; usually one in which it normally functions (Russell and others 2010). The large standard deviation noticed for values collected at 10oC suggests that the true optimum may lie below room temperature. More measurements at this temperature could refine these values, giving a more precise average at this temperature. To find the optimal reaction temperature more accurately, a series of temperature intervals, perhaps 2oC apart and spanning 10oC to 50oC could be measured. It would be interesting to compare the precise optimal temperature for turnip peroxidase activity to the average temperature at which turnips naturally grow. A study that compares this to a peroxidase extracted from a tropical plant might also prove to be interesting. Investigating the reversibility of a weak thermal denaturation might also prove interesting. Thermal energy probably affects weak bonds, such as the hydrophobic, hydrophilic, and ionic associations, to the largest extent (Russell and others 2010). Denaturation might be prevented by stabilization with covalent linkages within and between polypeptide strands (Anfinsen and Haber 1961). Enzymes that are particularly susceptible to thermal damage are often supported by chaperonins or other proteins which can repair the denatured enzymes (Morimoto and others 2009). We plan to next identify the effects of denaturation, and whether it can be reversed by subsequent cooling. SUMMARY Plant peroxidases cause peroxides to break down and release oxygen. The rate of oxygen release can be calculated by observing the amount of oxidation that occurs with guaiacol insolution with peroxidase and its substrate. Enzyme activity was determined at 4oC, 10oC, 22oC, 50oC, and 80oC by measuring darkening of guaiacol. The highest amount of oxidation was recorded at 22oC. Enzyme activity was absent at 80oC, suggesting the enzyme denatured at this temperature. Enzyme activity correlates with the cool temperate conditions natural for this plant.

Henry Clay Should have been Pr essays

Henry Clay Should have been Pr essays I chose Henry Clay as the person who I think should have been president instead of these four other men. These other men were incompetent, they lacked leadership, and they each didnt have much support. None of them had much drive or motivation to be a good president, and as for a couple of them, they didnt have much political background at all. Henry Clay, on the other hand would have made a fantastic president instead of these four men. Even though he had already run for president three times, and lost, he still had the potential to be a great president. He had a vast background in politics. He had so much to do with what was going on that time in politics, it seem as if he never died (, from our pages of our history book that is). Henry Clay was a great man and I believe that he stood head-and-shoulders above the rest of the presidents of the 1850s. He was a great man who was secretary of state under John Quincy Adams and an unsuccessful candidate for the presidency in 1824, 1832, and 1844. He was one of the most popular and influential political leaders in American history. His genius in the art of compromise three times resolved bitter political conflicts that threatened to tear the nation apart, winning him the title The Great Pacificator. Clay was born on April 12, 1777, in Hanover County, Virginia, to a middle-class family. After studying law with the eminent George Wythe, Clay, at the age of 20, moved to Lexington, Kentucky, where he developed a thriving practice. He was blessed with a quick mind, a flair for oratory, and an ability to charm both sexes with his easy, attractive manner. Clay, who was ambitious for worldly success, married into a wealthy, and socially prominent, family and soon gained entry into Kentucky's most influential cliques. While still in his 20s, he was elected to the state legislature, in which he served for six years, until 1809. ...

Kindergarten Classroom Design and Child Development Research Proposal

Kindergarten Classroom Design and Child Development - Research Proposal Example The paper justifies the Montessori system by intensively exploring relevant literature, explaining the significance of the learning environment. The paper gives literature on a supposedly Montessori-inspired school layout, material, tools and the environment, in general. It also explains the need for a special setting for child development and the overall impact on the children (Montessori, 1964). The final section drafts a Montessori curriculum proposal for CWLAK. Children are today growing in a highly technological space. The children get exposed to the sophisticated electronics like Kindle books, and the doors open automatically, and the playing toys are digital and creative. There is the need for the early childhood to embrace technology into the early childhood classrooms (Barron et al., 2011). Scientific reports have indicated the benefits of exposing the children to the technological concepts early in childhood to avoid stereotypes and other related challenges when they grow up (Madill et al., 2007). Over a long time now, there has existed the increasing interest to bring change to the early childhood education by children classroom design that conforms to the technological changes. Best practices and new technology learning standards for incorporating technology into the early learning classrooms design. Teachers from all corners of life have shown interest in innovating ways to integrate technology into their curricula (Montessori, 19 64). Dr. Maria Montessori, an Italian, experienced educator, and trained physician came up with an educational pedagogy about 100 years ago. The system adopts a child-centred approach to education where the children undergoing the study are subject to scientific observations from childhood to adulthood. The method has been quite a success in diverse cultures across the globe. The American education system is bedeviled with many negatives (George, 1978). Implementing a Montessori style education that embraces the

Case Study Assignment Essay Example | Topics and Well Written Essays - 2500 words - 2

Case Study Assignment - Essay Example He further argues that the development department is capable of producing the software within the stipulated time since one of the employees at the department told him that they have extra time to develop such kind of software. Kelly Thomas argues that the reason as to why they cannot develop the software by August is because, based on his analysis of two years ago, when the company had more people, every support engineer was allocated a client after every one hour and as a result, the product in the market was of high quality and needed less support. Currently, the engineering development department has a shortage after 25 percent of the total staff was laid off and thus the remaining personnel needs more time to create the software since most of them are involved in the engineering support department for customers. Chris argues that the sales and revenues of the company are shrinking and to maintain the strengths and productivity of the company, there needs to be a 15 percent cut in the budget of the company. Chris further argues that it is possible to achieve a 15 percent cut in the budget without laying-off of staff and thus Total Corporation of the employees of the department is needed. The argument made by Cliff O Connor is sound. This argument is based on statistics and records of the company and thus he foresees the future based on past and current trends. For instance, Cliff argues that the current revenue of the company based on sales and service ratio is 50:50. This argument can only be made if there is an available statistical data to provide proof. In conclusion, the argument made by Cliff is very logical. The argument made by Pat Lambert is unsound. It is based on predictions and no available record is shown to support his line of reasoning. Pat argues that customers will be happy if the prototype is in the market by August despite its incompletion. Normally, if a product is released in the market and it does not offer value

Bibliography on the Mexican Muralist Movement Essay Example for Free

Bibliography on the Mexican Muralist Movement Essay As an instructor for the Yale-New Haven Teachers institute Maria Cardalliaguet Gomez-Malaga has posted the contents of her Curriculum Unit 06. 02. 01. The Idea behind a final for this class is a discussion of how Modern Mexican, Latino/a, Chicana/o art during the twentieth century turned revolutionary propaganda of the 1920s and 1930s, into a significant 20th century art form to young Chicano artists and activists. These artists developed a strong new Mural Movement that has had strong influences on the social, political and cultural development to support social activism during the 1960s. Her curriculum enabled me to find a starting point in the development of a thesis where I believe this Art form â€Å"The Mural† is able to describe a historical picture of life from one society to another through a Painted Medium. This thesis is preliminary in scope and needs to be defined more precisely in its description of historical life, though it is a beginning or a starting point for additional research. Campbell, Bruce. Mexican Murals in times of Crisis. Tucson: University of Arizona Press. ISBN 0-8165-2239-1. This book traces the ongoing critical contributions of mural arts to public life in Mexico to show how post-revolutionary murals have been overshadowed both by the Mexican School and by the exclusionary nature of official public arts. By documenting a range of mural practices—from fixed-site murals to mantas (banner murals) to graffiti—Bruce Campbell evaluates the ways in which the practical and aesthetic components of revolutionary Mexican muralist have been appropriated and redeployed within the context of Mexicos ongoing economic and political crisis. I think I can show how art can be used by public officials to influence public perception of political cause’s Author: Eva Sperling Cockcroft; Holly Barnet-Sa? nchez; Social and Public Arts Resource Center. Venice, Los Angeles, Calif. Signs from the heart : California Chicano murals Publisher: Venice, Calif. : Social and Public Art Resource Center : Albuquerque : University of New Mexico Press, 2001,  ©1990 In this book the authors began as just photographers collecting of pictures of Chicano murals for a family album. This would outgrow the picture taking phase as they discovered the social significance as these photos would become a nationwide photo documentation of powerful community based art. The book only one part of SPARC’s collection of mural slides is significant in that it helps to show the shift from Mexico to the United States as the center of mural production in the world. Art and Identity in Mexican and Chicano Social Movements by Edward J. McCaughan. http://bss. sfsu.edu/emccaughan/art_and_identity_in_mexican_and. htm This paper presents a comparative analysis of artwork produced in the context of social movements waged by Mexicans and Chicanos (U. S. inhabitants of Mexican descent) during the two decades between the mid-1960s and the mid-1980s. Young artists played a central role in projecting the public identity and agendas of powerful social movements that emerged in Mexico and among Chicanos in the United States in the 1960s. This paper is a good starting point for me in that the issues young artists were trying to depict are described in greater detail with the inclusion of female artists in the paper with internationally born artists I feel I have the material to start a solid project. Art and social change, or is it the ability of that art to provoke change in society’s view of? A view of what? Is this racial, social, class, or cultural differences among groups of people that art changes the perceptions of? I still am faced with a question that I would like to have answered for myself!

Yanomamo Essay -- Anthropology

Yanomamo The Yanomamo are a tribe of twenty thousand who live in about two hundred and fifty widely dispersed villages in Brazil and Venezuela. It was first thought that the Yanomamo were a group of hunter-gatherers, but contrary to that thought they actually cultivate their own crops for food. They also hunt and forage, but only as needed. While the Yanomamo travel for several weeks when the jungle fruits and vegetables are ripe, they are a tribal society settled in villages, which break into small groups to go off on collecting expeditions. During such expeditions, game such as wild pigs, large and small birds, monkeys, deer, rodents, and anteaters, are hunted. The bulk of the Yanomamo food, more than eighty percent, is grown in their village gardens. The size of the garden is dictated by the size of the family it must feed. Because village headmen will have the responsibility of entertaining visitors and sponsoring feasts, they plant and care for larger plots. Plantain is their most important domesticated crop. Manioc, taro, and sweet potatoes are also cultivated along with cane, used for arrow manufacture, and tobacco, a crop of central importance. All women, men, and children chew tobacco daily and guard it jealously. The Yanomamo word for being poor is literally translated as without tobacco. Cotton is al so grown in the village gardens to provide the materials for hammocks and clothes. The Yanomamo envision the universe as having four layers hovering at...

Wives as Deputy Husbands

â€Å"Wives as Deputy Husbands† by Laurel Thatcher Ulrich Article Review â€Å"Wives as Deputy Husbands† by Laurel Thatcher Ulrich was written to give the author’s opinion on the roles of women in the 17th and 18th century. Some historians thought women were merely there to do housework and take care of the children. They thought they were helpless. On the contrary other’s thought they were very involved in various affairs such as: blacksmiths, silversmiths, tinworkers, shoeworkers, tanners, etc. They thought they may have been very independent.However, this article is used to understand how households were run and how women fit into both female and male roles. The author’s thesis of this article is to inform the reader that women had more roles in colonial times than people rarely consider. Ulrich’s contention is that â€Å"the husband was in control of the external affairs and of the family, a husband’s decision would incorporate hi s wife’s opinion, and should fate or circumstance prevent the husband from fulfilling his role the wife could stand in his place† (Paragraph 4. ).Women didn’t only depend on their husband. She was not helpless. Her commitment to her husband did allow him to be able to trust her with difficult tasks that a servant couldn’t be trusted with. A wife specialized in housekeeping skills but it also included the responsibilities of being a deputy husband. Ulrich says â€Å"Economic opportunities were limited for women; however, female responsibility was a very broad topic† (Paragraph 8. ). A woman could do any task as long as it furthered the good of her family and her husband deemed it acceptable.Wives could double as their husbands and became respected companions and shared the spouse’s authority. There was no sharp division between home and work in the colonial time period. Many people worked on a farm which also doubled as their home. This was al so true for male and females, their spaces overlapped. While the husband was around her responsibility was limited. When he was absent her responsibility was more weighted. If a woman became a widow, and she had no sons, and chose not to remarry she could inherit the deceased spouse’s estate.Many of the male’s responsibilities were less desirable to a woman than doing housework was. This work may prepare her to function competently in a male’s world, though. This article is specific to female roles. The textbook and class discussions/lectures mainly taught about the people of colonial America as a whole. We learned a lot more about men’s roles and female responsibility wasn’t mentioned very often. The article taught me that women were very important to not only the household but the entire family.In her husband’s absence she would take on his responsibilities as well as the household one’s and not only be able to survive but thrive. I think it was important to read this article because both women and men were present in this time period. Without women there would be no men (literally), so why would we study the important of one? To understand he time period I think all genders and races need to be studied to a certain extent. The strengths of this article were that Ulrich added many examples to help understand how not all women were shrew and servile but rather very independent.A weakness was that she also presented arguments from the opposing sides which in some cases were slightly confusing. Yes, it does fit into the prevailing interpretation because men weren’t present in every situation and when they weren’t women were to maintain the household and affairs. This information is indeed different that what I previously learned about gender roles; women stayed at home to cook, clean, and take care of children while men worked. Overall, this article was very informative and helped me understand how families worked together to be successful in the colonial time period.