TRYPSIN LAB Essay Example For Students

TRYPSIN LAB Essay Title: The Effects of Substrate Concentration and Temperature on the Rate of Hydrolysis of the Enzyme Trypsin. Abstract: Quantitative measurements can relate both temperature and substrate concentration to the enzymatic activity of trypsin. By analyzing the data, it is suggested that at BAPNA concentrations below those corresponding to Vmax are rate limiting, as less active sights are available for adhesion. The values of Vmax and Km relate a temperate catalytic efficiency of trypsin. The temperature range of most efficiency for the enzyme was those between 36 and 54 degrees Celsius. Introduction: Enzymes are specialized proteins that aid in formation or breakdown of larger protein or multi-protein complexes. Trypsin is a pancreatic protease that digests proteins by hydrolyzing the peptide bonds in proteins. It has a high degree of specificity and will only hydrolize the peptide bonds that occur on the carboxyl side of the amino acids lysine or arginine. Generally hydrolytic reactions occur with the addition of water to breakdown a large protein into two protein fragments. Substrate concentra tion and temperature both would interfere and affect with the hydrolysis of Na-benzol-L-arginly-p-nitroanalide (BAPNA) into arginina and p-nitroaniline (PNA). An increase in the substrate concentration would most likely enhance the conversion into PNA, as collisions between the enzyme and substrate would increase. Temperature and pH can both influence the kinetics of an enzyme (Karp 100). Trypsin, being an organic enzyme, would probably work most effectively at temperatures consistent with biological life, falling in the ranges of 34C and 40C. The change in PNA concentration can be plotted against BAPNA concentration or temperature. To measure the kinetics of an enzyme, two variables can be found, Vmax and Km. Km is the estimated substrate concentration required for the reaction to advance at one half Vmax. Vmax is the maximal velocity of the reaction. These two values can be determined from the double reciprocal of the Michalelis-Menton equation or the Lineweaver-Burke Plot, with t he y intercept being 1/ Vmax, and the x intercept being -1/ Km. the equations are as follows:Michalelis-Mentonvelocity of reaction= Vmax (substrate concentration)/( Kms) Lineweaver-Burke plot 1/velocity= Km/ Vmax*1/sibstrate concentration+1/ VmaxMethods: Part 1: Effect of Substrate Concentration on Velocity Cuvette one was placed into the spectrophotometer containing the following: 0.1 ml of 10X buffer (400 mM Tris-HCl and 160 mM CaCl2), and 0.9 ml H2O. The absorbance was then read using a wavelength of 410 nm, and the absorbance number was used as a blank for the rest of the lab. The cuvette contained no PNA (the colored substrate) and hence is the reading when no reaction is taking place. The wavelength was chosen because the substrate is colored yellow, and a color other than yellow was needed to penetrate the cuvette, (410 nm is blue light). The absorbencies were then found using the following concentrations (in mM): 0.020, 0.040, 0.060, 0.080, 0.100, 0.120, 0.160, and 0.200. Th e results were then plotted with the absorbance being the dependent variable and the concentration the independent. The extinction coefficient, also called the molar absorption coefficient, could then calculated using the equation provided by the Biology 152 Lab Manual, E=A/cl were E is the extinction coefficient, A the absorbance, c the product of concentration, and l the length of the light path. With the extinction coefficient found, the rate of reaction could be found. We will write a custom essay on TRYPSIN LAB specifically for you for only $16.38 $13.9/page Order now 0.1 ml of 10X buffer and 0.4 ml of H2O were added to two cuvettes and gently mixed. 0.4 ml of 1 mM BAPNA was then added to each. To cuvette one, an additional 0.1 ml of H2O was added and mixed and placed in the spectrophotometer. This was the control to measure the hydrolysis of BAPNA in the absence of enzyme. In the second cuvette 0.1 ml of enzyme was added and mixed, then placed into the spectrophotometer. Readings of the absorbencies were taken every 15 seconds for ten minuets. The extinction coefficient was then used to convert each absorbance reading to PNA concentration. .u274dda8a04e60d77318424d0e2adb49c , .u274dda8a04e60d77318424d0e2adb49c .postImageUrl , .u274dda8a04e60d77318424d0e2adb49c .centered-text-area { min-height: 80px; position: relative; } .u274dda8a04e60d77318424d0e2adb49c , .u274dda8a04e60d77318424d0e2adb49c:hover , .u274dda8a04e60d77318424d0e2adb49c:visited , .u274dda8a04e60d77318424d0e2adb49c:active { border:0!important; } .u274dda8a04e60d77318424d0e2adb49c .clearfix:after { content: ""; display: table; clear: both; } .u274dda8a04e60d77318424d0e2adb49c { display: block; transition: background-color 250ms; webkit-transition: background-color 250ms; width: 100%; opacity: 1; transition: opacity 250ms; webkit-transition: opacity 250ms; background-color: #95A5A6; } .u274dda8a04e60d77318424d0e2adb49c:active , .u274dda8a04e60d77318424d0e2adb49c:hover { opacity: 1; transition: opacity 250ms; webkit-transition: opacity 250ms; background-color: #2C3E50; } .u274dda8a04e60d77318424d0e2adb49c .centered-text-area { width: 100%; position: relative ; } .u274dda8a04e60d77318424d0e2adb49c .ctaText { border-bottom: 0 solid #fff; color: #2980B9; font-size: 16px; font-weight: bold; margin: 0; padding: 0; text-decoration: underline; } .u274dda8a04e60d77318424d0e2adb49c .postTitle { color: #FFFFFF; font-size: 16px; font-weight: 600; margin: 0; padding: 0; width: 100%; } .u274dda8a04e60d77318424d0e2adb49c .ctaButton { background-color: #7F8C8D!important; color: #2980B9; border: none; border-radius: 3px; box-shadow: none; font-size: 14px; font-weight: bold; line-height: 26px; moz-border-radius: 3px; text-align: center; text-decoration: none; text-shadow: none; width: 80px; min-height: 80px; background: url(https://artscolumbia.org/wp-content/plugins/intelly-related-posts/assets/images/simple-arrow.png)no-repeat; position: absolute; right: 0; top: 0; } .u274dda8a04e60d77318424d0e2adb49c:hover .ctaButton { background-color: #34495E!important; } .u274dda8a04e60d77318424d0e2adb49c .centered-text { display: table; height: 80px; padding-left : 18px; top: 0; } .u274dda8a04e60d77318424d0e2adb49c .u274dda8a04e60d77318424d0e2adb49c-content { display: table-cell; margin: 0; padding: 0; padding-right: 108px; position: relative; vertical-align: middle; width: 100%; } .u274dda8a04e60d77318424d0e2adb49c:after { content: ""; display: block; clear: both; } READ: EToys EssaySeven tubes were prepared with the following a constant of 10X buffer, water, and enzyme. Added to the mixture were the following amounts (in ml) of BABNA before placing into the spectrophotometer: 0.05, 0.10, 0.20, 0.30, 0.45, 0.60, and 0.80. Corresponding amounts of H2O were then added in the following amounts (ml): 0.75, .70, .60, .50, .35, .20, and .00.The absorbencies were read every 15 seconds for 2.5 minuets. The PNA concentration was then plotted as a function of time. The slope of the linear portion of the graph represented the initial velocity of substrate hydrolysis as a function of time. The linear properties of the graph begin to wane as the BAPNA supply decreases over time. The increasing of PNA concentration will drive the initial velocity of the equation equal of lesser to Vmax and extent the linear portion of the graph. More trypsin would invariably provide more active sites to which BAPNA molecules can bind. The initial velocity of substrate hydrolysis is thus greater. Dropping the concentration would have the opposite effect, lowering the initial velocity of the reaction, limiting the linear region, as the former extends the linear region. Part 2: Effect of Temperature on VelocityObtain constant amounts of 10X buffer, H2O, BAPNA, and enzyme and place into cuvettes, saving the addition of enzyme until last. Acquire prescribed temperature by lowering the bottom of the cuvette into a bath for two minuets. When removed, add the enzyme, place in the spectrometer with the same 410 nm setting and record absorbances every 15 seconds for two and a half minuets. Repeat for the following temperatures (C): 10, 38, 45, 47, 50, and 54. Use data to determine the ideal temperature for enzyme action. The reaction rate against the BAPNA concentration of the hydrolysis of BAPNA displays a preliminary linear increase in the rate of reaction with a gradual decrease in the change of rate with substrate concentration to Vmax. The Lineweaver-Burke plot graph (Fig 1) estimated the value of Vmax to be 0.0627 mM/min, while the Km estimated was 0.413 mM. The equation for the double reciprocal was 1/velocity=(6.586) 1/substrate conc.+15.947. The curve representing the rate of reaction versus time demonstrated a low rate of reaction for the low temperature extremes, including 10C. The most efficient temperature demonstrated by our experiment was that of 54C. However when the temperature was increased to 56C, the reaction declined. Each graphical representation of the individual temperatures carried with it similar characteristics. Each possessed an initial linear relationship, and then each began to level off as the extinction coefficient was reached. The results of our first experiment displayed that as the concentration of substrate in a solution of enzyme increases, the rate of reaction increases. Enzymes work on the principal that substrate is formed by random collisions between enzyme and substrate. Hence more of either will increase the production of product. Our data showed this too is true, as product was formed at a faster rate with more enzymes, than of those solutions containing less. The values of Km and Vmax (0.413 mM and 0.0627 respectively) obtained from Fig 1 imply that trypsin has a moderate affinity for its substrate. Trypsin is also sensitive to temperature. Higher temperatures seemingly denature the enzyme, changing its structure and hence it is no longer able to fit in the substrates active site. Being a biological enzyme, it would assume to work well at temperatures associated with biological life, which it did, working optimally within the range of 36-54 degrees Celsius. Below this temperature, little activity was observed as the molecules were moving in a slower fashion, and the shape once again is changed. Karp, G. (1996) Bioenergetics. Pages 91-103 in Karp, G., Cell and Molecular Biology: Concepts and Experiments Second Edition. John Wiley Sons Inc., New YorkBibliography:

CUBA THE TOTALITARIAN REGIME THAT STILL GOES ON essays

CUBA THE TOTALITARIAN REGIME THAT STILL GOES ON essays CUBA THE TOTALITARIAN REGIME THAT STILL GOES ON When Columbus came to Cuba in 1492, he and his predecessors would probably never have imagined of this islands outcome within the centuries ahead. from conquering the country, to its independence, to the totalitarian regime put into it, all these major events have made the island what it is today. Before giving the whole story about the Communists, one must understand how the country was born so heres a little bit of a background history: Spain had conquered Cuba in 1511 under Diego Velasquez. Frequent insurrections failed to end Spains harsh rule. From 1868 to 1878 occurred the Armed rebellion known as the Ten Years War, led by plantation owner Carlos Manuel de Cespedes, a co-author of Cubas declaration of independence. After the loss of more than 200,000 lives, the revolt ended in failure. In 1933, Fulgencio Batista led a sergeants revolt that toppled the despotic rule of Gen. Grarado Machado and it was at that time that Batista became the most powerful man in Cuba. He was elected president in 1940 and made himself chief of state with dictatorial powers. Years of corrupt government, terrorism and embezzlement made by the United States led to a revolt in 1958 under the leadership of Fidel Castro. Batista fled to the Dominican Republic and the Fidelistas were in control of Havana. Castro then became premier at the young age of 32. At first people applauded the downfall of Batista and hoped that Castro could bring the country the prosperity it had wished for. Unfortunately, before long, people came to realization that the new regime had embraced Communism. At home, Castros regime has created the most repressive police state apparatus in the Western Hemisphere. Cuba is like the George Orwell nightmare predicted in the book 1984 except that this time the country is set in the tropics with Big Brother sporting a beard and ...

Human resourse practice in China Essay Example | Topics and Well Written Essays - 2000 words

Human resourse practice in China - Essay Example It also focuses on identifying the connections among these practices and highlighting the cultural dimensions of China. 1.1 Recruitment and selection In historical perspective, recruitment and selection of employees had little significance in China. They were following an iron rice bowl system, which has no policy of external labor market. All practices of HR such as recruiting, training, compensation and performance appraisal were handled by this one single system. However, after 1995, many countries started working on free labor market including China. This involved recruiting from all levels such as universities, colleges and schools, which is a common practice nowadays in China and many other developed countries. Presently, researches have noted that mostly in organizations 80% of employees get jobs on the basis of sources such as relatives, family, and friends etc. this is an illegal practice. This large amount of percentage should be reduced and other people should also be pref erred while recruiting and selection process. It have also been noted that most of the companies in China also prefer to transfer managers internally in order to fill the vacancies rather than hiring a person from outside (Child J, 2000). A selection criterion of China differs as compared to the other western countries. It focuses more on its cultural values i.e. guanxi, which means that there should be relationship among companies, employees and the government. Then only an organization leads to success. This culture focuses on the idea that employees should know that they are obliged to create a fit in their job and company should be able to retain the excess staff in case of new positions. This results to over employment in an organization. In recruiting and selection process companies should have more focus on skill and experience of a person rather than identifying that a person is Chinese or a foreigner, which is the common practice of Chinese companies. 1.2 Training and devel opment Education, training and development of employees lead to efficiency in performance and provide various benefits to the enterprise. In past it was identified that about 1.5% of workers in china had a suitable qualification, 27.3% studied till high school and 7.8% workers had technical knowledge. This shows that Chinese workers had lack of skills and were untrained. But after centralization of economy, China has concentrated more on the training and development of employees. Workers were provided internships and technical education in order to make them skilled persons. But a major problem identified in this program was that during training it resulted that most of the workers mismatched with their job, which lead to less work and productivity. Training programs were more concentrated on political issues in order to enhance the culture of China rather than technical education. This led to a drawback and indicates that the training system of China is mostly linked to theory rath er than practice. Workers are provided very narrow training aspect and they lack the ability to solve a problem in a practical way. Therefore, it can be said that the training and development process of China is passive and it does not produce creative and dynamic workers (Wei L & Lau C, 2005). Talented employees switch their jobs on two condition i.e. good salary or better carrier opportunities. But research indicated that in China employees are switching job because of better environment, compensation, knowledge, respectful position and carrier growth. In order to cope up with this situation Chinese management association introduced various courses on the education of management systems in many

Week 5 Discussion questions Essay Example | Topics and Well Written Essays - 500 words

Week 5 Discussion questions - Essay Example Sometimes management is naà ¯ve and they think that the same rules apply to a company in a large scale. With growth come a lot of hidden costs to monitor a larger operation. Enron was the largest energy producer in the world. The company got so big that a lot of lower level managers and accountants could not see that a huge scam was occurring right beneath their feet. I think that companies are more vulnerable to this phenomenon when they are in their early stages of development due to a lack of economic resources to implement proper internal control mechanisms. I think that employee growth is often not managed well as company start growth. For instances when a company has thousands of employees it become harder to implement control mechanisms to maintain a drug free environment because it is too costly to test all the employees. Firms can only implement random testing of a small population of the employees due to cost constraints. Sometimes firm underestimate the importance of experience and they hire too many college recruits at once. Bad management of human resources complicates human resource issues. I believe that one of the biggest changes in the accounting profession is that accountants have become bigger assets of the managerial staff due to their ability to analyze business information. The utilization of accounting information systems provides companies with precise up to date information that can be used to make informed business decisions. Technology has helped managers and accountants a lot. The accounting profession is changing in the United States due to the influence of new regulations that arrived in the 21st century such as the Sarbanes Oxley Act (SOX) of 2002. A branch of accounting that will grow a lot in the near future is auditing and forensic accounting. Sometimes when companies begin to growth they don’t pay adequate attention to their inventory numbers. This

Cryopreservation of Zebrafish Ovarian Follicles Essay

Cryopreservation of Zebrafish Ovarian Follicles - Essay Example The technologies in cryopreservation have undergone tremendous advances over the last decade. In addition, cryopreservation of oocytes and embryos is also being used as an effective means of treating infertility. In this technology, the clinical application seeks to ensure the optimal survival of embryos and oocytes that are subsequently thawed and stored for transfer . The aim of this practical experimentation is to compare the slow-cooling procedures with vitrification to analyze and evaluate the most effective and safest procedure as well as to endorse suitable recommendation for the adoption of best practices. To do this, it is necessary to test and calculate the viability for control, slow-cooling and vitrification samples. Determining the number of cells in the culture is also important for standardising culture conditions and performing accurate quantitation experiments . The use of viability test with hemacytometer and typan blue staining will enable us to determine the cell number, the correctness of which is inevitable for accurate test results. Live cells appear colourless and bright under phase contrast, while the dead cells sustain blue stains and are non-refractive. To facilitate accuracy and consistency of cell counts, we have used a viability counting system. This involves counting viable, live and dead cells in one or more large corner squares and recording the cell counts. In order to obtain an accurate cell count, 40 to 70 cells will be counted during the test phase. Therefore, it may be necessary to count more than one large corner square. The controlled technique, which is the conservative method used for the purpose of cryopreservation of cells and tissues, is based on the slow-cooling approach. It needs to be appreciated that a large number of non-sensitive cells can be preserved in liquid nitrogen with little damage through slow-cooling

Future Directions of Health Care

Future Directions of Health Care In the future the health care system faces several challenges. In stirring ahead in a strategic direction challenges they countenance are: technology advancements, health care reform and legislation, access to health care, advancing age of population and maintaining a skilled workforce. These regions afford challenges and there are a great deal requirements for reforms and changes. I will address in this paper five areas with challenges in strategies organizations and health care can become accustomed to obtain a strategic direction. The use of information technology (IT) in healthcare includes a wide range of technologies integrated in sharing and managing electronically information of patient as a substitute of records of paper which have the prospect for errors. IT has the prospective to develop safety of patient, quality of health care, effectiveness, and collection of data. This can aid to prevent costs rising with sturdy statistics that can establish itself. â€Å"Our country’s IT infrastructure of healthcare will facilitate and control these significant efforts-making probable the types of basic changes in delivery and access of health care projected in the fresh health care law†. (Buntin, 2010). For health care organizations there are health care incentives payments that can exhibit employ of EHR’s in an efficient and safe manner. Consecutively to meet the criterion for incentive payments, hospitals and physicians have got to exhibit evidence of significant use of technology whilst ex ecuting the subsequent: Certified EHR Technology-Utilisation of a certified product as established by the Health and Human Services Department (HHS), which has got to be incorporate the employ of electronic structure, Information Exchange-EHR have got to be connected in a way that offers health information electronic exchange to advance the health care quality, this comprises promoting synchronization of healthcare, reporting on measures by means of EHR have got to conform with reports of submission on quality measures of clinical. Physicians and Hospitals that implement EHR systems will advantage mainly. Physicians can earn extra above time by leveraging a Medicaid or Medicare program of incentive. Providers might obtain benefits beneath merely 1 of the 2 programs. Physicians and Hospitals must adapt their strategic direction to put into practice this technology in their organization consecutively to obtain the incentive program benefits. This counterbalances the technology costs a nd prevents them from cutbacks in funding of Medicaid and Medicare. The Affordable Care Act of 2010 marks a fresh period in health care of American. This Act will commence to have a constructive outcome on business owners, families, and employees. It decreases the premiums price in the course of tax relief. Policy makers have extensively afforded with means to construct costs of health care affordable and yet offer quality care. Physicians are worried above the health care high costs and that it â€Å"is not connected with high prominence and effectiveness in the services delivery or improved outcomes of health†. (Moseley, 2009, p.1). Future budget reductions to academic medicine intend challenges. Interventions of Prevention are a substitute to health care reform improvement. Reforms must be spotlighted on the issue of coverage, increasing quantity, increasing value, with a foremost spotlight on maintaining the healthy population. In due course the objective must be to improve on the bills of health care in the course of costs regulation, per formance measurement, extension of coverage, increase of sponsored government- insurance, and inducements for wellness programs. Each American must have access to affordable quality, coverage of health insurance. Millions of Americans devoid of coverage are deprived of access to desired care, medications by prescription, and additional essential services. â€Å"Not merely has the figure of uninsured increased, the increase has as well excessively affected the majority susceptible groups†. (Bloom Canning, 2011, p.1). Obstacles that the uninsured countenance is the distinction between preventative cares and need for further composite medical care. The financial effect is brutal and a lot of people effort to meet up their daily requirements. Strategies that firms can deem comprise: providing a group of skilled individuals to assist take advantage of participation in programs of public health insurance. Statistics require to be computed consecutively to sufficiently recognize the uninsured demographics. Offering free clinics and additional information on healthcare that is being offered will support to con struct improved outcomes of health. The objective is to resolve problems generated by cultural, geographic, and additional precise barriers. All the states consecutively to move forward must embrace services of community based that are provided in the course of the Affordable Care Act. â€Å"Even though a healthcare organization countenances no competition in any way, it had to depend on world about it changing-both the external and internal environments†. (Moseley, 2009, p.9). There are a lot of challenges in offering finance costs and needs of health care for the aging populace This is since further people are living longer healthier life owing to medical technology advancements. The elder age groups are on the increase and will carry on rising in a growing trend. A solution to this concern is to capture data with particulars on data of demographic similar to specific age with respect to productivity, to employment, capabilities, and links amid aging and macroeconomic performance to estimate superior results. As people age they stay in the labor force longer and their needs of health are different from individuals who are younger. As the segregation develops amid the elderly population, the matter of maintaining and educating, a skilled work force in the industry of health care is definitely a rational concern. Resources can be described as tangible or intangible- idle sitting, they merely do not add to productivity in a great deal. â€Å"What creates a distinction is what they are able of achieving when they are in operation or action. This hidden prospective of resources comprises a firm’s competencies. An ability that is activated is an activity†. (Moseley, 2009, p.40). Health care is a labor intensive industry that needs all levels of skill sets. In a strategic business unit Managers take into deliberation when hiring, the mainly efficient mix of staff that can accomplish the broadest workload in their resources. The amalgamation of skill sets and job descriptions required for every job in the organization is one mean to get extra for the money. A few of the skills and duties might extend bey ond into diverse areas of the SBU’s. Employers require investing in a skilled labor force if they are to meet up their financial objectives, particularly with the challenges of the present economic surroundings. With the job market challenges, forging local and state partnerships with employers consecutively to advance inferior skilled workers is vital. Offering reimbursement of education as an advantage to employees to acquire a higher degree is important. Advancing the improvement of lower skilled workers can be simpler when labor is in demand. Employers yet have got to maintain skilled and low skilled workers. It is significant to access training to advance employer’s competitiveness and productivity, performances of workers, and opportunities of future job. Building a relationship of team allows providers to retain, train, associate, work in the course of hard times, and grow when the economy permits. In America there are a lot of challenges faced by health care today. Organizations of Health care can make use of strategies to become accustomed to these challenges. It is vital to carefully examine the challenges we countenance and accustom strategies to these challenges. To meet up these challenges we can make use of experience and technology. Strategies can aid to prevail over hurdles and incessantly improve on the process. References Bloom, D.E., Canning, D. Fink, G. (2011). Implications of Population Aging for Economic Growth. (Report no. 64). Boston, MA: Harvard Initiative for Global Health. Buntin, M.J. (2010). Health Information Technology: Laying the Infrastructure For National Health Reform. Health Affairs. ABI/Inform Global, 1214-1219. Moseley, G.B. III. (2009). Managing Health Care Business Strategy, Sudbury, MA. Jones and Bartlett Learning Inc.

Got Zinc? :: Essays Papers

Got Zinc? According to recent statistics, zinc is the third most commonly used nonferrous metal in the United States. This unassuming metal was among the first minerals exploited by Man, used as a decorative material for thousands of years, although it never achieved the fame and notoriety of other metals such as gold or silver. In more recent times, new extraction and processing methods have allowed Man to produce higher-quality zinc than ever before, and to use it in an astonishingly high number of chemical and high-tech applications. The term â€Å"zinc† was not in use until the 16th century, at the earliest. The ancient Greeks called it â€Å"pseudargyras,† meaning â€Å"false silver,† and made very little use of it (Mathewson 1). The unassuming bluish-gray mineral was given a warmer welcome by the Romans, who were already using it to make brass by â€Å"about the time of Augustus, 20BC to 14AD†; the Romans used, not purified zinc, but the mineral calamine (â€Å"zincky wall accretions† from caves) and fused them in a crucible with bits of copper to make their brass (Mathewson 1). Around the world, zinc was being exploited by the Chinese civilization as well, although documentation of Asian use of zinc does not come until the 7th century of AD, from Kazwiui, the â€Å"Pliny of the Orient.† Kazwiui, â€Å"who died in 630AD, stated that the Chinese knew how to render the metal malleable and used it to make small coins and mirrors† (Mathewson 2). The discovery and us e of zinc, then, was widespread in ancient times and through the Middle Ages. However, it seems that it had not yet been used for anything much more practical than a mirror, a fact that would very quickly change in the 18th and 19th centuries as higher-grade zinc became available and new applications presented themselves. One of the most common applications of zinc in its early days was as a component in roofing. A report was presented to the Institute of British Architects in 1860 that revealed â€Å"that nearly every roof laid in Paris during the previous fifteen years had been covered in zinc, and this included famous buildings such as the Louvre and the Hotel de Ville† (Porter 73). The report was presented because British architects feared that they would lose technological pace with architects from the European mainland if they did not learn to take advantage of this valuable resource, which became increasingly fashionable.