Enzyme Catalysis Essay Example for Free

Enzyme Catalysis Essay Enzymes catalyze nearly all biochemical reactions in living cells (Hein, Best, Pattison, and Arena, 2005). As a catalyst, they regulate the chemical reactions by lowering the needed activation energy (Sackheim and Lehman, 1998). Catalysts facilitate chemical reaction but are not consumed, thus, can be used all over again. This function of enzymes is directly dependent on their three-dimensional structures and on the variables that affect their stereochemistry. It was believed that all enzymes are protein in nature but several findings showed that certain ribonucleic acids (RNAs) have enzymatic function (Hein et. al. , 2005). A typical organism has a thousand of biological simple or conjugated enzymes. A simple enzyme is made up of amino acid units while a conjugated one has both protein and non-protein parts that are called apoenzyme and coenzyme respectively (Hein et. al. , 2005). The substrate or substance by which the enzyme will act upon binds at the enzyme’s active site. This active site is about 1-5% of the total surface area of the enzyme (Hein et. al. , 2005). Catalysis follows that is usually describe as formation of enzyme (E) and substrate (S) complex, then, E-S complex decomposes to yield the product and the enzyme. Enzyme-catalyzed reactions are affected by several factors. This may be due to the variables effect on the stereochemistry of the enzyme and kinetics consideration. For instance, temperature affects the rate of all chemical reactions. The higher the temperature, the faster the chemical reaction takes place. However, enzymes coagulate in higher temperatures while lower temperatures results to low reaction rate. Thus, a particular enzyme best functions at its optimum temperature (Sacheim and Lehman, 1998). Concentration on the other hand, favors faster rate of chemical reaction. An increase in substrate concentration, hence, leads to a faster reaction until to the point wherein the enzyme is saturated by substrate. Moreover, every enzyme has an optimum pH range where it can function best (Sackheim and Lehman, 1998). Slight pH changes affect the polarity of the amino acid backbone of the enzyme resulting to changes in its catalytic function. In this simulation experiment, the catalytic capability of a hypothetical enzyme at different environmental conditions was investigated. The effect of temperature, pH, and substrate concentration on its optimal catalytic function were taken into consideration. In addition, the optimal temperature and optimal pH of the hypothetical enzyme were also determined. Moreover, the relationship between the enzyme concentration and the reaction rate was also explored. Procedure The spectrophotometer equipment was used in the simulation experiment in order to measure the amount of the product formed by the enzymatic reaction. The spectrophotometer is equipped with wavelength of light adjustment within 300-700 nanometre range, and percent transmittance (T) or absorption (A) of light by the sample. In addition, six different substrates labeled from A to F and six different enzymes also labeled from A to F were provided. The wavelength setting for each substrate was indicated on the vial and the clock above the substrate vials were used in setting the wavelength selector and in taking the time of the reaction respectively. Temperature, pH scale, a pipette, and a cleaning button were also made available. The substrate A and the enzyme A were used all throughout the simulation experiment. Optimal PH Five milliliter of enzyme A was added to 25 mL of substrate A and the spectrophotometer was set at 430 nanometer wavelength. This was done for every sample for 2, 4, 6, 8, and 10 pH values. The absorption for each sample was measured within one minute and 25Â ° temperature. Then, the graphical representation of data was made by plotting pH values against absorption values. Optimal Temperature Five millilitre of enzyme A was added to 25 mL of substrate A. This was done for 10Â °, 20Â °, 30Â °, 40Â °, 50Â °, 60Â °, 70Â °, and 80Â ° temperature values. The spectrophotometer was set at 430 nanometre wavelength and each sample was maintained with pH 8 value. Also, one minute absorption reading was allotted for every sample. Then, the temperature values were plotted against absorption values. Reaction Rate At this part of the simulation experiment, two mixtures of substrate A were prepared. The first sample was prepared by adding 5 mL of enzyme A into 25 mL of substrate A while the other sample was made by adding 25 mL of subtrate A with 15 mL of enzyme A. The spectrophotometer was set at 430 nanometre wavelength and the absorption reading for each sample was done for every 10 seconds within 2 minutes. The pH of each sample was maintained at pH 8 value. Finally, the graphical representation of time and absorption was made for each sample.

Whos Responsible for the Death of Eva Smith? :: An Inspector Calls J.B. Priestly Essays

Who's Responsible for the Death of Eva Smith? 'An Inspector Calls' is a play written by J.B. Priestly. Although the play was set in 1912, it was actually written in 1947. It was written after the events that were mentioned in the play, like the First World War and the sinking of the 'Titanic'. It is thought that J. B. Priestly's experience in World War One inspired him to write a story about how cruelly humans treat each other. In the 1910's there was a lot of cruelty and discrimination because of the different classes. The upper classes were cruel to the lower class because they were poorer and worked for the upper classes. Priestly wrote the play to make people aware of the social differences and how nasty people treat each other. If the upper classes were less pompous and treated the lower classes the same as everybody else, the country's wealth would be more evenly spread so there wouldn't be as much discrimination. 'An Inspector Calls' is a play which forces the audience to realise that every judgement made, every action taken, has an effect on another person. Priestly was well known for his involvement in human rights issues. He became known as 'The voice of the common people' The play 'An Inspector Calls' was written to show an audience about human cruelty. The inspector was there to show the family how nasty they are and he is trying to make them think about what they have done to make Eva kill herself. The inspector may have represented J.B. Priestly and he used the family to show the audience how he feels about the cruelty that goes on. The Inspector could have been a spirit, the name sounds like ghoul - Goole. He could have been representing the ghost of Eva Smith and he was trying to show the family how much they made Eva suffer. This can be shown by what the inspector said: "A pretty, lively sort of girl who never did anybody any harm. But she died in misery and agony-hating life-" and "She was here alone, friendless, almost penniless, desperate. She needed not only money but advice, sympathy, friendliness." The inspector may have represented the voice of conscience. Priestly based the inspector on his views of every day society. The inspector was annoyed with the upper classes because of the way they treated the lower classes. That might be the way Priestly thought and he was trying to get his points of view noticed by putting them into a play where many people would take notice. Priestly was also trying to say that society as a whole is responsible for tragedies, no one person

E-Business-Issues and Challenges

E-Business – Issues and Challenges Ashmita Paul Abstract In today’s business climate, e-business can have an impact on every facet of the organization, including supply chain management, leasing, non-cash payment, mail order commerce or the rise of service economy. As said by Lou Gerstner, ex CEO of IBM, â€Å"E-business is all about time cycle, speed, globalization, enhanced productivity, reaching new customers and sharing knowledge across institutions for competitive advantage†. E-business is transforming companies and industries, at an accelerating rate. Business cycles that used to be measured in years are now measured in days. This paper deals with the various issues of e-business as well as the challenges being faced. Issues can be technological and non-technological. Technological issues investigated include telecommunication, hardware, software and the availability of technical skill sets. Non-technological issues are often related to intellectual property concerns, copyright, trademark, credit/cash policies and privacy. As companies have embraced the internet as a business medium, they have discovered that their biggest challenge is not only establishing connectivity and infrastructure but is the safe and secure transmission and sensitive information. This paper focussed on emerging issues of e-business that are more high-up and stern in developing and emerging economies. An attempt has also been made in the paper to throw light on the challenges to e-business that are more related to strengthening success factors, establishing barriers to failure, diminishing barriers to success and fighting the failure factors. Key words: E-Business, Technological, Non-Technological, Challenges.

A Short Story Form Based On Ford s Idea - 1966 Words

‘Short stories want to give us something big but want to do it in precious little time and space’ (Richard Ford, 2007). Discuss how the form of the short story focusses on and elucidates a major issue, with illustration from, and analysis of, at least two short stories we have read or listened to on the module. The following essay will discuss the short story form based on Ford’s idea that short stories want to use a small amount of time and text, to convey greater issues. By considering the short story form in detail, how it works and how that relates to different texts, the concept of elucidating major issues through smaller ones can be thoroughly investigated. In the journal Short fiction in theory and practice, Ursula Hurley states†¦show more content†¦The conflict shown in the short story between the narrator and her grandmother as they explore the island, and compare the places they are from, acts as a smaller symbol for the larger conflict between the places they discuss, and the heritage of the young girl. Evelyn Hawthorne in the journal ‘Ethnicity and Cultural Perspectives in Paule Marshall’s Short Fiction’ (Hawthorne, 1986), implies that ‘the identity conflict of the Caribbean-American, as of other immigrants with a dual heritage, is an important issue which Marshall was one of the first to explore’ (Hawthorne, 1986, 45). This ‘identity conflict’ is portrayed through the young girl in the short story, who also has a dual heritage, her Caribbean heritage that her grandmother wants to teach her about, and her American heritage, which she tries to defend. As previously discussed, this larger conflict between the heritages can be seen through the conflict of the grandmother and the young girl. However, the specific dual Caribbean-American heritage conflict can be seen through the young girl herself and her thoughts, throughout the story. For