Titration of Amino Acids and Peptides

Titration of Amino Acids and Peptides Titration is the process used to analyze the acid-base behaviour of amino acids and peptides. A 0.25 g sample of unknown amino acid and aspartame were transferred quantitatively to separate 250-ml Erlenmeyer flask. 20.0 ml of distilled water was added to each flask using a volumetric pipette then the flask was swirled to dissolve the samples. Small increments of 0.200 M HCl were added to both samples to produce an acidic solution and then each sample was titrated by adding 0.200 ml of 0.200 M NaOH. The pH of the acidic solutions was measured from 1.5 until it reaches pH 11 and it was recorded in every addition of the base. On the Aspartame, the total volume of the base added was 8.0 ml and 29.6 ml on the unknown amino acid. Titration curves were constructed based on the pH values and volume added. The identity of the unknown amino acid was revealed to be Aspartic acid. A titrimetric profile of the amino acid and aspartame were drawn. INTRODUCTION Proteins are the most important class of biochemical molecules, next are carbohydrates and lipids. Proteins are the basis for the major structural components of animal and human tissue. Proteins are also the indispensable agents of biological function and amino acids are the building block of proteins. Amino acid is an organic compound containing an amino group (-NH2) and a carboxyl group (-COOH). Since amino acids contain both an acidic and a basic group, they undergo an intra molecular acid-base reaction and exist primarily in the form of a dipolar ion, or zwitterions. Amino acids are also amphoteric, meaning, they can react either as acid or base depending on the circumstances. There are basically 20 primary amino acids that serve as the backbone of most proteins. Peptide is a molecule that consists of two or more amino acid linked together by bonds between the amino group and the carboxyl group. Although their structures are less complex than the larger protein molecules, peptides have significant biological activities. Titration is a useful tool in determining the reactivity of amino acid side chains. Since amino acids contain an ionisable group, the predominant ionic form of these molecules in solution depends on pH. Titration of amino acid shows the effect of pH on amino acid structure. Titration is also useful in determining the isoelectric pH of the sample. MATERIAL AND METHODS A 0.250 g sample of unknown amino acid powder was placed on a 250 ml beaker using an analytical balance. 20.0 ml of distilled water was added to each flask using volumetric pipette and then the flask was swirled to dissolve the sample. Small increments of 0.200 M HCl were added to the dissolved sample using a syringe until the pH value is 1.50. Both acidified solutions were titrated by adding 0.20 ml of 0.200 M NaOH. The pH was measured and recorded at each amount of base that was added. The procedure was repeated until the pH of the solution reached 11.0. Same process was done using commercial aspartame. Titration curves of the unknown sample and that of aspartame were constructed using MS Excel. The unknown sample of amino acid was identified based on the pKa values and pI that were seen in the constructed titration curves. Titrimetric profiles of aspartame and the identified amino acid were drawn. Then the total percentage errors of the pKa and pI were calculated. RESULTS AND DISCUSSION The unknown amino acid was recognized by comparing its experimental value to 20 amino acids. In able to do that, a titration curve must be drawn. The unknown amino acid was recognized as glutamic acid and it was determined based on its pKa and pI value from the graph. In the titration curve of the unknown amino acid, it can be observed that at the pH reading of 2.16, 10.3 and 4.4 the graph shows an inflection curve making it the pKa values of the unknown sample. These reading were compared with the pKa values the 20 amino acids and it was observed that the experimental pKa values were close to the pKa values of glutamic acid. Identity of Unknown Amino Acid: Glutamic Acid Percentage errors between the experimental and theoretical pKa values of the Unknown amino acid were computed and the results were 4.11 %, 6.51 % and 3.53 % and the percentage error between the pI values of experimental and theoretical is 6.32%. The possible sources of errors were probably the inaccurate weighing of the sample and the measurement in adding HCl/NaOH. During titration, the prototrophic groups lose H+ successively as the pH reach their respective pKa values. The net charge of glutamic acid at the start of the titration is +1 and as each group loses H+ the net charge will decrease by one unit. The acidified Aspartame solution was titrated using 0.200 M of NaOH. The titration curve above shows the inflection points. These points are 2.5, 10.5 and 3.4. The possible sources of errors were the inaccurate weighing of the sample and the measurement in adding HCl/NaOH is not precise. During titration, the prototrophic groups lose H+ successively as the pH reach their respective pKa values. The net charge of aspartame at the start of the titration is +1 and as each group loses H+ the net charge will decrease by one unit. Other possible source of errors on the experiment was the inaccurate plotting of pKa values on the titration curve. Wrong pKa will cause the identity of the unknown sample to be incorrect. The buffering zones of glutamic acid are at 2.16 and at 10.3. In aspartame, the buffering zones are at 10.5 and at 3.4. Both are suitable as buffers on acidic pH. Aspartame has a taste that is close to sugar. It enhances the flavour and does not cause the teeth to decay. There is a scientific study that shows that aspartame is beneficial in weight control and it is helpful for individuals with diabetes because it allows them to please their taste for sweets without affecting their blood sugar level. Aspartame can also result in fewer calories, which helps people with diabetes, manage their weight. Aspartame hydrolyzes into its respective amino acid when heated. There are also unpleasant side effects of aspartame utilization which includes loss of memory, seizures, headache, blindness, protruding eyes, palpitation, depression, insomnia, diarrhea and skin rashes. Aspartame blocks and lowers the levels of serotonin, tyrosine, dopamine, nor epinephrine and adrenaline. As a result, it is typical that aspartame symptoms cannot be detected in laboratory tests and on x-rays.

Logitech and China

Logitech can be considered as a practical example of success in International trade. Logitech, with a well managed strategy could take advantage during these past few years of the globalization of production within different markets. First by outsourcing in Taiwan, then in China, Logitech has demonstrated a real capacity of adaptation to the fast moving actual business world. The company followed a strategy of continuous improvement based on reducing production costs, and focusing on innovation. By buying specific parts of its activities from suppliers in strategic locations, Logitech could benefits of cheap production cost making the brand to become more competitive in the market. Logitech obviously took the right decisions at the right time. When deciding to shift to Taiwan, because they needed more capacity of production, the company decided to adapt its needs to the opportunities offered by the global market. It can be imagined that Logitech’s strategies are carried by a really efficient team, making careful and updated environment analyses, examining all the possible opportunities for the company, at a particular moment, considering the actual position of the brand, the demand for the products, and focusing on the future of the company in a fast-changing environment. By deciding to outsource part of its activities in the US, Switzerland and Ireland for specific activities, Logitech demonstrated again a force of strategy. The global strategy of Logitech is very impressive and we can apply it to most of the Trade Theories studied on the chapter to illustrate the decisions which make Logitech’s strategy so successful.

Relationship between russian and the european union

Russia stretches over a vast expanse of Europe and Asia with an area of 17,075,200 square kilometres making it the largest country in the world in terms of land mass. This country   shares land borders with Norway, Finland, Estonia, Latvia, Lithuania, Poland, Belarus, Ukraine, Georgia, Azerbaijan, Kazakhstan, China, Mongolia and North Korea.Since the termination of the USSR in December 1991, Russia has become an influential member of the Commonwealth of Independent States. Russia's worldwide role decreased greatly compared to that of the former Soviet Union.Russia is an essential partner in terms of engaging and building a strategic partnership with.   The 2003 European Security Strategy has rightly placed this country as a key player on geo-political and security issues at global and regional levels.Russia plays an important role in the UN Security Council and has significant influence in the European neighbourhood and in Central Asia. It must likewise be noted that Russia is a major supplier of energy products to the EU.It may be considered to have a small market but Russia is a large market for EU goods and services, with considerable potential for growth. And if that's not good news yet, listen to this: Russia is a key ally in EU efforts in its fight against new threats to security, including terrorism, pollution, crime, illegal migration and trafficking.Russia and the European UnionThe European Union’s primary objective is to enlist Russia to build a genuine strategic partnership, founded on common interests and shared values to which both sides are committed in the relevant international organisations such as the UN, Council of Europe, and OSCE, as well as with each other in the bilateral Partnership and Cooperation Agreement (PCA). As Ivanov mentioned these interests and values involved democracy, the rule of law, human rights and market economy principles (2000, pp. 33).Shishaev says that the EU and Russia are already cooperating on various i ssues which include modernisation of Russia’s economy and its consolidation into the world economy, security and international issues (1999, p. 42).Shishaev further explains that â€Å"EU relations with Russia is guided on a large spectrum of particular EU policies, including external policies like the Common Foreign and Security Policy (CFSP) and trade policy; the external aspects of general EU policies such as on energy, transport, environment, etc.; the external dimension of freedom/security/justice activities; and the principles retained for development cooperation and assistance† (1999, p. 42).Likhachev reported that the common ground for EU relations with Russia is the PCA which came into force on December 1, 1997 for an initial duration of 10 years. This agreement shall extend beyond 2007 on a yearly basis.PCA sets the main objectives, establishes the institutional framework for bilateral contacts, and calls for activities and dialogue in a number of areas. The conditions of the PCA embrace a wide range of policy areas including political dialogue; trade in goods and services; business and investment; financial and legislative cooperation; science and technology; education and training; energy, nuclear and space cooperation; environment, transport; culture; and cooperation on the prevention of illegal activities. Rules of procedure for the dispute settlement provisions of the PCA were adopted in April 2004 (2000, pp. 20-24).The EU laid down its basic approach to relations with Russia in a â€Å"Common Strategy† in 1999 which was not extended beyond June 2004. An in February 2004, the Commission adopted a Communication which adopted measures to improve the effectiveness of EU-Russia relations, specifically in the wake of increased mutual dependence, the forthcoming enlargement, and the unresolved conflicts in some countries bordering Russia.The current institutional framework for relations with Russia as mentioned   above, is expec ted to change under the provisions of the new agreement with the view to creating a more concise and streamlined approach.During the Summit held in May 2003, the EU and Russia mutually decided to strengthen their cooperation by coming up with so-called four ‘common spaces’ in the framework of the PCA. It was agreed to make a common economic space; a common space of freedom, security and justice; a space of co-operation in the field of external security; as well as a space of research and education, including cultural aspects.Antonenko and Pinnick (2005, pp. 35-37) pointed out the ‘the purpose of the common economic space   is to create an open and integrated market between the EU and Russia which will bring down barriers to trade and investment and promote reforms and competitiveness, based on the principles of non-discrimination, transparency and good governance'.Among the wide range of actions that were perceived are a number of new dialogues. Cooperation is b eing stepped up on regulatory policy, investment issues, competition, financial services, telecommunications, transport, energy, space activities and space launching, etc. Environment, including nuclear safety and the implementation of the Kyoto Protocol, also figures prominently.Meanwhile, Antonenko and Pinnick (2005, pp. 124 – 127) also reported that work on a common space for freedom, security and justice has made a big leap with the end of negotiations on the Visa Facilitation and the Readmission Agreements which were signed during the recent the EU-Russia Summit last May 25 in Sochi, Russia. Ratifications are being done by both the EU and Russia.Working together on fighting terrorism and other forms of transnational illegal activities such as money laundering, drugs and human trafficking will continue as well as on document security through the introduction of biometric features in a range of identification documents.Forsberg (1998, pp. 201-204) illustrated that the comm on space on external security, meanwhile, underlines the shared responsibility of the parties for an international order based on effective multilateralism, their support for the central role of the UN, and for the effectiveness of, in particular, the OSCE and the Council of Europe.Currently, there are ongoing activities to strengthen cooperation in the five priority areas identified in the Road Map which include strengthening dialogue and cooperation on the international scene; fight against terrorism; non-proliferation of weapons of mass destruction (WMD); crisis management; and civil protection. Under the first priority, particular attention is given to securing stability in the regions adjacent to Russian and EU borders.Standing on the relations with Russia through its involvement in EU Research and Development activities and in particular the Framework Programme for Research and Development. The objective is to capitalise on the strength of the EU and Russian research communiti es and promote joint research activities in areas of common interest. Relationship between russian and the european union Russia stretches over a vast expanse of Europe and Asia with an area of 17,075,200 square kilometres making it the largest country in the world in terms of land mass. This country   shares land borders with Norway, Finland, Estonia, Latvia, Lithuania, Poland, Belarus, Ukraine, Georgia, Azerbaijan, Kazakhstan, China, Mongolia and North Korea.Since the termination of the USSR in December 1991, Russia has become an influential member of the Commonwealth of Independent States. Russia's worldwide role decreased greatly compared to that of the former Soviet Union.Russia is an essential partner in terms of engaging and building a strategic partnership with.   The 2003 European Security Strategy has rightly placed this country as a key player on geo-political and security issues at global and regional levels. Russia plays an important role in the UN Security Council and has significant influence in the European neighbourhood and in Central Asia. It must likewise be noted that Russia is a major supplier of energy products to the EU.It may be considered to have a small market but Russia is a large market for EU goods and services, with considerable potential for growth. And if that's not good news yet, listen to this: Russia is a key ally in EU efforts in its fight against new threats to security, including terrorism, pollution, crime, illegal migration and trafficking.Russia and the European UnionThe European Union’s primary objective is to enlist Russia to build a genuine strategic partnership, founded on common interests and shared values to which both sides are committed in the relevant international organisations such as the UN, Council of Europe, and OSCE, as well as with each other in the bilateral Partnership and Cooperation Agreement (PCA).As Ivanov mentioned these interests and values involved democracy, the rule of law, human rights and market economy principles (2000, pp. 33).Shishaev says that the EU and Russia are already cooperating on various i ssues which include modernisation of Russia’s economy and its consolidation into the world economy, security and international issues (1999, p. 42).Shishaev further explains that â€Å"EU relations with Russia is guided on a large spectrum of particular EU policies, including external policies like the Common Foreign and Security Policy (CFSP) and trade policy; the external aspects of general EU policies such as on energy, transport, environment, etc.; the external dimension of freedom/security/justice activities; and the principles retained for development cooperation and assistance† (1999, p. 42).Likhachev reported that the common ground for EU relations with Russia is the PCA which came into force on December 1, 1997 for an initial duration of 10 years. This agreement shall extend beyond 2007 on a yearly basis. PCA sets the main objectives, establishes the institutional framework for bilateral contacts, and calls for activities and dialogue in a number of areas.The conditions of the PCA embrace a wide range of policy areas including political dialogue; trade in goods and services; business and investment; financial and legislative cooperation; science and technology; education and training; energy, nuclear and space cooperation; environment, transport; culture; and cooperation on the prevention of illegal activities. Rules of procedure for the dispute settlement provisions of the PCA were adopted in April 2004 (2000, pp. 20-24).The EU laid down its basic approach to relations with Russia in a â€Å"Common Strategy† in 1999 which was not extended beyond June 2004. An in February 2004, the Commission adopted a Communication which adopted measures to improve the effectiveness of EU-Russia relations, specifically in the wake of increased mutual dependence, the forthcoming enlargement, and the unresolved conflicts in some countries bordering Russia.The current institutional framework for relations with Russia as mentioned   above, is expec ted to change under the provisions of the new agreement with the view to creating a more concise and streamlined approach.During the Summit held in May 2003, the EU and Russia mutually decided to strengthen their cooperation by coming up with so-called four ‘common spaces’ in the framework of the PCA. It was agreed to make a common economic space; a common space of freedom, security and justice; a space of co-operation in the field of external security; as well as a space of research and education, including cultural aspects.Antonenko and Pinnick (2005, pp. 35-37) pointed out the ‘the purpose of the common economic space   is to create an open and integrated market between the EU and Russia which will bring down barriers to trade and investment and promote reforms and competitiveness, based on the principles of non-discrimination, transparency and good governance'.Among the wide range of actions that were perceived are a number of new dialogues. Cooperation is b eing stepped up on regulatory policy, investment issues, competition, financial services, telecommunications, transport, energy, space activities and space launching, etc. Environment, including nuclear safety and the implementation of the Kyoto Protocol, also figures prominently.

Conjugate the Italian Verb Preferire