The results of our experiment were similar to the actual isoelectric point of BSA with the exception of one data record. The calculated pI for BSA was approximately 4.5 after experimentation in comparison to 4.7, the real pI value of BSA. The isoelectric point was calculated after graphing the averages of each buffer solution and taking the x-intercept of the data. The isoelectric point detailed the pH at which the substance had a net charge of zero. The second strip of pH 6.0 with a value of +5mm, was omitted from calculations to improve the accuracy and precision of data. Buffers with a pH greater than the isoelectric move towards the negative end. Most of the buffer solutions with a pH of 4.7 and greater from the data, migrated to the negative
A cell is the fundamental building blocks of all living organisms. Cell’s consist of four biopolymers; protein, carbohydrates, lipids, and nucleic acids. Each macromolecule is a polymer that is formed from molecules known as monomers. In this experiment samples will be subjected through a variety of chemical tests using procedures that will detect the presence of each macromolecule; carbohydrates, protein, and lipids. The specific chemical tests that will be used during this experiment consist of the Biuret test which is a test used to determine the presence of peptide bonds in protein, which is the chemical bond that holds amino acids together. The test relies on a color change to confirm the presence of proteins. If proteins are present,
In part A, we can identify all of amino acid, Protein and peptide bond by used bond by used to Ninhydrin will detected amino acid by reach with alpha-amino group. In the experiment, all samples are give positive Result except urea because urea is ‘not amino acid or protein.So,the negative result of urea is correct that no change color of product.Glycine,glutamate and methionine give the light purple product. There are positive result show that all of them are amino acid. White cysteine ,Cosein and biuret give the light brown or yellow produch.there are also positive result but the result are different from another because cysteine contain di-sulfide bond. It's make on effect to reaction that can made the light yellow product. Casein is protein that contain a high number of proline residues that made the yellow product also the result of biuret is positive, give brown product from the reaction between ninhydrin and NH-group.For biuret test,alaline copper sulphate reacts with compound two or more peptide bond will give a pink or violet product as the
To prevent fluctuation in the pH, a solution known as a “buffer solution” was used in the experiment. Buffer solutions are mixtures of at least two chemicals which counteract the effect of acids and alkalis. Therefore, when a small quantity of alkali or acid solution is added the pH of the enzyme doesn’t change.
The titration curve of the unknown exhibited many characteristics, such as equivalence points, pKa of ionizable groups, isoelectric point, and buffer regions, that are particularly distinct to lysine. For unclear reasons, the pH during the titration did not reach the pH for pure 0.2 M NaOH nor 0.2 M HCl and normal equivalence points expected at two extreme ends of the titration curves for all amino acids were not observed. The titration of a phosphate buffer showed that the buffer capacity is directly proportional to the molarity of the buffer. However, our results showed that although the initial pH of the phosphate buffer was less than the pKa value, the measured buffer capacity was higher towards acid than base. The accuracy of the pH meter and calibration process was questioned under assumptions that the pH of the prepared phosphate buffer was actually above pKa.
For this experiment, titrations on a weak acid, acetic acid, and a buffer were performed. Acetic acid was titrated with NaOH in order to observe the half-equivalence point as well as the equivalence point. Then, the buffer and the buffered acetic acid solution prepared faced additional titration with NaOH and HCl to evaluate the differing buffering effects following the addition of a strong acid and strong base. Finally, the buffer’s buffering capacity was calculated. If the experiment were to be repeated, it would be interesting to observe the buffering effects following a titration between a weak base and a buffer instead with greater concentrations. The change in the concentration following the preparation of buffer with a weak base and its conjugate acid would pose for an interesting experiment to observe an increase in the buffering capacity.
Chemistry 102 is the study of kinetics – equilibrium constant. When it comes to the study of acid-base, equilibrium constant plays an important role that tells how much of the H+ ion will be released into the solution. In this lab, the method of titrimetry was performed to determine the equivalent mass and dissociation constant of an unknown weak monoprotic acid. For a monoprotic acid, it is known that pH = pKa + log (Base/Acid). When a solution has the same amount of conjugate base and bronsted lowry acid, log (Base/Acid) = 0 and pH = pKa. By recording the pH value throughout the titration process and determining the pH at half- equivalence point, the value of Ka can be easily calculated. In this experiment, the standardized NaOH solution has a concentration of 0.09834 M. The satisfactory sample size of known B was 0.2117 g. The average equivalent mass of the unknown sample was found to be 85.01 g, pKa was found to be 4.69, which was also its pH at half-equivalence point and Ka was found to be 2.0439×〖10〗^(-5). The error was 1.255% for equivalent mass and 0.11% for Ka. In other word, the experiment was very precise and accurate; the identity of the unknown sample was determined to be trans-crotonic by the method of titrimetry.
Salting out is the first isolation technique carried out for this lab. This isolation technique separates the Rubisco based on solubility. The method of salting out requires an addition of salt such as ammonium sulfate to the solution containing protein Rubisco to allow precipitation (Duong-Ly & Gabelli, 2014). The additional of ammonium sulfate to the Rubisco
An acid-base titration is the determination of the concentration of an acid or base by exactly neutralizing the acid/base with an acid or base of known concentration. This allows for quantitative analysis of the concentration of an unknown acid
Ionic compounds and covalent compounds have many similarities and differences. Ionic compounds are only formed with metals and non-metals. Covalent compounds are formed with non-metals. Ionic compounds have an overall neutral charge, but covalent compounds don’t have charge. Ionic compounds are formed when non-metals take electrons from metals. This gives both of them noble gas configuration. Covalent compounds are formed by two non-metals sharing their unpaired electrons, so they can mutually have noble gas configuration. What properties do compounds form when forming ionic and covalent bonds?
Table 2: Consists of color extract taken from a red cabbage for a natural indicator. The pH reading that was measured by using the pH meter and the result of the pH reading to determine whether the solution was acidic or basic.
The pH of a solution is the measure of the concentration of charged Hydrogen ions in that given solution. A solution with a pH lower than seven is considered to be acidic. A solution with a higher pH is a base. It is very important for organisms to maintain a stable pH. Biological molecules such as proteins function only at a certain pH level and any changes in pH can result in them not functioning properly. To maintain these constant pH levels, buffer solutions are used. A buffer solution can resist change to small additions of acids or base’s. A good buffer will have components that act like a base, and components that act like an acid.