Identification Of Unknown Amino Acid

Extreme pH levels such as pH 2 and pH 12 breaks the hydrogen bonds between the

As shown in the graph above, a constant pH 7 was recorded throughout the increase of acid and base. With this observation, it was clear that the liver responded in the same manner as the buffer #1. Therefore, it can be concluded that liver has a buffer characteristic in it. Another solution named buffer #2 was tested with HCL and NaOH, which results had a similar pattern to the tap water, however the rate of change in pH was quite different. The rate of pH change in buffer #2 was gradual but a sudden drop from 8-3 when 20 or more drops of HCL were added, where tap water has a higher rate of change from 1-3 drops and then became constant from 6 drops onwards. The increase in pH for Buffer #2 occured after 10 drops of NaOH was added which was quite different from the rate of change in tap

When using different methods to measure pH levels there are some tools that can be useful. Some more than others but by putting into action the different methods it may determine which tools will work best and give the best results when testing the pH within a solution. The pH, which stands for the proportion of hydrogen ions in a solution, could be acidic (acidosis), neutral or basic (alkaline). The pH scale goes from numbers 1 through 14. A pH of 7 is neutral;

Introduction: The concentration of Hydrogen Ions in a substance is its pH. Hydrogen Ions (H+), and Hydroxide Ions (OH-) are formed when an electron jumps from one H2O atom to another. When a Hydrogen Ion is in an aqueous solution (a solutions with water as the solvent) it bond with an H2O atom creating H3O also known as Hydronium. A substance with more Hydrogen Ions than Hydroxide Ion is called a base. A substance with more Hydroxide Ions than Hydrogen Ions is called an acid. This can be seen on the pH scale below (Figure 1). A pH scale shows the number of Hydrogen

pH is a measurement of hydrogen ion concentration. It measures rather the solution is acid, base, or neutral.

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.

PH sensors are used in many scientific laboratories to measure the hydrogen-ion concentration of a liquid substance and to determine the basicity and acidity of a liquid. PH meters measure the electrical potential difference between a reference electrode probe and a pH electrode probe. Since these probes are very sensitive, they are required to be kept cleansed from contaminants. If exposed to contamination, one risks faulty or unreliable data, since their accuracy is dependent on a regular calibration and upkeep. To avoid this risk, and accurately measure hydrogen-ion concentration, the probes are kept in a buffer solution and calibrated before each use. [1]

Identifying this organic acid was an extensive task that involved several different experiments. Firstly, the melting point had to be determined. Since melting point can be determined to an almost exact degree, finding a close melting point of the specific unknown can accurately point to the identification of the acid. In this case the best melting point

the number of hydrogen ions in the blood, which decreases the pH of the blood. This is as a direct consequence

The diverse roles of amino acids: 1. Hormones (signaling type molecules)  Dopamine, thyroid type hormones 2. Metabolic Intermediates  Catabolic amino acids  Citrulline: key intermediate in the urea acid cycle, the pathway by which mammals excrete ammonia.  Ornithine: in urea acid cycle, precursor to arginine, disposal of nitrogen. 3. Osmotic effects (Osmolytes- organic compounds affecting osmosis, soluble in solution within a cell, play a role in maintaining cell volume and fluid balance.)  Ex: Antarctic fish utilize stores of amino acids to offset preservations of different ions. 4. Buffering Capacity  Zwitterion (means twin in German): A zwitterion is a chemical compound that is electrically neutral but carries formal positive and negative charges on different atoms. Zwitterions are polar and usually have a high solubility in water and a poor solubility in most organic solvents. o Often times the R group is charged.  Ex: Histidine (essential amino acid) the R group has a charge, pKa at pH 7.4. Modest change in pH results in change in charge; many proteins have a Histidine residue sitting in the active site. Changes ability to interact with substrate, which causes a profound change in kinetics.

Production of H+ will cause plasma pH to fall below 7.4. Normally, increases in H+ concentrations are buffered mostly by haemoglobin, however buffers can only resist small changes in pH. The HCO3- levels increase slightly, but are likely to still remain within normal levels of 22 to 26 mEq/L. This is because equilibrium changes in concentrations is slight compared to the large compensatory changes (1). Renal mechanisms can assist in excreting H+ and reabsorbing HCO3-.

An acid can be described as a substance that releases hydrogen ions in detectable amounts. They can react with several metals and have a sour taste. Hydrogen ions (protons) and anions are always produced whenever an acid is dissolved in water. The acidity of any solution is determined by the concentration of protons in it. Some examples of acids produced inside the human body include hydrochloric acid (HCL), acetic acid and carbonic acid. Acids that dissociate completely and irreversibly in water are known as strong acids. Weak acids dissociate incompletely and reversibly.

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.

First, three titration curves and three second derivative curves were created to determine the average pH at the half-equivalence point from the acetic acid titrations. Titration curves were used as visuals to portray buffer capacity. The graphs and a table, Table 1, that showcased the values collected were created and included below. The flat region, the middle part, of Figures 1, 2 and 3, showed the zone at which the addition of a base or acid did not cause changes in pH. Once surpassed, the pH increased rapidly when a small amount of base, NaOH, was added to the buffer solution. Using the figures below and

In 1909 S.P.L. Sorensen published a paper in Biochem Z in which he discussed the effect of H1+ ions on the activity of enzymes. In the paper he invented the term pH to describe this effect and defined it as the -log[H1+ ]. In 1924 Sorensen realized that the pH of a solution is a function of the "activity" of the H1+ ion not the concentration and published a second paper on the subject. A better definition would be pH=-log[aH1+ ], where aH1+ denotes the activity of the H1+ ion. The activity of an ion is a function of many variables of which concentration is one. It is unfortunate that chemistry texts use a definition for pH that has been obsolete for over 50 years.