Rf Value

In this investigation, a TLC plate and ethyl acetate (solvent) were used to measure the Rf values of four different solutions of Tylenol, Anacin, Acetaminophen, and Acetylsalicylic acid. The value of Rf depends on the strength of the intermolecular forces that exists in molecules. The stronger the intermolecular forces are, the harder the solvent moves the molecule up, resulting a small Rf value. In contrast, molecules with weak intermolecular forces tend to have a high Rf value.

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

In both experiments, there was one environment that the enzyme worked best it. The graphs show that in the salt experiment 4% salt concentration was the optimum environment for the enzyme, and pH 6 buffer solution was the optimum pH environment for the enzyme. In the other environments the enzyme did not work as fast, therefore not creating as much product. The hypothesis was that the enzyme would work the most efficiently in the most neutral environment. The data does support this hypothesis; therefore we would accept the hypothesis. The neutral state for pH is pH 7, so the enzyme would be most active at exactly pH 7. With pH 6 buffer solution, the enzyme is working, but after pH 7, the enzyme begins to denature at becomes less effective. For the salt experiment, the hypothesis was that the enzyme would be more productive in the solution that had the least salt concentration. As the salt concentration increase, the enzyme would be being to denature. In this experiment, the hypothesis was incorrect, so it had to be

When the pH is not at its optimum, the differing pH's will disrupt the bonding between the R groups of the amino acid causing its structure and the shape of the activation site to change

After the trial ran for 10 minutes, we measured the distance travelled by the solutes and the distance travelled by the solvent. The distance the solvent travelled was 5.3 cm. The unknown solute travelled 4.1 cm, the Vis-a-Vis solute travelled 4.9 cm, the sharpie solute travelled 5.4 cm, and the Just Basic solute travelled 5.3 cm. By dividing the distanced travelled by the solute by the distance travelled by solvent we calculated the Rf value for each pen type. The unknown had an Rf value of 0.77, the Vis-a-Vis had an Rf value of 0.92, the Sharpie had an Rf value of 1.0, and the Just Basic marker had an Rf value of

1. Explain why you can’t fully test the lipase activity in tube 5. _Measurement of lipase activity uses a decrease in pH. Because the pH in Tube #5 is already very low, it is hard to tell if fatty acids are released.__

To improve the results from the experiment buffer solutions that were not whole pHs could have been used e.g. pH 4.5, 5.5 etc. This would have provided more reliable results as a wider range of results would have been produced. Using pHs with decimals would also help to more accurately determine the optimum pH as the optimum may have been above or below the pH stated in the hypothesis; 8. In this experiment however the optimum is taken at 8 because the graph does not rise again.

The PHCs in injected samples were separated by a Phenomenex (Torrance, CA) Kinetex C18 (100mm x 4.6 mm; 2.6 µm particle size) reverse-phase column. The mobile phase consisted of 10 mM ammonium acetate and 0.1% formic acid in water (A) and 100% acetonitrile (B). The gradient conditions were 0–0.5 min, 2% B; 0.5–7 min, 2–80% B; 7.0–9.0 min, 80–98% B; 9.0–10.0 min, 2% B; 10.0–15.0 min, 2% B at a flow rate of

The solution has been dechlorinated and adjusted to be slightly acidic. Place 75 mL of the solution in each of three labeled beakers. Obtain an animal organism, small fish, and a plant organism, Elodea. One beaker will be the control and will not have anything in it. Place exactly 25 mL of water in a 50-mL graduated cylinder. Place each organism in a cylinder and note the increase in volume above the original 25mL. The increase equals the volume of the organism. After taking measurement, cover each beaker with the plastic film. Place the beaker containing the Elodea in the dark by covering it with aluminum foil. Allow organisms to respire for 15 min. Gently remove the organisms from the beakers and return them to their original culture bowls. Then add four drops of phenolphthalein to the contents of each beaker. The solutions should remain clear because the solutions are acidic. Using a dropper bottle, dispense NaOH into the contents of the beaker drop by drop. Thoroughly mix the contents of the beaker after adding each drop. Continue adding drops until you first notice that the solution turns pink. Repeat for each beaker with at the living organism until the solution is the same shade of pink as the

When studying chemisty, you must grasp how reactions can form acids or bases, as well as what effect that has on pH. A basic understanding of chemistry is important in biology, because living things are composed of matter.

Our first step was that we boiled the samples, A&M Std , & Kaleidescope Std. for 5min. in water bath, then we loaded the samples into the wells following the guide given which was as follows: 1- 10 ml of laemmli buffer, 2- 10 ml of molecular weight, 3- 10 ml of salmon, 4- 10 ml of tilapia, 5- 10 ml of catfish, 6- 10 ml of shrimp, 7- 10 ml of actin and myosin, and 8- 10 ml of the laemmli buffer. To load each sample, we used a P-200 (yellow) micropipette tip to withdraw 10 ml of each protein sample from its tube and gently transferred it into the designated well. After loading all samples, on both of the gels we then placed the lid on the tank, and insert the leads into the power supply, matching red to red and black to black. We ran the gel for 45 minutes at a constant voltage of 115V. When the gels were finished running, we discarded the buffer from the inner chamber, we released the cams, and removed the gel cassettes from the assembly. We laid each gel cassette flat on the bench with the short plate facing

3. The tubes are allowed to incubate in a 37˚C water bath for 1 hour. The final pH of the solutions is tested and the amount of protein digestion is estimated using a scale of (+++), (++), (+), and (-) by

The “E” solution ended up having the most spots because it was the pigment fragments. The Rf values could be calculated for all of the spots by taking the distance traveled by the spot and dividing it by the total distance traveled by the solvent front. The calculations are as shown:

= PH changes affect the structure of an enzyme molecule and therefore affect its ability to bind with its substrate molecules. Changes in pH affect the ionic bonds and hydrogen bonds that hold the enzyme together, which naturally affects the rate of reaction of the enzyme with the substrate. On top if this, the hydrogen ions neutralise the negative charges of the R groups in 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.