Beer's Law Lab

Figure 1. Results recorded from experiment. After every 15 seconds for four minutes, the absorbance was recorded.

Abstract: The purpose of this lab is to separate and identify pigments and other molecules within plant cells by a process called chromatography. We will also be measuring the rate of photosynthesis in isolated chloroplasts. Beta carotene, the most abundant carotene in plants, is carried along near the solvent front because it is very soluble in the solvent being used and because it forms no hydrogen bonds with cellulose. Xanthophyll is found further from the solvent font because it is less soluble in the solvent and has been slowed down by hydrogen bonding to the cellulose. Chlorophylls contain oxygen and nitrogen and are bound more tightly to the paper than the other pigments.

(5 points) My results show that the Carotene ( orange) pigment had the highest molecular weight. ~~10. From the chromatography lab, which pigments were soluble in the acetone? (5 points)

The chemical compounds that were used to make the solutions in this part of the experiment are: Tin (II) Chloride, Hydrochloric acid, and Sodium Chloride. The new solutions that were made had values that were given in a table in the Laboratory Manual. Similar steps were performed in this part of the experiment that were also performed in the first part. The solutions were put into cuvettes, that were then put into the colorimeter machine, which displayed the absorbance, transmittance, and time values. After this information was collected it was put into an Excel spreadsheet and a graph of the time versus absorbance was generated.

By removing one milliliter of the stock solution to the first test tube, and repeating the same process for the other two tubes allowed us compare concentrations and know what the dilution factor would be when placed into the dialysis tubing. All three tubes had the same amount of water (4mL of H2O) added. Once the solution for each test tube was mixed well, we transferred 2 mL of each concentration into the dialysis bag. We secured each piece (3 in total) of the dialysis tubing to ensure that once the concentration was added that it would not leak out of either end. Three stir plates were used, all set at the same speed, and the dialysis bags filled with different concentrations were added. Before we began to measure the absorbance rate, we did take a sample of the water immediately after placing the dialysis tubing into each beaker. We observed each beaker over a period of 25 minutes. At each five-minute interval, we removed one milliliter of the solution and placed it into a cuvette. The cuvette sample was then placed in the spectrophotometer to calculate the absorbance rate of each sample. After each sample was measured, all data was recorded in the lab manual. Once all measurements had been recorded we used the absorbance rate to help calculate the concentration. The light that is absorbed when using the spectrophotometer is usually relative to the concentration of a specific

For lab 12, it is hypothesized that chlorophylls a and b are present in a plant leaf and contribute to the starch production in photosynthesis. Also, products of photosynthesis will be present in leaf tissue exposed to red and blue light wavelengths for several days, but a decreased presence in leaf tissue exposed to green and black light wavelengths. In lab 13, it is expected that since chlorophylls a and b are more polar and smaller molecules than the anthyocyanins and carotenoids, they will travel higher up the chromatography paper than the other pigments.

concentration, record the absorbance readings at a fixed wavelength, and plot the absorbance vs. concentration data. The wavelength of 520 nm was selected for experiment Part

When the Framers of the U.S. Constitution met, they did not intend to write the U.S. Constitution, they met to fix the Articles of Confederation. The Articles was too weak and could not support the nation either domestically or abroad. After the Framers had worked on the Articles for a while, they realized they need a whole new document; and they started over. While the Framers realized the need for a strong federal government, they also intended to protect its citizens from a monarchial government such as the England government. The Framers decided that people needed to be citizens of both the nation and their respective states. However, the Framers did not want any one person or group to have total control over any aspect of the

The same solution of 0.5 ml BSA was then added from test tube 1 to the test tube 2 after being properly mixed, and from test tube 2 the solution was being added to test tube 3, and so forth all the way up to test tube 5, with the same exact procedure. From the last tube, we then disposed the 0.5 ml solution. After above procedures, we now labeled another test tube “blank”; 0.5 ml blank distilled water was purred into the tube with the serial dilution of 1:10. We also had a tube C labeled “unknown” with the same 0.5 ml of solution. And after adding 5ml of Coomassie Blue to each tube (1-5) and to the blank, the result of absorbance was read at 595 nm.

Does religion affect how people view others? The book The Scarlet Letter is about a woman named Hester who was an adulteress and has a baby from this that she would name Pearl. She is scorned for this and is forced to wear an “A” on her chest. Later in the book, we find that the man seen as most divine my the community, Reverend Arthur Dimmesdale, is the father of Pearl and has not told the community. Much like the Puritan community, the Saudi Arabian Muslim community is very strict because of its religion.

Data were recorded and then the correction factor was placed. To determine actual absorbance, the correction factor reading was subtracted from the readings of “A” tubes. All data were recorded, then averages were used to create tables in

Light, Color, and Solutions Lab In this experiment, the relationships between wavelength, absorbance, concentration, and cell path are explored through separate, smaller experiments. These relationships can be combined to derive a single equation known as Beer’s Law. This equation is then used to identify an unknown solution’s formula weight.

Using the Beer-Lambert Law, it can be interpreted that variation of the concentration in relation to the constant and the path length of the cuvette will be the sole factor in changing the absorption rate of a solution, since the length of the cuvette remains 1 cm throughout the duration of the experiment. A calibration curve that compares the values for the absorbances and the concentrations of the yellow and blue dye can be found in figures 1 and 2 respectively. Figure 1. Shows the calibration curve for the absorption relative to the concentration (M) of the yellow dye Figure 2. Shows the calibration curve for the absorption relative to the concentration (M) of the blue dye Theoretically, both curves should show a linear line that starts

Using the yellow tube, which included everything but starch, as the blank, each group zeroed their spectrophotometer. This was done so that any absorbance observed depends only on the amount of starch present, not on any other reagents (buffer, IKI). To zero the spectrophotometer, the wavelength was first set at 580nm, using knob 3 (45). Next, the groups made sure that the light next to “transmittance” was lit, and the chamber to be tightly closed. Having the chamber empty & closed tightly provides reference for the darkest condition possible. Using knob 1, the transmittance was turned until it read 0.0 (45). Before the groups used their blank test tube to zero the spectrophotometer, each needed to wipe the tube with kimwipes to ensure a clean reading. Turning knob 2, each group was then instructed to zero the absorbance, 0.000. Upon removing the blank, each trial was inserted into the chamber (46). The

For unknown 1, we did 4 dilutions at the 4 concentrations listed in table 3. At 2μl of unknown, triplicate absorbance readings were taken and the average absorbance was 0.6. On the other hand, no further dilutions needed to be done for unknown 2, so three absorbance measurements at 10μl were taken. The average absorbance for unknown 2 at low concentration was found to be 0.37. Since the average absorbance at low concentration for 2 unknowns were found, we used equation 2 below to determine their concentrations. The best-fit line of the linearity part of the standard curve produced this equation.