AP Biology Lab Four: Plant Pigments and Photosynthesis 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. …show more content…
Replace cuvette 2 into the foil sleeve, and place it into the incubation test tube rack. Turn on the flood light. Take and record additional readings at 5,10,and 15 minutes. Mix the cuvette's contents just prior to each readings. Remember to use cuvette 1 occasionally to check and adjust the spectrophotometer to 100% transmittance. 14) Obtain the unboiled chloroplast suspension, mix, and transfer 3 drops to cuvette 3. Immediately cover and mix cuvette 3. Insert it into the spectrophotometer's sample holder, read the percentage transmittance, and record it in Table 4.4. Replace cuvette 3 into the incubation test tube rack. Take and record additional readings at 5, 10, and 15 minutes. Mix the cuvette's contents just prior to each readings. Remember to use cuvtte 1 occasionally to check and adjust the spectrophotometer to 100% transmittance. 15) Obtain the boiled chloroplast suspension, mix, and transfer 3 drops to cuvette 4. Immediately cover and mix cuvette 4. Insert it into the spectrophotometer's sample holder, read the percentage transmittance, and record it in Table 4.4. Replace cuvette 4 into the incubation test tube rack. Take and record additional readings at 5, 10, and 15 minutes. Mix the cuvette's contents just prior to each readings. Remember to use cuvtte 1 occasionally to check and adjust the spectrophotometer to 100% transmittance.
At five minute intervals over the next fifteen minute period, record the color intensity of the solution of each test tube.
And finally into test tube 3, I pipetted 1.0 ml turnip extract and 4.0 ml of water. The contents of test tube 1 was poured into a spectrometer tube and labeled it “B” for blank. “B” tube was now inserted it into the spectrometer. An adjustment to the control knob was made to zero the absorbance reading on the spectrometer since one cannot continue the experiment if the spectrometer is not zeroed. A combination of two people and a stop watch was now needed to not only record the time of the reaction, but to mix the reagents in a precise and accurate manner. As my partner recorded the time, I quickly poured tube 3 into tube 2. I then poured tube 2 into the experiment spectrometer tube labeled “E” and inserted it into the spectrometer. A partner then recorded the absorbance reading for every 20 seconds for a total of 120 seconds. After the experiment, a brown color in the tube should be observed to indicate the reaction was carried out. Using sterile techniques, any excess liquid left was disposed
The purpose of this experiment is to determine the maximum absorbance of fast green, and the chlorophylls, also in the case of fast green create a concentration curve to determine an unknown substance. Each test will use the spectrophotometer.
The procedures for experiment A, B, and C all start the same. The first step is to put on goggles and get the data collection device set properly. The labquest needs to be plugged into the colorimeter accurately so that a click is heard when putting it in. The labquest needs to be reading digitally and the colorimeter needs to be set to 635 nm. Then shake the chloroplast solution and take a clean cuvette and fill it with 3 mL of distilled water, 3 drops of the chloroplast solution, and cap it. This is used as a blank to calibrate your labquest. Double check that the labquest is reading absorbance, this assures that the colorimeter is plugged into the labquest accurately. Insert the blank into the colorimeter and hit the calibration button. Take out the blank and empty it. The labquest is now set to experiment with. Make sure that the heat bank is set in front of the lamp and that the lamp is on. The cuvette must be placed on the opposite side of the heat bank in the path of light in the box so that no other light can interfere with the experiment.
The purpose of this lab is to observe the effect of white, green, and dark light on a photosynthetic plant using a volumeter and followed by the calculation of the net oxygen production using different wavelengths color of white and green light, and also the calculation of oxygen consumption under a dark environment, and finally the calculation of the gross oxygen production.
Using the brush collect sample and put the brush in the specimen adding the brush to the sample prep and snap of the break mark and close the cap. Vortexes the sample prep for 10 seconds then remove the cap frim the heat treatment tube. Remove the dropper cap from the sample prep and squeeze 5-10 drops of the sample into the heat treatment at 95oC for 10 minutes. After remove each treatment tube and vortex for 10 seconds. Use the calibrated pipette transfer 50 microlitres from the heat mixture sample into reaction buffer tube. Replace the cap of and remove 1 test device for each sample to be tested. Open the device by pulling up and back on the large tap. Use a pipette transfer 50 microliters of the heat treated sample into the first chamber of the test device and close the cap. Check all test devices looking for any air bubbles present. Then start the amplification reaction and detection and press start. After 40 minutes result is shown if positive, it means Clostridium difficile is present.
Incorporation of assay controls included setting up a spectrophotomer and running the chart recorder with a full-scale deflection before the start of the assay. The set recorder had a corresponding value of 1 for the change in the absorbance. Therefore, prior testing was done to observe whether a change occurred in the readings. This helped to indicate that the results were valid, as they could have been affected by a fault during the setting up of the spectrophotometer. On the other hand this was considered as one of the controls for the experiment. Nevertheless, a new cuvette had to be used for each assay.
photosynthesis happens in two stages: light reaction and carbon fixation also known as calvin cycle.light reaction TAKES PLACE IN THYLAKOID USE light energy to produces atp and nadph whereas, calvin cycle takes place instroma uses energy derived from light dependent reaction to make GA3P from CO2 ( Bio166 lab execise manual, 2015). the purpose of this experiment was to separate plant
This experiment focus on pigments quantification from chloroplast. Pigments are extracted from frozen chloroplasts extracted from barley leaves. Dilution was made using buffer. In order to get final concentration acetone (100%) was added into each dilution. Thereafter total concentration of pigments is determined
A chloroplast working solution had already been prepared by the lab professor. Seven different glass test tubes were set up and each tube was labeled with numbers 1 to 7. 4ml of the chloroplast working solution were put in each tube along with 3 drops of DCPIP in tubes labeled from 2 to 6. The contents were mixed by inverting the tubes twice. The glass tubes were placed inside colored plastic centrifuge tube (the colors for each tube were indicated in the table) and sealed with a black cap at the end. Forthwith, the test tube racks were placed under sunlight and a stopwatch was set up. All the test tubes were supposed to be brought back to the lab after the reaction in test tube complete i.e. when the color of test tube 2 changed to match the
To do so, we used the cuvette 0, also known as the blank, and the cuvette 5, the pure substance. We calibrated our spectrophotometer by setting the λ (wavelength) to 383 nm and then placing the blank in. Afterwards, we set the transmittance to 100%. Then, we removed the blank cuvette and placed the cuvette 5 in. After recording the %T and absorbance, we repeated the process but with a different wavelength. We repeated with wavelengths ranging from 383 to 700, recording the %T and absorbance each time.
C 1mL of complex stock solution was added and quickly mixed. Time was measured until the colour of the test tubes matched. This was repeated by intervals of 4-5°C up until 62.6°C
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.
The following procedure dealt with a chromatogram. The materials needed are: a pencil, safety goggles, scissors, chromatography paper strip, capillary tube, spinach plant pigment extract, test tube, cork stopper, graduated cylinder, chromatography solvent (alternative isopropyl alcohol), metric ruler, stopwatch or clock with a secondhand, hook/fashioned paperclip, paper towels, test tube rack, and mortar and pestle. First we obtained a strip of chromatography paper and cut it so it would fit inside a test tube (with it barely touching the bottom of the tube). Also, when touching the strip, touch the sides only. Then we attached (firmly) the top of the strip to a hook (or fashioned paperclip at bottom of the cork stopper). Make sure it fits in the test tube. Next we used the pencil to draw a faint line across the strip two centimeters from the bottom tip of the strip. We placed the cork and strip in place, and we put a mark on the test tube one centimeter below the top of the stopper.
(This experiment is aimed to use 10 Artemia, however, 7 to 13 Artemias are able to achieve the goal in this experiment.). Then seal the cuvette under water and make sure no air bubble is inside the cuvette. After that, put the cuvette into the temperature controlled water bath for ten minutes. After 10 minutes, take the cuvette to the oxygen meter to measure the oxygen concentration by holding the end of the end of the fibre-optic cable squarely on to the senor spot from the outside of the cuvette until the concentration has been shown on screen and record it down. Then return the Artemia to the same incubation bath and repeat this procedure every 5 minutes and measure it for 4 to 5 times. After the process above, we have to find out the total length of the Artemias in the cuvette. To find the total length of the Artemia, use the pipette to move the Artemia out of the cuvette and settle them into a watch glass and measure the length of the Artemias by ruler. At last but not least, put those high energy intake Artemia back into the sink and repeat the experiment instead of those low intake Artemia. On the other hand, to find the difference of activity of the high and low energy intake Artemia, those Artemia will be tracked by the software named, the Tracker and the Tracker are able to determine the velocity of the Artemia under different treatment for 5 replicates.