Photosynthesis Lab Report

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 lab is to determine the relationship between photosynthesis and cellular respiration.The effect of Light Intensity experiment will show the rate of photosynthesis based on the amount of light from the light bulb, temperature, and direction and distance of the light, these variables determine the absorbance. In the effect of Light Wavelength experiment, photosynthesis is affected by different light colors. Photosynthesis in this experiment is more successful with certain colors due to different pigments in chloroplasts only absorbs certain wavelengths. The rate of photosynthesis will be estimating oxygen production in spinach leaf using floating leaf disk procedure. The more floating disks, the more oxygen being produces

Starting off the experiment, we turned on the spectrophotometer and set it to 605 nm. We created our chloroplast solutions using one solution with iceberg lettuce, one with spinach and one with kale. To create the solutions we started out by deveining the iceberg lettuce and placing it under a lamp. Then we put it in a chilled blender, added 0.5 M of chilled sucrose, and put it into the blender. After placing the lid on the blender, we blended the solution in three 10-second bursts.

Parafilm was used to avoid spillage of the solutions in the test tubes. Test tubes were gently inverted every two minutes to create a well-mixed solution because the chelating agents eventually settled. xi. After 10 minutes the catechol was added to test tubes 1-4 and the blank tube was used to calibrate the spectrophotometer. Test tubes were read one after the other after the blank tube, and the transmittance of light was measured and recorded in a

Once the spectrophotometer was set to the appropriate wavelength, distilled water was added to a cuvette that had been cleaned and any oil or fingerprints were removed. This was used to “zero” out the spectrophotometer. After doing so, five test tubes were taken and to each 1mL of phosphate buffer, 3mL of distilled water, and lastly 1mL of 0.01% DPIP was added. The contents in each were mixed until a homogeneous solution was present.

Describe the sequence of events following the absorption of photon of light by reaction-center pigment in photosystem II. Describe the comparable events in photosystem I. How are the photosystems linked together? They are linked together by the electron transport system where the electron will be passed on from the primary electron acceptor (from chlorophyll a or P68)) of PSII to the chain to the chlorophyll a (P700) of PSI.

This begins the process of light dependent reactions. When chlorophyll absorbs that photon an electron gets excited, since it is done by a photon it is called photoexcitation. This chlorophyll is part of a complicated complex pf different molecules, proteins and lipids that is Photosystem II. Photosystem II is the first of four protein complexes that are in the light dependent reactions. Now that electron that was excited by that photon will go on a journey through the electron transport chain where it will loose the energy that it had by a series of chemical reactions.

After wearing the gloves we obtained a chromatography vial from professor and label it with my and my peer initials. We dried up the chromatography vial in fume hood and added 1 ml of chromatography solvent to the vial. Then we took a chromatography strip and measure it 1.5 cm with ruler from one end of the strip and drew a line with pencil we cut two small pieces below the pencil line to form a pointed end. We applied spinach on the strip using quarter to rub the spinach leaf on the line that we drew on the strip and put it into the chromatography vial and placed that in fume hood. We observed as the solvent was moving up the chromatography strip by capillary action. When the solvent was reached approximately 1 cm from the top of the strip then we removed the cap from the vial. We took out the strip from the vial using forceps and marked up the location of the solvent front because it evaporates quickly. We measure out the distance as well as the pigment in order to find out the rf value. Moreover we compared rf values to the one in reference list in order to identify the

In order to test the acidic pH (5.0) a cocktail containg 20.0ml of disttiled water and 1.0ml of chloroplast suspension were used. Instead of interesting the neutral Ph, 6.0ml 0.2M phosphate buffer (pH 5.0). Each test tube, W, X, Y, Dark, and Room were given the exact parameters as activity I. A set distance was placed of 34cm, 70cm, and 99cm respectively for each letter variable and both positive and trial run. Furthermore, a standardized curve was created with the similar dilution factors of activity II, but 0.2M phosphate buffer (pH= 6.0) was replaced with 0.2M phosphate buffer

In tube 2 a few crystals of sodium dithionite were added and the tube was shaken; this tube was the blank. Sodium dithionite reduced DPIP completely. In tube 4, 0.5 ml of 10 mg/ml chloroplast suspension, 6 ml of DPIP, and 0.5 ml of DCMU stock were added. The blank was used to set 100% transmittance on the Spec20 at 580 nm. The absorbance of the other tubes was found and the time and value were recorded.

Photosynthesis begins when photoreceptors absorb light molecules and transfer the energy to neighboring pigments until it reaches the reaction center. The transfer of energy to neighboring pigments is called resonance energy transfer. The photoreceptor in chloroplasts is chlorophyll and there are two main types: chlorophyll a and chlorophyll b. Chlorophyll a and b absorb different light wavelengths of the spectrum. Light harvesting complexes that contain antennae molecules such as chlorophyll a, chlorophyll b, and accessory pigments all absorb light energy and transfer it between neighboring molecules (resonance energy transfer) until it reaches the reaction center.

This experiment is concerned with identifying photosynthetic pigments found in spinach plants and determining the spectrum of light each absorbs. The questions being posed are which pigment is the most active in absorbing energy and which wavelengths of light it absorbs. By using paper chromatography, different pigments of spinach leaves can be separated. Based on the results, it can be concluded that chlorophyll is the most active pigment and photosynthetic pigments in plants absorb light across the entire visible spectrum. The knowledge gained in this experiment is relevant to understanding how the process of photosynthesis works. A real-world application for this includes the harvesting of clean energy sources, as scientific advances have

Before it can function again, it must be replenished with new electrons. Photosystem II accomplishes this task. As in Photosystem I, light energy activates electrons of the Photosystem II pigments. These pigments transfer the energy of their excited electrons to a special Photosystem II chlorophyll molecule, P680, that absorbs light best in the red region at 680 nanometers. Just as in Photosystem I, energy is transferred among pigment molecules and is then directed to the P680 chlorophyll, where the energy is used to transfer electrons from P680 to its adjoining electron acceptor molecule.

The first experiment was Baseline and for that experiment we needed to get three tubes but one of the tubes were already done so the only thing was left is to do test tube two and three and put it together than put it in the spectrophotometer 20. The hypothesis for this experiment

The purpose of this lab was to identify the requirements and products of the photochemical reactions of photosynthesis by specifically looking at the effects of light intensity, light wavelength, and the activity of photosynthetic pigments. Photosynthesis is amongst the most important biochemical processes on earth because it is how the biosphere gets its chemical energy, which is fixed from solar energy. Photochemical, or light, reactions are light dependent and instantaneous reactions that capture energy and split water molecules to release oxygen. They also activate the electron transport chain. In the first experiment, our hypothesis was that the medium light position, 30 cm away, would have the greatest absorption because it is not too close or too far from the light source for absorption. In the second