Spinach Chloroplast Lab Report

Without the SDH enzymes found in the inner mitochondrial membrane the DCIP does not get reduced, therefore there is no color change in the solution. The dependent variable of this experiment was the change in absorbance at 600 nm, as the differing number of mitochondria in the cell fractions is what causes the change in absorbance. The independent variable was the number of mitochondria in the cell fractions, as the mitochondria levels were manipulated, the values of reduction of DCIP varied. The control was the solution E1 (None), which contained no cauliflower cell fraction. This provided data that guaranteed a solution without any mitochondria present, that tubes E2-E4 could be compared to.

The initial experiment was a success. As our treatment group spent more and more time under the lights, the absorbance rate continues to decrease toward zero. Once our 30 minutes were up, the absorbance rate in each tube was significantly lower than at the start of our experiment. In contrast the two control groups did significantly lower the absorbance. Each control lacked one of the vital aspects of photosynthesis, one being light, and the other being chloroplast. Neither of the control groups (Control 1 or 2) showed any signs of photosynthesis. Control 1 was exposed to light, but contained no photosynthetic organelles thus the absorbance throughout the 30 minutes varied minimally, mostly staying stagnant. Control two which contained chloroplast but was not exposed to any light failed to lower the absorbance at all and in fact increased the absorbance over the 30 minutes. However, the treatment group contained both and ultimately performed photosynthesis as we expect therefore, confirming our assumption that chloroplast were the organelles required for photosynthesis in plants and that light is required to perform said photosynthesis. The treatment group, containing both the chloroplast and being exposed to light provided evidence that photosynthesis was taking place as the absorbance lowered at each 10-minute interval. Having a less absorbance would be desired because as DCIP became reduced we would expect the solution to become more and more clear, thus less

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.

The organism studied in these experiments was the Spinacia oleracea that was obtained from a local grocery store in Lincoln Nebraska. One experiment that was conducted was used to determine the rate of oxygen production of Spinacia oleracea in the dark. Another experiment conducted was used to determine the effect of light intensity on the net photosynthetic rate of a Spinacia oleracea. The effect of light wavelength on the net photosynthetic rate of a Spinacia oleracea was also conducted and observed. The last experiment conducted was conducted to identify the pigments in Spinacia oleracea in order to determine its chloroplast chromatography.

Enzymes are able to catalyse due to their globular structure which has a region on their surface that has a specific shape. This shape is complementary to the shape of the reactant or reactants of the reaction that the enzyme will catalyse. This region on the enzyme is referred to as the active site which binds to the substrate in order for the reaction to occur.

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

In the beginning of this experiment, our TA added water, salt, and 75/25 hexane/acetone to spinach leaves to a blender and blended the mixture to assume equal amounts for each group and to avoid erros if each student had to do the blending. The addition of the water to the mixture allowed the it to separate into a distinct organic layer after being run in a centrifuge, which was available to be collected at the top of the centrifuge. Salt reduces solubility, which will force the organic parts of the mixture (the desired pigments for example) to separate into the organic layer at the top. Lastly, 75/25 hexane/acetone is added because this is a moderately polar solvent and will useful for both the non-polar and polar pigments present within the spinach leaves. A mixed solution of hexanes and acetone must be used because acetone is very polar, while hexane in very non-polar, and the spinach leaves contain both non-polar and polar pigments in them that are important in the extraction and for further analysis. The mixture was placed in the centrifuge so the solids in the mixture (mostly cellulose) could be separated from the liquids into separate distinct layers for further extraction and testing. In the tube, the organic substances separated into the top layer, whereas the water layer remains at the bottom of the tube below the solid layer made up of mainly cellulose.

For this experiment, my group had several leaves of spinach and hole punched 40 disks out of the spinach leaf. In order to avoid any bias results, we made sure to avoid hole punching any veins in the spinach. After that we filled 4 cups each with 100 milliliters of carbon water. Each cup would have a different amount of salinity, the first cup would be the control group which would have no salt in it. The second cup would have ¼ of a teaspoon of salt in it, the third cup would have ½ of a teaspoon of salt in it, and the fourth cup would have ¾ of a teaspoon of salt in it.

This experiment was performed using the procedure from the Photosynthesis in Leaf Disks Lab. First using a #3

Chloroplast Activity in Cells Questions & Hypothesis In wet lab two, our group decided to use the cells of broccoli to perform our experiments. Part one of our experiment was meant to focus on the presence of chloroplasts in solutions of isolation buffer and DCIP. Our group was attempting to find which cell fractionate solution contained the highest amount of broccoli chloroplasts after three separate suspensions were made (P1, P2, S2). The presence of chloroplasts in the solution is directly related to a decrease in measured absorption of 600 nm wavelengths by a spectrometer (Leicht and McAllister 85).

During this lab, spectroscopy and chromatography was used to determine the various properties and characteristics of fast green solution, chloroplasts and an unknown solution. The spectrometer helped determine the absorbance levels of each substance which was used in this experiment. The levels which were determined were used to find the concentration curve of the concentrated solution of fast green solution and the concentration of the given unknown 215. The chlorophyll solution presented a varied distribution in the absorbance levels which would eventually help us determine what wavelengths are absorbed by chlorophyll. Chromatography was used to separate the components of the chlorophyll (spinach) solution which revealed

If a red light is shown on the leaves, then the rate of photosynthesis will decrease. The experiment conducted shows that red light is not efficient for photosynthesis. When the discs were placed in front of the red light, the discs floated on a much slower pace than the discs in the white light. The hypothesis was correct; the discs floated much slower in the red light. This is probably because the red light appears much dimmer than the white light. Since the leaf needs light for photosynthesis, the light that is dimmer will work less efficiently.

The purpose of this lab was to observe the rate of photosynthesis under different light conditions. Small circles were hole punched out of the spinach leaves. Then a 0.2% solution of sodium bicarbonate was prepared. There were three cups with the solution along with ten leaf disks per cup. The cups were exposed to light for an hour and the number of floating disk was recorded.

In this experiment, the process of chromatography was taken place in order to identify the different types of pigments present in spinach leaf. This was done by carrying out two types of experiments which are thin layer chromatography (TLC) and paper chromatography. Both of the experiments were done using a similar procedure except that they both used a different stationary phase. Paper chromatography used paper, whilst, TLC used a silica plate. Propanone was used as the extraction solvent for spinach leaves and chromatography solvent was used as the mobile phase in the experiment.

The purpose of this experiment was to take spinach leaves and extract the chlorophyll and carotenoid pigments by using acetone as the solvent. The chlorophyll and carotenoid pigments were extracted by using column chromography and alumina was used as the solvent. Solvents of different polarities were used, starting with the least polar, to extract the certain components from the leaves. They were then analyzed by using thin- layer chromatography.