Spinach Lab Report

Have you ever really wondered how different variables can affect how plants go through photosynthesis? Well, in this experiment, the purpose was to see how various environmental conditions can affect the overall photosynthetic capacity of a specific plant. The factors, light, darkness, cold, and heat were applied to see how the different components would affect the photosynthesis on spinach plants. Each group was given a different factor to test. Out group was given the light factor. The hypothesis for this experiment is that when adding light as a factor, the light will affect the overall plant photosynthesis.

My lab partners and I performed an experiment that involved placing spinach disks into separate cups of distilled water (dH2O) and 0.2% sodium bicarbonate (NaHCO3) solution to examine photosynthesis in leaf tissue (Department of EEB, 2015). Discovering that the spinach disks quickly floated to the top of the 0.2% NaHCO3 solution and not in dH2O, we wondered if varied concentrations of carbonation would affect the rate of photosynthesis (PS). We tested this by halving the 0.2% NaHCO3 solution (using equal parts dH2O and 0.2% NaHCO3 solution to make 0.1% NaHCO3 solution). I hypothesize that if the spinach disks are placed in the 0.1% NaHCO3 solution, then they will have a slower PS compared to the disks placed in 0.2% NaHCO3. CO2

Make sure to use the same type of cuvette to keep the width consistent and to prevent any experimental error from arising. Obtain 5 of the same type of cuvettes and pre-rinse them thoroughly. Label them numbers one through five in increasing molarity. Then, fill each of the cuvettes with one of the five solutions you created back in Part A. We will first examine the solution that exhibits the highest concentration or molarity. Make sure to wipe the outside of the cuvette with a Kimwipe before placing into the SpectroVis Plus device. Observe the graph that is generated and make sure to take note where the maximum absorbance takes place.

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.

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

To check the absorbencies at different wavelengths, we first placed the blank cuvette into the spectrophotometer and set the absorbance to zero. Control cuvettes had to be covered by aluminum to prevent them from light exposure. We then placed all the cuvettes into the ice bath

Each solution contained different concentrations as follows: 0.005 mg/mL, 0.010 mg/mL, 0.015 mg/mL, 0.020 mg/mL, and 0.025 mg/mL. Each solution needed to have a volume of 10 mL. Before adding the different concentrations of Coomassie Blue into their separate tubes, the formula C1V1= C2V2 was used in order to determine how much stock solution is needed for the five dilute solutions. Once that number was calculated, a pipette was used to add the amount of stock solution needed for each tube. We then subtracted the amount of stock solution from 10 mL to determine the amount of H2O needed. The calculated amount of H2O was then added to each tube of solution. After doing that, a spectrophotometer was used to determine each solution’s relative absorbance. However, before that, we first had to calibrate the spectrophotometer before determining each solution’s relative absorbance. In order to calibrate the spectrophotometer, a disposable culture tube filled with distilled water was used. We then changed the data rate to 100 and removed the tube with water. In order to determine the relative absorbance, the relative absorbance had to be at 595 nm. Also, during this experiment, an unknown dilution was given to us by the lab instructor. We determined the relative absorbance by using the spectrophotometer and then recorded the results. The procedures for this experiment can be found on page 8 of

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

Once these steps were completed, the cuvette was placed into the spectrophotometer to test for phosphate, nitrate, ammonia, and turbidity. Inside the spectrophotometer, a light was shot through the sample to detect the contaminant. The first ever spectrophotometer was only developed to calculate pH levels and never used wavelength to calculate the abundance of chemicals within a sample. After many years of developing the spectrophotometer, a glass prism was installed. This allowed the spectrophotometer to use light wavelength to calculate the concentration of chemicals within a sample. The light was able to read the preferred contaminant because a reagent attached to each molecule, and the light was reflected back instead of being shot through the sample. This gave the concentration of each contaminant in the sample. In each machine, there was a different light wavelength programmed to shine through the sample to detect the different contaminants. This was done to get an accurate measurement of phosphate, nitrate, and ammonia within the sample. Turbidity was also measured using the spectrophotometer, but there was no reagent added. The turbidity was calculated by testing distilled water first and comparing it to the turbidity of the BSR water.

Apparatus: Spectrophotometer (UV-1201), cuvettes, water bath (set at 37°C), 200µl and 1000µl micropipettes and test tube

4. The IR spectrophotometer was turned on and set to process the compound. 5. The sample was scanned 16 times then a graph was displayed, depicting absorbance vs. wavenumbers. 6.

This experiment demonstrates the effects of pH on the rate of photosynthesis by examining the behavior of leaf disks in different pH solutions under light. In this experiment, we used five different pH levels: pH 5, pH 6, pH 7, pH 8 and pH 9. These solutions were created using a combination of hydrochloric acid and sodium hydroxide. Spinancia olcerea or spinach, leaves were used in the experiment to examine the effects of pH on the rate of photosynthesis. The rate of photosynthesis was measured by counting the number of leaf disks that rose to the surface of the solution after each minute. In acidic solutions, the rate of photosynthesis increased while in basic solutions, the rate of photosynthesis decreased.

One ml of catechol was added to each of the four new test tubes. The first test tube containing catechol was filled with 4 ml of the pure 5 ml potato extract. Directly after mixing the two together, 1 ml was pipetted into a cuvette and entered into the spectrophotometer. A stop watch would then be set so the wavelength can be recorded at specific times of 30 seconds, 60 seconds, 90 seconds and 120 seconds. These steps would repeat for test tubes two through four.

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.

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