StudyMoose App
24/7 writing help on your phone
Save to my list
Remove from my list
The absorbance of light is a key factor of photosynthesis because light is a necessary reactant for photosynthesis, however temperature can affect how much light is able to be absorbed. Organisms have a set range of temperature that they are able to function best in, when the temperature changes in an organism’s area to be outside of their range, the organisms will adapt or expend their energy (Cain etal, 2016). This effects photosynthesis because the changes in photosynthetic rate in response to temperature are reversible over a considerable range, however if exposed to a temperature outside of this range, the photosynthetic system may develop an injury that cannot be reversed (Berry and Bjorkman, 1980).
4.9 (247)
“ Rhizman is absolutely amazing at what he does . I highly recommend him if you need an assignment done ”
This means that photosynthesis is affected by temperature because of temperatures role in photosynthesis that comes from the dependence of temperature in relation to the integrity of the apparatus remaining intact and temperatures effect on the inhibitance of photosynthesis due to the integrity being disrupted by changes in temperature (Berry and Bjorkman, 1980). It was hypothesized that at a higher temperature, the amount of carbon dioxide being produced or used would be greater than at a lower temperature. The results showed that more light was absorbed in relationship to time for 30°C then for 25°C. This is because absorbance decreased faster at 25°C meaning that more was able to be absorbed at 30°C. The quicker decrease in absorbance at 25°C is because of how much closer together the absorbance values were at 25°C which meant that it was much quicker to move between those numbers.
Photosynthesis is a process where light energy from the sun is harvested and then stored as sugar (Upadhyaya, 2019). Photosynthesis is an energy transferring system in which autotrophs get energy from the environment and then turn this into a product that can be used by them as well as other organisms like heterotrophs which rely on the energy received from autotrophs (Upadhyaya, 2019). In photosynthesis, the products created by the two phases are both consumed and produced (Upadhyaya, 2019). The equation for photosynthesis is 6CO2 + 6H2O + energy → C6H12O6 + 6O2 (Upadhyaya, 2019). The different phases of photosynthesis are called the light reactions and the Calvin cycle (Upadhyaya, 2019). The light reactions take place within the thylakoids of the chloroplasts for eukaryotes and it is in light reactions where solar energy is converted into chemical energy and water is split to form oxygen (Upadhyaya, 2019). The Calvin cycle takes place in the stroma of the chloroplasts and can occur independent of light (Upadhyaya, 2019).
The Calvin cycle relies on the ATP and NADPH that is produced in the light reactions to be able to convert carbon dioxide into sugars though, meaning it indirectly does rely on sunlight (Upadhyaya, 2019). The Calvin cycle is the home of RuBisCO, the enzyme that is responsible for fixating carbon dioxide (Upadhyaya, 2019). Pigments that are found within the chloroplast are what are responsible for capturing solar energy because they are what absorb the wavelengths of light, different ones absorbing different wavelengths (Upadhyaya, 2019). Different wavelengths can affect how effective photosynthesis is since photosynthesis relies on the absorbance of light (Upadhyaya, 2019).
The question being answered by this experiment was how different temperatures affect the amount of carbon dioxide being produced or used in photosynthesis. It was hypothesized that at a higher temperature, the amount of carbon dioxide being produced or used would be greater than at a lower temperature.
Temperature is one of the physical factors of the Earth’s climate. The patterns of global climate are determined largely by the movement of Earth through space and the solar energy that is being inputted (Cain etal, 2016). The sun’s warming of the atmosphere, land, and water is what establishes the variations in temperature, movement of air as well as water, and dramatic latitudinal variations in the climate that is a result of water being evaporated (Cain etal, 2016). Earth’s axis and rotation around the Sun also create seasonal cycles in temperature (Cain etal, 2016). The temperature drop at night over land is quicker than over water, this causes the rise of warm water which draws cooler air from the land back out over the water and then is replaced by warmer air that comes from offshore (Cain etal, 2016). Also, mountains affect temperature because they affect the amount of sunlight that is able to hit the environment around them (Cain etal, 2016).
An important factor in the distribution of organisms is temperature. This is because of the effect that the distribution of organisms has on biological processes (Cain etal, 2016). Organisms typically function best within a set range of temperature however if the temperature changes in the area they are found in, they will either adapt to live outside of their range or expend their energy (Cain etal, 2016). This can cause a decrease in the number of other organisms because the organisms that have expanded their range might start to eat the other present organisms (Cain etal, 2016).
Photosynthesis is greatly affected by temperature because the changes in photosynthetic rate in response to temperature are reversible over a considerable range, however if exposed to a temperature outside of this range, the photosynthetic system may develop an injury that cannot be reversed (Berry and Bjorkman, 1980). This means that photosynthesis is affected by temperature because of temperatures role in photosynthesis that comes from the dependence of temperature in relation to the integrity of the apparatus remaining intact and temperatures effect on the inhibitance of photosynthesis due to the integrity being disrupted by changes in temperature (Berry and Bjorkman, 1980).
Higher plants that come from habits of contrasting temperature show differences in their photosynthetic response to temperature and also in how they are able to maintain their integrity in different degrees of temperature (Berry and Bjorkman, 1980). This is because of adaptations that may be looked at as a genotypic variation present in key elements of the apparatus of photosynthesis that let plants function in a way under their temperature ranges related to their habitats that lets them reach efficiency (Berry and Bjorkman, 1980). Also, some plants have considerable phenotypic plasticity that is present in their characteristics that are known as photosynthetic (Berry and Bjorkman, 1980). This means that genotype growth under a cool regime will result in the capacity of photosynthesis at lower temperatures to be improved and genotype growth under a warm regime to result in the performance of photosynthesis at higher temperatures to be improved (Berry and Bjorkman, 1980).
Like photosynthesis, temperature also plays a role in cellular respiration. Temperature’s effect on respiration rate is very influential as it is considered to be the most influential external factor when it comes to respiration rate, this is because respiration decreases as temperature also decreases (Lyons and Breidenbach, 1990).
The organism used in this experiment was S. obliquus which is an algae species that is found in freshwater. S. obliquus is a freshwater colonial non-motile alga that is under the Scenedesmus genus (Upadhyaya, 2019). S. obliquus has been determined as a microalga that could be promising when it comes to the large-scale production of lipids because it showed that it has a high biomass production that has resulted in the high productivity of lipids and fatty acids (Haneltetal, 2013).
In this experiment, we investigated the rate of light absorbed by S. obliquus in photosynthesis in relation to temperature and the elapse of time. Through the use of a spectrophotometer, we were able to find the amount absorbed over 30 minutes for S. obliquus at 25°C and 30°C, which showed that the light was absorbed more in relationship to time for 30°C than for 25°C. The ability to use the spectrophotometer to find the absorbance rates also allowed us to be able to use a CO2 colorimetric indicator to determine how much CO2 was being produced or used. Thus, our experiment establishes that S. obliquus absorbs more light at higher temperatures within its range.
Algae strain
Two empty cuvettes had six algae beads added to each cuvette using a pipette, making a total of twelve algae beads. After 6 algae beads were added to each cuvette, a pipette was used to add 2ml of CO2 indicator fluid to each cuvette.
Absorbance Values and Temperature Controls
The amount absorbed was measured using the spectrophotometer at a wavelength of 550. Each cuvette was placed in the spectrophotometer one at a time to find their initial absorbance rates at 0 minutes. After the absorbance rates were measured for both cuvettes, one cuvette was placed into a heat bath that had a temperature set at 30°C and the other cuvette was left out at room temperature which was equivalent to 25°C. At 5-minute intervals for a total of 30 minutes, the cuvette was taken out of the heat bath and its absorbance value was measured as well as the cuvette left out at room temperature, then the cuvette from the hot bath was placed back in the hot bath and the room temperature cuvette was left out of the spectrophotometer.
CO2 Production and pH Values
At 5-minute intervals for a total of 30 minutes, the CO2 colorimetric indicator was used to determine if CO2 was produced based off the color of the indicator fluid in relation to its pH value.
Data Presentation and Analysis
After 30 minutes have passed, the absorbance values in relation to time for both cuvettes were graphed as well as the change in absorbance over time for both cuvettes. For the graph, time was put on the x-axis and absorbance was put on the y-axis. The change in absorbance over time was calculated by subtracting each absorbance value by the initial absorbance value and then dividing by time.
Tables were also used to show the rate of absorbance over time. The table had three columns, one for time measured in minutes, absorbance for 25°C, and absorbance for 30°C. There were 8 rows, one that held the headings and 7 more for the data measured. Another table was used to show pH values over time. The table had three columns, one for time measured in minutes, pH value for 25°C, and pH value for 30°C. There were also 8 rows, one that held the headings and 7 more for the data measured.
The graphs and tables all were numbered, had titles that related to what was being presented, and captions that described what was presented in more detail.
The rate of absorbance over time is often affected by temperature. Graph 1 shows the effect of different temperatures on the rate of absorbance for S. obliquus for 30 minutes of experimenting. The absorbance value at 0 minutes from the cuvette at room temperature or 25°C was 0.004AU higher than the cuvette at 30°C, with the initial rate of absorbance for the cuvette at 25°C being 0.123AU and it being 0.119 for the cuvette at 30°C.
However, the rate of absorbance over time decreased faster for 25°C, going from 0 AU/min, 0.0044 AU/min, 0.0023 AU/min, 0.00233333 AU/min, 0.00215 AU/min, 0.00212 AU/min, 0.00183333 AU/min then for 30°C which went from 0 AU/min, 0.0018 AU/min, 0.0015 AU/min, 0.00186667 AU/min, 0.0018 AU/min, 0.00168 AU/min, then 0.00153333 AU/min, even though the values at 30°C were lower. The results in Table 1 show that although the absorbance values were greater at 25°C then 30°C, the rate of absorbance over time decreases more at 25°C then at 30°C meaning that absorbance is faster at 30°C. The absorbance values at 25°C were 0.123AU at 0 minutes, 0.145AU at 5 minutes, 0.146AU at 10 minutes, 0.158AU at 15 minutes, 0.166AU at 20 minutes, 0.176AU at 25 minutes, and 0.178AU at 30 minutes. The absorbance values at 30°C were 0.119AU at 0 minutes, 0.128AU at 5 minutes, 0.134AU at 10 minutes, 0.147AU at 15 minutes, 0.155AU at 20 minutes, 0.161AU at 25 minutes, and 0.165AU at 30 minutes.
Table 2 shows that the pH values at 25°C were higher than at 30°C meaning that the colors for 25°C are deeper. The pH colors at 25°C were a bright orange with red undertone at 0 minutes, a bright orange with deeper red undertone at 5 minutes, same as 5 minutes at 10 minutes, a bright orange with deep red undertone at 15 minutes, a burnt red with orange undertone at 20 minutes, a burnt red with slight orange undertone at 25 minutes, and a burnt red at 30 minutes. The pH colors at 30°C were a bright orange with slight red undertone at 0 minutes, a bright orange with red undertone at 5 minutes, a bright orange with deeper red undertone at 10 minutes, a bright orange with deeper red undertone at 15 minutes, a bright orange with deep red undertone at 20 minutes, a burnt red with orange undertone at 25 minutes, and a burnt orange with less orange undertone at 30 minutes. The pH values at 25°C were ≈8.2 from 0 minutes till 15 minutes, ≈8.2-8.3 at 20 minutes, ≈8.3 at 25 minutes, and 8.3 at 30 minutes. The pH values at 30°C were ≈8.2 from 0 minutes till 20 minutes and ≈8.2-8.3 from 25 minutes till 30 minutes.
The obtained results suggested that photosynthesis occurred since nutrients are created by photosynthesis when light is absorbed. The absorbance values increasing from 0.123AU to 0.178AU at 25°C and from 0.119AU to 0.165AU at 30°C verifies that photosynthesis is occurring since more light is being absorbed which results in the creation of nutrients. These results also suggest that the pH value is increasing since pH can be found from absorbance values.
The absorbance values increasing from 0.123AU to 0.178AU at 25°C verify this since 0.123AU can be correlated to a pH value of ≈8.2 and 0.178AU correlates to a pH value of 8.3. The absorbance values increasing from 0.119AU to 0.165AU at 30°C also verify this 0.119 can be correlated to a pH value of ≈8.2 and 0.165AU can be correlated to a pH value of ≈8.2-8.3. These results also suggest that the pH value is increasing based on the deepening of the CO2 indicator color. The CO2 indicator color started as a bright orange with red undertones at an absorbance of 0.123AU for 25°C which correlates to a pH of ≈8.2 and turned to a burnt red at an absorbance of 0.178AU which correlates to a pH of 8.3. The CO2 indicator color started as a bright orange with slight red undertone at an absorbance of 0.119AU for 30°C which correlates to a pH of ≈8.2 and turned to a burnt red with orange undertone at an absorbance of 0.165 which correlates to a pH of ≈8.2-8.3. The deepening of the CO2 indicator color also correlates to an increase in absorbance value which can be verified by the results.
The obtained results suggest that cellular respiration did not occur since CO2 is being used and not produced, meaning photosynthesis is dominant. The absorbance values increasing from 0.123AU to 0.178AU at 25°C and from 0.119AU to 0.165AU at 30°C verifies that cellular respiration is not occurring since absorbance values decrease during cellular respiration. The initial absorbance value of 0.123AU correlating to a pH of ≈8.2 and final absorbance value of 0.178 correlating to a pH of 8.3 at 25°C verifies that cellular respiration is not occurring since pH values decrease during cellular respiration because of pH values relation to absorbance values.
The initial absorbance value of 0.119 correlating to a pH of ≈8.2 and final absorbance value of 0.165 correlating to a pH of ≈8.2-8.3 at 30°C also verifies that cellular respiration is not occurring since pH values decrease during cellular respiration because of pH values relation to absorbance values. The CO2 indicator color starting as a bright orange with red undertones at an absorbance of 0.123AU for 25°C which correlates to a pH of ≈8.2 and turning to a burnt red at an absorbance of 0.178AU which correlates to a pH of 8.3 verifies that cellular respiration is not occurring since CO2 indicator color lightens during cellular respiration because of the relationship between pH values, absorbance values, and CO2 indicator color. The CO2 indicator color starting as a bright orange with slight red undertones at an absorbance of 0.119AU for 30°C which correlates to a pH of ≈8.2 and turning to a burnt red with orange undertones at an absorbance of 0.165AU which correlates to a pH of ≈8.2-8.3 also verifies that cellular respiration is not occurring since CO2 indicator color lightens during cellular respiration because of the relationship between pH values, absorbance values, and CO2 indicator color.
It was hypothesized that at a higher temperature, the amount of carbon dioxide being produced or used would be greater than at a lower temperature. The obtained results suggest that the amount of CO2 being used during photosynthesis decreases, meaning that an increase an absorbance correlates to a decrease in CO2. The absorbance values were higher at 25°C but the change in absorbance over time was slower at 30°C. The change in absorbance being slower at 30°C means that more will be able to be absorbed over time at 30°C. This means that CO2 will be able to decrease even more at 30°C over time because the change in absorbance over time will continue to decrease for longer.
The results show that carbon dioxide is used more at higher temperatures within an organism’s range but will be lower outside of that organism’s range. This means the climate change will continue to have a negative impact because organism’s will continue to work outside of their temperature range at higher temperatures meaning that there will continue to be a decrease in the amount of CO2 being used.
The absorbance value at 0 minutes for both temperatures were not zero because time passed between when the cuvettes had everything added to them and when the spectrophotometer was used to measure the absorbance for both cuvettes. If the experiment was redone, the amount of time between events would be reduced even more to make sure the absorbance values were as close to 0 as possible.
The results of this experiment have led to questions about what would happen at extreme values of heat and what would happen at extreme values of cold. If this topic was looked into further, additional cuvettes would be added that would be under higher temperatures and cooler temperatures then room temperature.
Temperature Effects on Photosynthesis: Absorbance Dynamics in S. obliquus. (2024, Feb 22). Retrieved from https://studymoose.com/document/temperature-effects-on-photosynthesis-absorbance-dynamics-in-s-obliquus
👋 Hi! I’m your smart assistant Amy!
Don’t know where to start? Type your requirements and I’ll connect you to an academic expert within 3 minutes.
get help with your assignment
