I B personal ID: lhy488
Word count: 2984
hat is the effect of UV light concentration (measured by distance from uv lamp: 0cm, 10cm,
W
20cm, 30cm, 40cm) on the photosynthetic process in algae (microcystis) in terms of change in
the pH levels after a total of 1 hour when UV is concentrated for 10 minutes?
1. Introduction
Photosynthesis is the process by which a plant is able to transform light into chemical
energy. The general formula for photosynthesis is: 6CO2 + 6H2O → C6H
12O6
+ 6O2 and it allows
for plants to take in CO2 which can have a significantimpact on the pH levels. Aquatic plants can
be studied in order to understand how the process of photosynthesis can impact other important
factors such as the ocean. Algae is an organism that is found almost everywhere in the ocean and
the species Chrysophyta and microcystis are the most abundant and common algae found in the
ocean. However, microcystis is the most redundant species of algae in Malaysia and therefore, it
can be used to gain generalized understanding on how different species of algae would react
when exposed to UV rays.
Nonetheless, as the plants photosynthesize, they are able to absorb the CO2 which
increases the pH into alkaline levels that can be harmful for living organisms (since it is not
optimal pH). An excessive amount of CO2 will allowfor the oxygen atom from the water
molecule (H2O) to be attracted to the carbon fromcarbon dioxide (CO2), therefore causing the
formation of carbonic acid (ACS). This carbonic acid is what allows for the acidification of the
water, and therefore lowers the pH.
Microcystis (algae) is important to have in ecosystems however an excessive amount can
be detrimental to any aquatic ecosystem whether that is freshwater or saltwater. Yet the impacts
of UV exposure on algae in these aquatic environments has not been studied in order to
comprehend the relationship. According to researchers, algae cell structure can be damaged due
to over-exposure to UV light (Tekiner et al.). However the impact on their photosynthetic
process has not yet been measured. This is what will be explored in this IA to fully investigate
the relationship between the photosynthetic process in algae and the exposure of UV.
2.1: Variables
I ndependent variable:UV light concentration (changedby distance from UV lamp: 0cm,
10cm, 20cm, 30cm, 40cm)
ependent variable:Change in the photosynthetic process(measured by the recognizing the
D
change in pH)
Controlled variables:
The volume of water will remain constant throughout the experiment at 50mL. This
value will be measured using a beaker (+/- 0.1). Changes in the volume of water can lead to
differences in the pH as there will be different ratios of water to algae, furthermore causing
fluctuations in the results. It creates different concentrations of dissolved carbon dioxide which
is directly proportional to changes in pH (Fondriest Environmental).
, he mass of algae will remain constant at 2g per piece (25 pieces total). This value will be
T
measured using the same electronic balance (+/- 0.05) as well. Keeping the mass of the algae
will allow for an accurate comparison of the effects of the exposure of UV light at different
concentrations. If this was not a constant, then the data would be inaccurate due to the fact that
greater amounts of algae will be able to photosynthesize ‘more’ compared to smaller amounts.
The duration of UV light exposure will stay constant at 10 minutes for every trial and its
replicates, and will be measured with a timer (+/- o.01). Inconsistent exposure can lead to
inaccuracy in the data due to the impacts on the process of photosynthesis.
The pH monitor will be calibrated before each reading to ensure there are no fluctuations
due to residue of the previous solution’s pH impacting the readings. Without this, the data may
have been inaccurate.
The lamp that is used to provide light to the algae after the UV light exposure will remain
constant with a 110-240V and 7 wattage. Using the same lamp ensures that the exact same
intensity of light is given to each replicate and each trial. Keeping the conditions constant will
provide the most accuracy in the outcome of the data.
Justification:
The variables were specifically chosen to understand the relationship between the
intensity of UV light an aquatic plant gets and the pH levels. However the independent variable
specifically in terms of the distances were selected in order to determine with a sufficient
difference in exposure concentrations to the UV light. When completing the pre-trials these
distances showed a distinct difference in pH levels indicating a difference in exposure. There is
no way to measure the actual UV rays that were received by the algae at different distances
without devices such as UV ray meters (that were not available at my school).
3.1: Methodology
1. O btain 25 pieces of algae (microcystis) that weigh 2g each from a pond or beaker where
they were cultured
2. Add 50 ml of water to all 5 test tubes (5 test tubes due to replicates)
3. Place one piece of algae (2g) into each test tube
4. Calibrate the pH monitor with pH buffer 4 and 7 before collecting any data
5. Measure the initial pH of each test tube with the pH monitor
6. Close the test tube with a rubber cap to ensure no external particles can impact the final
pH calculated later
7. Due to safety precautions: find a closed off cabinet where no UV rays can be exposed and
use that to place the test tubes and always wear UV light glasses to protect the eyes from
the UV ray exposure
8. Measure a distance of 0 cm from the UV lamp (0 cm away) and place the test tube in that
closed off cabinet
9. Let the test tube with algae sit under the UV lamp for 1o minutes
10.Remove the test tube from the UV lamp and place under a 210V lamp to let
photosynthesize as per usual (50 min)
11. After a total of 60 minutes, measure the new pH with the pH monitor
12. Repeat steps 2 through 11 to complete the data for the other distances : 10cm, 20cm,
30cm, 40cm)
Word count: 2984
hat is the effect of UV light concentration (measured by distance from uv lamp: 0cm, 10cm,
W
20cm, 30cm, 40cm) on the photosynthetic process in algae (microcystis) in terms of change in
the pH levels after a total of 1 hour when UV is concentrated for 10 minutes?
1. Introduction
Photosynthesis is the process by which a plant is able to transform light into chemical
energy. The general formula for photosynthesis is: 6CO2 + 6H2O → C6H
12O6
+ 6O2 and it allows
for plants to take in CO2 which can have a significantimpact on the pH levels. Aquatic plants can
be studied in order to understand how the process of photosynthesis can impact other important
factors such as the ocean. Algae is an organism that is found almost everywhere in the ocean and
the species Chrysophyta and microcystis are the most abundant and common algae found in the
ocean. However, microcystis is the most redundant species of algae in Malaysia and therefore, it
can be used to gain generalized understanding on how different species of algae would react
when exposed to UV rays.
Nonetheless, as the plants photosynthesize, they are able to absorb the CO2 which
increases the pH into alkaline levels that can be harmful for living organisms (since it is not
optimal pH). An excessive amount of CO2 will allowfor the oxygen atom from the water
molecule (H2O) to be attracted to the carbon fromcarbon dioxide (CO2), therefore causing the
formation of carbonic acid (ACS). This carbonic acid is what allows for the acidification of the
water, and therefore lowers the pH.
Microcystis (algae) is important to have in ecosystems however an excessive amount can
be detrimental to any aquatic ecosystem whether that is freshwater or saltwater. Yet the impacts
of UV exposure on algae in these aquatic environments has not been studied in order to
comprehend the relationship. According to researchers, algae cell structure can be damaged due
to over-exposure to UV light (Tekiner et al.). However the impact on their photosynthetic
process has not yet been measured. This is what will be explored in this IA to fully investigate
the relationship between the photosynthetic process in algae and the exposure of UV.
2.1: Variables
I ndependent variable:UV light concentration (changedby distance from UV lamp: 0cm,
10cm, 20cm, 30cm, 40cm)
ependent variable:Change in the photosynthetic process(measured by the recognizing the
D
change in pH)
Controlled variables:
The volume of water will remain constant throughout the experiment at 50mL. This
value will be measured using a beaker (+/- 0.1). Changes in the volume of water can lead to
differences in the pH as there will be different ratios of water to algae, furthermore causing
fluctuations in the results. It creates different concentrations of dissolved carbon dioxide which
is directly proportional to changes in pH (Fondriest Environmental).
, he mass of algae will remain constant at 2g per piece (25 pieces total). This value will be
T
measured using the same electronic balance (+/- 0.05) as well. Keeping the mass of the algae
will allow for an accurate comparison of the effects of the exposure of UV light at different
concentrations. If this was not a constant, then the data would be inaccurate due to the fact that
greater amounts of algae will be able to photosynthesize ‘more’ compared to smaller amounts.
The duration of UV light exposure will stay constant at 10 minutes for every trial and its
replicates, and will be measured with a timer (+/- o.01). Inconsistent exposure can lead to
inaccuracy in the data due to the impacts on the process of photosynthesis.
The pH monitor will be calibrated before each reading to ensure there are no fluctuations
due to residue of the previous solution’s pH impacting the readings. Without this, the data may
have been inaccurate.
The lamp that is used to provide light to the algae after the UV light exposure will remain
constant with a 110-240V and 7 wattage. Using the same lamp ensures that the exact same
intensity of light is given to each replicate and each trial. Keeping the conditions constant will
provide the most accuracy in the outcome of the data.
Justification:
The variables were specifically chosen to understand the relationship between the
intensity of UV light an aquatic plant gets and the pH levels. However the independent variable
specifically in terms of the distances were selected in order to determine with a sufficient
difference in exposure concentrations to the UV light. When completing the pre-trials these
distances showed a distinct difference in pH levels indicating a difference in exposure. There is
no way to measure the actual UV rays that were received by the algae at different distances
without devices such as UV ray meters (that were not available at my school).
3.1: Methodology
1. O btain 25 pieces of algae (microcystis) that weigh 2g each from a pond or beaker where
they were cultured
2. Add 50 ml of water to all 5 test tubes (5 test tubes due to replicates)
3. Place one piece of algae (2g) into each test tube
4. Calibrate the pH monitor with pH buffer 4 and 7 before collecting any data
5. Measure the initial pH of each test tube with the pH monitor
6. Close the test tube with a rubber cap to ensure no external particles can impact the final
pH calculated later
7. Due to safety precautions: find a closed off cabinet where no UV rays can be exposed and
use that to place the test tubes and always wear UV light glasses to protect the eyes from
the UV ray exposure
8. Measure a distance of 0 cm from the UV lamp (0 cm away) and place the test tube in that
closed off cabinet
9. Let the test tube with algae sit under the UV lamp for 1o minutes
10.Remove the test tube from the UV lamp and place under a 210V lamp to let
photosynthesize as per usual (50 min)
11. After a total of 60 minutes, measure the new pH with the pH monitor
12. Repeat steps 2 through 11 to complete the data for the other distances : 10cm, 20cm,
30cm, 40cm)
