Student Name: Ismael Ogando
Access Code (located on the lid of your lab kit): AC-RLI45E
Lab Report Format Expectations
Utilize college level grammar and professional formatting when completing this worksheet.
Pre-Lab Questions
• Chloroplasts and mitochondria are both unusual in that they have double membranes and
contain their own set of DNA. Can you think of any explanations for this observation?
Because they are developed when prokaryotic cells become absorbed by eukaryotic cells
and those that remain, the resulting cell will have its own DNA and a double membrane.
The structure developed into mitochondria and chloroplasts as new cells were formed.
• Many deciduous trees have leaves that turn yellow in the fall. What do you suppose is
happening in the leaves at the cellular and molecular level?
Chlorophyll production decreases in the fall because to lower temperatures and less
daylight. The primary pigment that predominates during the leaf growth seasons is
usually chlorophyll. Because of the lower temperatures and less light in the fall, the
production gradually slows down and eventually ends. Red, orange, and yellow will now
be reflected as the new color on the leaves because carotenoids, the predominant
pigment in the fall, absorb colors at wavelengths longer than 550 nm.
EXPERIMENT 1: PAPER CHROMATOGRAPHY
Introductory Questions:
• What are you observing in this experiment?
To understand the four components of a chloroplast which are grana, lamella, stroma, and
thylakoids. To describe how the sun impacts all living things using photosynthesis, and then
examine and contrast the reactions that take place during photosynthesis that are dependent on
and independent of light.
• What factors affect the separation of the pigments in paper chromatography?
Based on the chemical structure of the pigments, the solubility, size, and paper-attractiveness of
the particles are the parameters that go into pigment separation.
• What three solutions did you use in this experiment? Why did you use these three different
solutions?
I used sodium bicarbnate, detergent solution and stilled water. Sodium bicarbonate's
purpose provide's a source of carbon dioxide for the plant, detergent solution's purpose
is to help in the bicarbonate solution's penetration into the leaf disks and the distilled
water acts as a comparison control group.
Data and Observations
Table 1: Part 1: Chromatography Data
Solvent
Distance from
Original Line to
Solvent Font
Number of Bands Rf Factor
Acetic Acid 70mm solvent
Pigment 12mm
1 0.171
Acetone 65mm solvent 40mm
Pigment
2 0.615
Mineral Oil 32mm solvent 1cm
pigment
1 0.031
Water 65mm solvent 12mm
pigment
1 0.185
Insert a picture of the four pieces of chromatography paper with your name and access code
handwritten in the background. (Part 1)
Results and Discussion
• Did the three solutions all have the same Rf factors? Were the bands all the same size?
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• What did the different colored bands signify in each solvent for Part 1?
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• What pigments can you associate with the bands? Use what you know about different
photosystems to explain your answer.
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EXPERIMENT 2: MEASURING PHOTOSYNTHESIS
Introductory Questions
• What are you observing in this experiment?
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• Describe the technique for measuring the photosynthetic rate you used in this experiment. What
part of the process of photosynthesis causes the change in pH?
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• What is the osmolarity fluid used in Part 2? Why is this important? Why is it essential to keep it
cool?
The osmolarity fluid utilized in part 2 is the sucrose solution. The sucrose solution is
crucial because it prevents the degradation of spinach and the modification of
chlorplasts. Maintaining a cold temperature is essential for the osmoic process to take
place.
• What is the purpose of Tube 2 in this experiment?
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• Why did you add the solution made in Step 2?
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• What is your hypothesis for the outcome of this experiment?
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Data and Observations
Test
Tube
Chloroplast Solution
Present? Initial Color Final Color
Time Required to
Change Color
(Hours)
1
No Purple/Blue Purple Didn't change. It
stayed the same
within 8 hours
2Yes Purple/Blue Clear/ very light
pigment of green
5.5 hours
3Yes Purple/Blue Clear/ very light
pigment of green
6 hours
Insert a picture of the final color of the solutions in the 3 test tubes with your name and access code
handwritten in the background. (Part 3)
Results and Discussion
• Which tube turned clear in the shortest time? Did this confirm your hypothesis?
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• What part of the photosynthetic process causes the effect observed?
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• How could you modify this experiment to show the effects of different wavelengths of light on
the photosynthetic rate?
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• Some plants (grasses) tend to contain a greater concentration of chlorophyll than others (pines).
Can you develop a hypothesis to explain this? Would it be testable?
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