Photosynthesis Lab
B Block
Michael Colomb | Jack Cusworth
Brian Warner | Sean Macomber
Background
6 CO2 + 6 H2O → C6H12O6 + 6 O2
Spinach Leaves
Deep Green color
Flatter leaves
Slightly wilted
Large amounts of chlorophyll a, chlorophyll b,
and beta-carotene
Kale Leaves
Darker Green
Large amounts of lutein and betacarotene
Curling leaves
Results
Photosynthetic Rate of Kale:
0.025 floats per second
Photosynthetic Rate of
Spinach:
0.033 floats per second
Conclusion
● We observed that the spinach leaf chads had a higher photosynthetic rate
than the kale leaf chads due to the fact that the spinach chads all surfaced
in a smaller amount of time than the kale chads.
● This difference in photosynthetic rate between the two types of leaves
occurred because of the larger amounts of chlorophyll A and B in spinach
which allowed for more photosynthesis, thus increasing the rate.
● The leaf chads all rose to the top of the beaker due to the release of O2 gas,
as a byproduct of photosynthesis, and replaced the water that was in the
chads in the beginning of the experiment.
Conclusion contd.
One way to improve this lab would be to repeat the lab multiple times to
account for error and provide more consistent and accurate data. Another
way to increase the effectiveness of this lab would be to make sure both
sets of leaf chads are placed in the bicarbonate solution for a consistent
amount of time before the tin foil is removed from the top of the beaker and
the timer starts.
Works Cited and Acknowledgements
Works Cited
Isolation of Chlorophyll and Carotenoid Pigments from Spinach. Los Angeles: UCLA, n.d.
PDF.
Lefsrud, Mark, Dean Kopsell, Adam Wenzel, and Joseph Sheehan. "Changes in Kale
(Brassica Oleracea L. Var. Acephala) Carotenoid and Chlorophyll Pigment Concentrations
during Leaf Ontogeny." Scientia Horticulturae 112.2 (2007): 136-41. ScienceDirect. Web.
19 Oct. 2015.
Thanks to the one and only Ms. Albu for the Spinach and Kale leaves and to Seany Mac
and Cheese for the Oak leaves!
Photosynthesis Lab
Julia Devlin, Sakshi Jhawar, Tiffany Lu, Julie Woodward
B Block
Background
BABY SPINACH:
Grown in slight or NO shade areas
Very few veins
Rich, vibrant green leaves
Mostly chlorophyll; also lutein (yellow) and a bit
of carotene (orange)
Soft, juicy leaves-- very penetrable epidermis
Known for its fast photosynthetic rate
BABY KALE:
Grown in cool, damp places; prefers less light
Many veins
Different shade of green-less rich
Baby kale harvested after 1-2 weeks:
Lutein, 2 types of Carotene, Xanthophylls at peak
Low levels of chlorophyll at this time: increases &
maxes @ ~3wks
Thick, tougher leaves-- harder epidermis for coldresistance?
Results
*Note: Our data collection method was very different- we found the total time for all the
chads to float and divided it by the number of chads that floated to get the average floats/
second, seconds/ float, ect.
BABY SPINACH:
Time for ALL floats: 4 min 16.34
sec (256.34 sec)
Floats/second= 0.039
seconds per float= 25.64
BABY KALE:
Time for ALL floats: 5 min 12.13 sec
(312.13 sec)
Floats/second= 0.032
seconds per float= 31.25
Average Reaction Rate Comparison
Average Second/Float Comparison
Conclusions
The leaf type with the faster photosynthetic rate was the baby spinach.
This disproved our original hypothesis.
In baby spinach the pigment with the highest concentration was chlorophyll
In baby kale the pigments with the highest concentrations were lutein, carotene, and
xanthophylls
Because chlorophyll is the chemical responsible for photosynthesis the plant with more of it would have a
higher rate of photosynthesis.
Kale is used to growing in environments with little light, so it is unadapted to highly
evaporative environments such as the intensely lit set up in this experiment. On the
other hand, spinach is adapted to this sort of lighting
Conclusion (cont.)
Our data cannot be compared with the other groups data as we only used 10 leaf
chads as opposed to 20. We also did not measure the number of floats per
minute for 10 minutes. Instead we measured the total time it took for all of the
leaf chads to float to the top, and therefore our rate was derived differently.
If we were to do this experiment again we would use 20 leaf chads instead of 10
and measure the amount of floats in the proper intervals instead of just the
total amount of time to ensure that we have results that are comparable to the
rest of the groups.
Works Cited
Spinach Information:
http://www.mdidea.com/products/proper/proper03103.html
http://christopherking.name/Organic%20I%20Labs/Plant%20pigments%20by%20TLC_files/image013.gif
http://socrates8181nc.tripod.com/id10.html
Kale Information:
https://en.wikipedia.org/wiki/Kale
http://www.sciencedirect.com/science/article/pii/S0304423806005140
http://gentleworld.org/kale-an-easy-beginners-guide-to-growing/#Finding the right spot and time to plant
Leaf Structure and Conclusions Research:
http://w3.marietta.edu/~biol/introlab/Leaves%20and%20Pigments.pdf
https://en.wikipedia.org/wiki/Leaf#Venation_2
http://www.enchantedlearning.com/subjects/plants/leaf/
http://www.botgard.ucla.edu/html/botanytextbooks/generalbotany/shootfeatures/generalstructure/leafcolor/xanthophylls.html
Thanks to Sakshi for the kale!
Photosynthesis Lab:
Leaf Disc Assays
Basil vs. Spinach!
Naqiya M., Trisha K., Esther K., Priya I., Andee S.
B - AP Biology
Introduction/Background
❏ Lighter green color would reflect more and absorb less
light than darker green color due to lower chlorophyll
amounts (and vice versa)
SPINACH
❏ ↓ green pigment = ↓ chlorophyll amount = ↓ light absorption =
↓ photosynthesis rate = ↑ time for the leaf chads to float to the top
❏ Leaf chads float because of oxygen gas produced, and oxygen can be
produced both in and out of the bicarbonate solution
❏ Basil leaves are lighter than spinach leaves, suggesting
lesser chlorophyll amounts and lower photosynthesis rate
❏ Predicted that basil leaf chads would have a lower rate (chads
floating/second) than spinach leaf chads
BASIL
Result
s
This graph shows the number of spinach
and basil leaf chads that were floating
over time.
Average rate for spinach:
-> 18 chads/ 600 seconds =
.03 floats/second --- 3% of discs
Average rate for basil:
-> 13 chads/ 600 seconds =
.02166 floats/second ---~2% of discs
Conclusion
The spinach leaves rose quickly to the top after a few minutes
more chlorophyll allows for more light to enter the chad,
so more electrons are going through the electron transport chain
causing a faster reaction in phosphorylation
– Observation:
The spinach took less time
to float to the surface than it did
for the basil
Progression of spinach leaf chads floating to surface
Continued
– Reasoning:
The darker pigment of spinach = more chlorophyll = more light is able to come in
and excite photosynthesis than it can for the basil
– Redesign/Extension:
More trials
To ensure the accuracy of our results
More types of leaves
Expanding hypothesis rationale
Manipulating different variables in addition to the type of leaf used
Ex. Amounts of light received
Motiwalla, Kagalavadi, Kim, Iyengar, Song
Works Cited
B., Michael. "Basil." Evoo Marketplace. Evoo Marketplace, 2015. Web. 18 Oct. 2015.
Brother, B. "Happy Spinach Vegetable Cartoon." Zazzle. Zazzle, 2015. Web. 18 Oct. 2015.
Busch, Sandi. "What Kind of Food Contains a High Amount of Chlorophyll?" SF Gate. Demand Media, 2015.
Web. 18 Oct. 2015.
Oven, G. S. "Fresh Spinach." Tablespoon. General Mills, 25 Feb. 2013. Web. 18 Oct. 2015.
Slavid, Lisa. "Basil." Peadoodles. Peadoodles, 4 Aug. 2009. Web. 18 Oct. 2015.
Acknowledgements
Thanks to Esther Kim for
the basil leaves!
And Ms. Albu for the spinach leaves
of course 😊
Also, Naqiya says “hi”
from Houston and really
misses her leaf chads!
Photosynthesis Lab:
Leaf Disc Assay
Ali Kea, Brianna Kenney, Victoria Loosigian, Ally Rohlfs
B Block
Background
- Spinach is a C3 plant
- 25 species within the Mint genus
- Our experiment used spearmint, which is a C3 plant
- Spinach is a darker shade of green than the mint
- Pigment affects the rate of photosynthesis
- Our hypothesis was that mint leaves would have a faster photosynthetic rate because it has a
lighter pigment
Spinach
Spearmint
Results
C0nclusion
- We found that spinach leaves floated at a greater rate than the mint leaves
- This proved our hypothesis wrong
- Overall Photosynthetic Rate
- Spinach: 0.0458 floats per second
- Mint: 0.0133 floats per second
- Spinach and mint have different photosynthetic rates because they have different amounts of
pigments and have differently adapted stomata
- The Spinach had a faster reaction rate so it most likely had more light absorbing pigments or
their stomata which let in carbon dioxide faster
- Extension/Redesign
- All of the spinach leaf chads floated before four minutes so we were unable to compare the
mint and spinach photosynthetic rates after four minutes.
- If repeating this experiment, we would complete more trials and add more leaf chads to each
beaker
Works Cited
Picture URLs:
http://www.organic-sourcing.com/spearmint.jpg
http://awaytogarden.com/wp-content/uploads/2010/09/semi-savoy-spinach.jpg
Citations:
"Mint." Encyclopaedia Britannica. Enyclopaedia Britannica, 2015. Web. 18 Oct. 2015.
-
Acknowledgments:
thank you to Victoria and her mom’s herb garden for providing us with the mint leaves
Lettuce Vs. Spinach, The Chad
Race
David Gillett, Mark Dunne, Neehath Malisetty
B: Block
Spinach
Dark green leafy vegetable, that goes through photosynthesis
Spinach contains the chlorophyll a and chlorophyll b pigments
There are 14 photosynthetic chlorophyll pigments in each
monomer with 8 chlorophyll a and 6 chlorophyll b
Both of these chlorophylls are very effective photoreceptors
because they contain a network of alternating single and double
bonds
Romaine Lettuce
Light colored green leafy vegetable with a thick spine
Low level of chlorophyll in the leaf
High chlorophyll a and b ratios
Depleted in components of the light-harvesting chlorophyllprotein complex
Video of the Lettuce Chads
Results
Conclusion
O2 bubbles surrounded the leaf chads causing them to float
Spinach photosynthetic rate was slightly higher
Spinach = Higher photosynthetic rate because Spinach = Darker/More chlorophyll
Extension: Explore other factors that affect photosynthetic rate
distance of lamp from the beaker
light color
temperature
concentration of CO2
Works cited & acknowledgements
Thanks to the Dunn family for providing the lettuce
Thanks to Ms. Albu for the spinach