Photosynthesis Lab
Leaf Disc Assay
F Block
Photosynthesis Lab
An Educational Slide Created By Squade
(Andy, Alex, Colin, Jordyn)
Summary of Findings
In this lab, the effects of plant photosynthesis were
investigated by comparing the rates of
photosynthesis of two plants, spinach and kale. The
rate of photosynthesis was measured the number of
leaf cutouts on the surface per minute. These
floating leaf cutouts show that oxygen, a product of
photosynthesis is produced. We found that the rate
of photosynthesis for the spinach leaves was 8.6
cutouts per minutes, 1.4 less than that of the kale
leaves (10 cutouts per minute.) This difference could
be a result the different amounts of light absorbing
chlorophyll present in each leaf, or a difference in
vascular tissue sizes, which may affect the plant’s
ability to absorb water for photosynthesis.
Photosynthesis Lab
Meghana Yellanki, Tejus Kayiti, Jess Pazienza,
and Anna Hatke
F Block AP Biology
Photosynthetic Rate in Spinach vs Mustard Leaves
Time
(sec.)
# of disks
floating
30
2
60
70
Time # of disks
(sec. floating
)
0
1
30
2
60
3
90
8
120
10
150
13
180
14
210
15 (all
floating)
6
10 (all
floating)
Average rate (Mustard leaf):
10 floats/70 sec. = 0.14
floats/sec.
Average rate (Spinach leaf):
15 floats/210 sec. = 0.071
floats/sec.
Comparing Rates of Photosynthesis
Spinach Leaf Data (Control)
(200 Watt Bulb)
Rate of Photosynthesis (Floats per
second)
Mustard Leaf Data
(Experimental)
Organism
●
●
The average photosynthetic rate of the
Mustard leaves was two times higher than
the rate of the Spinach leaves. This means
that Mustard leaves perform photosynthesis
twice as fast as Spinach.
Only 10 mustard leaf disks were tested
compared to 15 spinach leaf disks in the
control.
Rate of Photosynthesis Lab:
● Both arugula and spinach leaves have a rate of photosynthesis of 20% disks
floating / min, or 2 leaves floating / min.
● From 0-2 min arugula has faster rate of photosynthesis, but spinach has the
fastest rate between 2-3 min and continues to have a greater percentage of
leaves floating until 5 min, at which point both have 100% of leaf chads floating.
Wattage of bulb: 100 watts
-In this lab, photosynthesis was
measured by the production of
oxygen, which caused the leaves to
float
Dani Brake, Julia Waszak, Lauren Canha, Nicole Bardasz
Photosynthesis Lab
By Evan, Akhi, Sam, and Jaymin
Photosynthesis Lab:
Hypothesis: If the photosynthetic rates of romaine lettuce and spinach were compared, spinach will show a higher rate of
photosynthesis
Percentage of Leaflets Rising Over Time
Table 1: Leaflets Rising
Time (sec)
Spinach
(number of
leaflets rising
out of 12) and
(percentage out
of 12)
Lettuce
(number of
leaflets rising
out of 5) and
(percentage of
5)
0
0
0
30
1 (8.33%)
0
60
2 (16.66%)
0
90
5 (41.66%)
2 (40%)
120
7 (58.33%)
5 (100%)
150
10 (83.33%)
-
180
11 (91.66%)
-
210
12 (100%)
-
Percentage of
Leaflets Rising
Time
Conclusion: In conclusion, the lettuce took slightly longer to begin photosynthesis,but when
it started, the rate of photosynthesis in lettuce appears greater than that of spinach (slope of
lettuce line is 10/9 vs 10/21 for spinach). These findings disprove our original hypothesis that
spinach would have a higher rate of photosynthesis than romaine lettuce. This lab can be
related to class because the fact that photosynthesis produces oxygen was the basis of this
experiment. As photosynthesis produced oxygen, it was trapped in the plant, causing the
leaflets to rise. In order to improve this experiment, we could mainly run more trials with the
lettuce to get a more accurate photosynthetic rate and also use an equal number of leaflets
per group (overlapping of leaflets can affect photosynthetic rates so the higher number of
leaflets in the spinach groups could result in overlapping, reducing the photosynthetic rate).
Katherine, Katie, Marissa, Shiva
●
●
Hypothesis: Forsythia leaves will have a slower rate of photosynthesis because the leaves are
darker.
We found that Forsythia leaves have a slower rate of photosynthesis as only 3 total disks were
floating at the end of 600 seconds.
● The Spinach leaves were all floating at 270 seconds.