Photosynthesis Lab
Leaf Disc Assay
A Block
Spinach (Control)
Arugula
Number of
Discs
Floating
Time
(seconds)
Number of
Discs
Floating
Time
(seconds)
1
10
1
57
2
20
2
69
3
27
3
79
4
36
4
79
5
36
5
88
6
40
6
88
7
40
7
109
8
40
8
148
9
52
9
155
10
56
10
163
11
66
11
173
12
76
12
224
.16 discs/sec
.05 discs/sec
rate = 0.16 discs/sec
● Spinach had a rate that was more than three
times higher than arugula
● The spinach was darker than the arugula,
indicating higher concentrations of chlorophyll,
which could have led to its higher rate
● The first arugula disc floated in the same
amount of time that 10 spinach discs floated
Spinach Leaf v. Maple Leaf
Photosynthetic Rate
Our group found that the spinach
leaf had a higher photosynthetic
rate than the maple leaf. All the
spinach leaf discs were able to
float to the top of the solution in
under four minutes, whereas not
all of the maple leaf discs were
able to float to the top in the ten
minute span given.
Amy Keum, Sharon Jiang,
Jess Barry, Sydney Kim
Photosynthetic Rate of Spinach vs.
Hibiscus Leaves
Hypothesis: If the photosynthetic rates of hibiscus and
spinach leaves are compared, then lighter green hibiscus
leaves will have a lower rate of photosynthesis than darker
green spinach leaves.
●
●
●
●
●
●
A 200 Watt bulb at a height of 12 inches was used to
provide light for photosynthesis.
150 mL of a sodium bicarbonate and detergent
solution was used for each trial.
No measurable photosynthetic activity was observed
in the Hibiscus leaves1.
The spinach chads began floating after 210 seconds.
Spinach displayed an overall photosynthetic rate of
.13% chads/second while the hibiscus plant displayed
an overall photosynthetic rate of 0% chads/second
over a period of 10 minutes.
This evidence supports not rejecting the hypothesis.
1 Activity
was observed beyond the experimental observation
period, confirming that the leaves were still alive and
supporting the validity of the data.
Michael Colavita, Shanon Fan, Zach Kettering, and Becca Tibbitts
Comparing the Rates of
Photosynthesis Between Spinach
and Rhododendron Plants
By: Anagha Iyengar, Raymond Huang, Julia Tseng, and Jasmine Gutbrod
Spinach (Spinacia oleracea)
→ Edible annual native to central
Asia
→ High nutritional value due to its
abundance of vitamin A, vitamin C,
vitamin K, Manganese, and Iron,
along with other essential minerals
→ Fresh spinach loses much of its
nutritional value after a few days
Rhododendron (Rhododendron
ferrugineum)
→ Type of “woody” plant
→ Considered native to the
Alpine regions but are found
across North America, Europe,
Russia, Asia, Greenland, and
Australia
→ Common ornamental plant
due to its hardy characteristics
and pleasant flowers
Hypothesis + Overview
→ If the rates of photosynthesis of spinach and
rhododendron leaves are tested, then <><><> will
have the highest rate of photosynthesis. <explain
why we think this>
→ The rates were calculated by the number of leaf
discs of each plant type that rose to the surface
after being submerged in a water, sodium
bicarbonate, and detergent solution per minute.
Data
Tim
e
(Mi
n.)
.5
1
Numb
er of
Floati
ng
Spinac
h
Discs
0 1
1.
5
2
5
2.
5
3
9
3.
5
4
9
4.
5
5
5.
5
1 0
6
6.
5
7
7.
5
8
8.
5
9
9.
5
-
-
-
-
-
-
-
-
10
9
Numb
er of
Floati
ng Observing how many leaf discs rise to the top of the solution in ten minutes.
Rhodo
.
Discs
0 0 1 2 2 4 4 4 4 4 6 8 8 8 8 8 8 9 9
Analysis
<conclusionish wrap-up>
Image Sources
http://www.freewallsource.com/green-wallpaper-7620.html
http://echolife.files.wordpress.com/2011/09/baby-spinach-leaves.jpg
http://thelifeofyourtime.files.wordpress.com/2010/11/dscf7286.jpg
Kunal Aggarwal
Lilly Keele
Rachel Morey
Hannah Rosenstein
A Block
Photosynthesis Lab
Independent Variable = Type of plant
Dependent Variable = Rate of photosynthesis
Control = Baby spinach leaves
Experimental = Romaine lettuce
Findings:
● Rate of Photosynthesis of Spinach = 14/360 = 0.039
floats/sec
● Rate of Photosynthesis of Lettuce = 12/360 = 0.033
floats/sec
● Similar overall rate of photosynthesis (both reached
100% floating discs at 6 minutes, but had different disc
totals because not all discs started sunken)
● Occurred at different paces
○ Spinach rate started slower but sped up
○ Lettuce rate started faster but slowed down
(initially appeared to have a higher rate)