LAB7B Exploring Photosynthesis AND Plant Pigments PDF

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Exploring Photosynthesis and Plant Pigments

STUDENT 10/04/2020

1

Dat Data a Activity 1 Data Table 1 Band #

Distance from origin (mm)

Band Color/ Identification

1

1.5 cm

Pale Yellow

2

2.5 cm

Clear

3

4.5 cm

Green

4

5 cm

Light Yellow

Solvent front

5 cm

1. Many things can affect the evaporation of solvents during a chromatography experiment. To allow researchers to compare results across experiments under different conditions, scientists use an Rf value, that is the ratio of the distance the pigment travelled to the distance the solvent travelled. This number remains constant across trials. Calculate the Rf value for each pigment. Pale Yellow 1.5/5 = 0.3 cm Rf Value Clear

2.5/5 = 0.5 cm Rf Value

Green

4.5/5 = 0.9 cm Rf Value

Light Yellow 5/5 = 1 cm Rf Value0

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2

Activity 2 2. My hypothesis is that we are testing to see if we change the light and CO2 does that change the photosynthesis.

Data Table 2 A Time (minute (0.24 s) %) 0 0

Light B (0.24 %) 0

Average of A and B 0

C (0.12 %) 0

D (0.12 %) 0

Average of C and D 0

5

0

0

0

0

0

0

10

0

0

0

0

0

0

15

0

0

0

3

1

2

20

0

0

0

4

1

2.5

25

0

0

0

4

1

2.5

30

0

0

0

5

3

4

35

0

0

0

5

5

5

40

0

0

0

5

5

5

45

0

0

0

7

6

6.5

50

0

0

0

7

6

6.5

55

0

0

0

7

6

6.5

60

0

0

0

7

7

7

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3

Data Table 3 Dark Time A (minute (0.24 s) %) 0 0

B (0.24 %) 0

Average of A and B 0

C (0.12 %) 7

D (0.12 %) 7

Average of C and D 7

5

0

0

0

7

3

5

10

0

0

0

5

3

4

15

0

0

0

4

3

3.5

20

0

0

0

1

0

.5

25

0

0

0

1

0

.5

30

0

0

0

0

0

0

35 40 45 50 55 60

3. Describe the experimental controls used in the Leaf Disk Assay experiment(s). The controls in the experiment were: water temperature, and time reading intervals. 4. Describe the variable(s) used in the Leaf Disk Assay experiment(s). The variables were: Baking Soda concentration, Light, darkness. 5. Compare the test groups of the Leaf Disk Assay. Which treatment (syringe) had the most floating leaf disks after 35 minutes? Syringes C and D with the 0.12% solution of Baking Soda had the most floating leaf disks after 35 minutes. 6. Were there any treatments (syringes) without floating disks?

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4 Syringes A and B with 0.24% Baking Soda in Both Light and Dark that didn’t have any floating disks. 7. How do floating disks correspond to the rate of photosynthesis? The floating leaf disk serves as a measure of photosynthetic activity because oxygen is produced which causes the leaf disks to float at different times. Sodium bicarbonate provides carbon dioxide which causes the leaves to sink. Due to photosynthesis oxygen is produced which causes the leaf to rise. But cellular respiration also occurs which consume oxygen. The leaves rise at different times which is the indicator of photosynthesis. Also the leaves rise in light when photosynthesis is occurring and sink in the dark when no photosynthesis.

8. According to your data, does light intensity affect the rate of photosynthesis? Explain. Yes the light does affect the photosynthesis, the leaves that were floating more of them floated in the light and sunk in the dark. 9. How did the baking soda solution affect photosynthetic rates? Baking soda provides carbon dioxide which causes the leaves to sink. In the higher concentration of Baking Soda 0.24% the leaves DID NOT float at all. The carbon dioxide took the place of the oxygen which is necessary for photosynthesis.

Graph Graph the results below:

Light Time(Minutes) Treatment(0.12%)

Dark Treatment(0.12%)

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5 0 5 10 15 20 25 30 35 40 45 50 55 60

0 0 0 2 2.5 2.5 4 5 5 6.5 6.5 6.5 7

7 5 4 3.5 1.5 0.5 0.5 0 0 0 0 0 0

F lo a ting_ Disk _ G h.x ls x

Floating Disks Over Time 8 Light Treatment(0.12%)

Dark Treatment(0.12%)

7 6 5 4 3 2 1 0 0

5

10

15

20

25

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30

35

40

45

50

55

60...