Light Reaction Web Activity
Name:
Biology
Date:
Period:
To review the process of the light reaction view the animation at:
http://www.csun.edu/~dsb40995/sed646-student.1/simulations/3.html
1. Label the following parts of the leaf on the image to the right:
Palisade Mesophyll
Spongy Mesophyll
Epidermis
Chloroplast
Cuticle
2. Label the following parts of the chloroplast on the image to the right:
Stroma
Grana
Thylakoid
Once you zoom in on the thylakoid membrane you will see five points of interest. Click on the points of
interest to see what happens and answer the following questions.
http://www.science.smith.edu/departments/Biology/Bio231/ltrxn.html
3. At photosystem II what is used to energize the electrons?
4. What molecule supplies photosystem II with electrons?
5. What do the circle, square and triangle shapes between photosystem I and photosystem II represent?
6. What happened to H+ as the electron is passed through the circle, square and triangle shapes?
7. What is used to re-energize the electrons at photosystem I?
8. What molecule is used to accept the high energy electrons produced at photosystem I?
9. Once the electrons are accepted by the electron carrier what molecule is created?
10. Describe the direction that H+ move through ATP synthase? (From the ______ to the ______)
11. What molecule is created when the H+ move through ATP synthase?
Use the link below to view a simulation showing the light reaction of photosynthesis:
http://www.mhhe.com/biosci/genbio/biolink/j_explorations/ch09expl.htm
Click “Skip Intro” to use the simulation
and answer the questions.
In the diagram on the right label
the following:
Photosystem I
Photosystem II
Electron Transport Chain
ATP Synthase
Stroma
Thylakoid Space / Lumen
Table 1: The effects of wavelength on rate of light
reaction
Table 2: The effects of light intensity on rate of
light reaction
To complete the table set the light intensity at 100 lux
and adjust the wavelength to the values on the table.
To complete the table set the wavelength at 650
nm and adjust the light intensity to the values on
the table.
Wavelength
(nm)
400
450
500
550
600
650
700
750
Approximate
color of light
% Maximal
ATP
Light
Intensity
(lux)
0
40
80
120
160
200
% Maximal ATP
1. Use the information from table 2 to predict the % maximal ATP at a light intensity of 220 lux.
2. What combination of light intensity and wavelength is necessary to reach 100% maximal ATP?
3. What two molecules are produced by this process?