Ch. 7 Photosynthesis Packet
Name _____________________
Period ________
California State Standards covered by this chapter:
Cell Biology
1. The fundamental life processes of plants and animals depend on a variety of chemical reactions that occur in
specialized areas of the organism's cells. As a basis for understanding this concept:
f. Students know usable energy is captured from sunlight by chloroplasts and is stored through the synthesis of
sugar from carbon dioxide.
6.
Stability in an ecosystem is a balance between competing effects. As a basis for understanding this concept:
d. Students know how water, carbon, and nitrogen cycle between abiotic resources and organic matter in the
ecosystem and how oxygen cycles through photosynthesis and respiration.
Read the appropriate section in the textbook and lecture notes before answering the following questions.
You must put all answers and definitions into your own words for full credit.
The Basics of Photosynthesis
1. Plants, also known as photosynthetic autotrophs and primary producers, carry out photosynthesis.
Explain these terms.
a. photosynthetic autotroph:
b. producer:
2. Identify the labeled parts of the leaf cross section and chloroplast cross section. Then describe the
part’s function.
Outer membrane
Inner membrane
A
D
B
C
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Structure (part)
A
B
C
D
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F
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E
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Function
3. All living cells need ________________ to carry out their activities.
4. All of this energy comes ultimately from the __________________.
5. Photosynthesis is the process in which some of the _______________________ is captured by
plants (primary producers) and transformed into ___________________ used by other organisms
(consumers).
6. Write the balanced chemical reaction for the process of photosynthesis:
A Photosynthesis Road Map:
7. Photosynthesis occurs in two major stages linked by ATP and NADPH.
Stage/Process
Function
a. Light Reactions
b. Calvin Cycle
8. Diagram an overview of the 2 processes involved in photosynthesis. Indicate all Inputs and Outputs
and the direction they are going. I have included some inputs and outputs for you.
H2O
Light
Reactions
Calvin
Cycle
in
in
________
ATP
(Cell location)
________
(Cell location)
Glucose
The Light Reactions: Convert Solar Energy to Chemical Energy
9. chlorophyll:
10. In addition to the primary chloroplast pigment, chlorophyll a, there are other pigments called
accessory pigments. Describe the function of one such accessory pigment, carotenoids.
11. photon:
12. photosystem:
Campbell, Reece, and Mitchell. (2000). Biology: Concepts & Connections, 3rd edition. Pearson, San Francisco.
Use the above diagram and the diagram on page 110 in your book to complete the steps of the light
reactions.
13. The light reactions occur in _________ photosystems, photosystem ______ and photosystem _____.
(number)
A ____________________ is a cluster of several hundred chlorophyll molecules and “acceptor”
(noun)
molecules. The two photosystems have ____________________ forms of ___________________.
(number)
(pigment)
14. The light reaction begins when light energy raises the energy level of photosystem I. The
_________________ is trapped by an electron __________________ and is used to reduce a co(noun)
(noun)
enzyme, NADP+ to NADPH + H+. The electron _______________ from photosystem I is
(verb)
__________________ by an electron from photosystem II.
(verb)
15. In turn, the electron lost from photosystem II is replaced by ____________________ a water
(verb)
molecule. This yields two hydrogens and an oxygen, which combines with another oxygen to form
__________________.
(noun)
16. The energized electrons from photosystem II, pass down a(n) ___________________ and fill the
(noun)
(noun)
space in the reaction center of photosystem ___________________ . As the electrons move from
(number)
one electron acceptor in the electron transport chain to the next, ________________ is released and
(noun)
used to pump the hydrogen ________________ into the thylakoid space against the concentration
(noun)
gradient.
17. The H+ ions then diffuse through an __________________ called ATP synthase, and provide energy
(noun)
for the synthesis of _____________ from ADP.
(noun)
18. The products of the light reaction are:
a.
b.
c.
The Calvin Cycle: Making Sugar from Carbon Dioxide
Campbell, Reece, and Mitchell. (2000). Biology: Concepts & Connections, 3rd edition. Pearson, San Francisco.
The NADPH and ATP are then used in the Calvin cycle (dark reaction) to “fix” CO2 in producing
glucose. Use the above diagram and the diagram on page 112 in your book to complete the steps of the
light reactions.
19. The Calvin Cycle does not require light. The Calvin Cycle takes place in the ________________ of
(noun)
the chloroplast. The cycle consists of four major steps. First, three molecules of ___________ enter
the plant from the atmosphere. ______________, a five-carbon sugar molecule,
__________________ to the CO2.
(noun)
(noun)
(verb)
20. The ________________ that makes this possible is RuBP __________________. It is the most
(noun)
(noun)
abundant protein on earth. This produces six molecules of a three-carbon compound called
_____________________.
(noun)
21. Next, 3-PGA (3-phosphoglyceraldehyde) is phosphorylated and reduced in a two step process, using
the ATP and NADPH from the light reactions to form six molecules of ________________. One
(noun)
glyceraldehyde 3-phosphate is used to make ____________________, and the other five molecules
(noun)
are recycled to remake RuBP so that the cycle can continue.
22. In order to make one molecule of glucose, how many turns of the Calvin cycle must occur?
23. What are the overall reactants and products of photosynthesis?
Reactants (Inputs)
Products (Outputs)
Like most organisms, plants have special adaptations that allow them to survive better in their
environment.
24. What do most plants (C3) do to conserve water on a hot, dry day?
25. What problem can arise if the stomata remain closed too long? Give a detailed explanation.
The Environmental Impact of Photosynthesis
26. What is the greenhouse effect?
27. The greenhouse gases have been linked to global warming. List the greenhouse gases.
28. Describe the predicted results of global warming? Include an explanation of global warming.
29. Describe how photosynthesis from plants helps moderate the greenhouse effect?
30. Describe how deforestation intensifies the greenhouse effect?
31. Describe how the combustion of fossil fuels and wood are contributing to global warming?