Ch. 8 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.
8-1 Energy and Life
1. Plants, also known as photosynthetic autotrophs and primary producers, carry out photosynthesis.
Explain the term photosynthetic autotroph.
2. What is a heterotroph?
3. On the line below each organism, classify each as an autotroph or a heterotroph.
a) _____________________
b) _____________________
c) _____________________
4. What is the ultimate energy source in plants?
5. ATP is the basic energy source of all cells. Identify which of the reactions are “energy storing” and
which are “energy releasing”.
1. _______________________________
2. _______________________________
6. Where does the energy from the food we eat originally come from?
7. How is ATP different from ADP?
8. How does a cell store most of its energy?
8-2 Photosynthesis: An Overview
9. What occurs during the process of photosynthesis?
10. Write the overall equation for photosynthesis.
11. Plants gather the sun’s energy with light-absorbing molecules called ________________________.
12. What is the principal pigment in plants?
13. Explain why plants look green.
14. Explain how light energy affects a chlorophyll molecule.
15. If a plant is kept under green-colored light for an extended period of time, what will happen to the
plant’s sugar production?
8-3 The Reactions of Photosynthesis
16. Chloroplasts contain saclike photosynthetic membranes called ________________________.
17. What is a granum?
18. The region outside the thylakoid membranes in the chloroplast is called the
________________________.
19. Photosynthesis occurs in two major stages linked by ATP and NADPH. Describe their functions.
Stage/Process
a. Light Reactions
b. Calvin Cycle
Function
20. Identify the labeled parts of the leaf cross section and chloroplast cross section. Then describe the
part’s function.
21. Where are the photosystems, or light-collecting units of photosynthesis, found?
22. In what part of the chloroplast does the Calvin cycle take place?
23. In what part of the chloroplast do the light-dependent reactions of photosynthesis take place?
24. What is the function of the electron carrier, NADP+? Be specific.
25. Photosystems I and II are important parts of the light-dependent reactions of photosynthesis. In
photosystem II, light energy is absorbed by electrons. These high-energy electrons are then passed
down an electron transport chain. The electrons are then passed to photosystem I. In photosystem
I, the electrons are
reenergized by light
energy and used to make
NADPH.
Color the diagram
according to the directions
below:
•
•
•
•
Color the two places
where light energy
enters the reactions
yellow.
Color the hydrogen
ions red.
Color the electrons
green.
Color the thylakoid
membrane blue.
26. Where does light enter the system?
27. What uses energy from the high-energy electrons to transport hydrogen ions across the thylakoid
membrane?
28. Where do the electrons necessary for photosynthesis come from?
29. Where does the formation of ATP take place?
30. How does ATP synthase produce ATP?
31. What are the 3 products of the light-dependent reactions?
32. Where in the chloroplast does the Calvin cycle take place?
33. What does the Calvin cycle use to produce high-energy sugars?
34. What are the 3 products of the Calvin cycle?
35. If there is no light coming into the chloroplasts, how will this affect the Calvin cycle?
36. What are 3 factors that affect the rate at which photosynthesis occurs?
a.
b.
c.
37. When environmental temperatures are too high, the rate of photosynthesis decreases. Explain why.
38. How do plants in dry climates reduce their water loss?
39. The following flowchart represents the reactions of photosynthesis. Fill in the missing information
using the following terms: NADP+, NADPH, H2O, CO2, ATP, ADP