PHOTOSYNTHETIC PATHWAYS

CAM METABOLISM

STUDENT HANDOUT - PAGE 1
PreLab Questions :

1. What four materials are needed by all plants for photosynthesis to take place?

 

2. What two products are produced?

 

3. What is the main difference between the environments of C4 plants and CAM plants?

 

4. What might have caused plants to develop these different pathways?

 

5. Fill in the chart below about the three different pathways:

Characteristics
C3
C4
CAM

a. The type of photosynthesis used by most plants

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b. The type of photosynthesis done by many cactus and succulents

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c. The type of photosynthesis done by corn and sugar cane

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d. Involves the fixation of CO2

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e. Utilizes RuBP carboxylase

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g. Takes place entirely during the daytime

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h. Takes place partly during the night and partly during the day

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i. Uses malic acid to fix and store CO2 until it can be used

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j. Found in environments with high light, high temps, low water

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k. Found in environments with high light, high temps, lots of water

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6. At what time would you expect to find the most malic acid in CAM plants?

 

7. When would you find the least amount of malic acid in CAM plants?

 

8. Write a hypothesis about the acid content of two different CAM plants, one of which has been in sunlight for 24 hours previous to testing and one that has been kept in the dark for 24 hours.