Biology Chapter 7

Biology Chapter 7 - but CO 2 cannot enter photosynthesizing...

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summer, whereas crabgrass (C 4 ) takes over in the hot midsummer. C. CAM Photosynthesis 1. CAM (crassulacean-acid metabolism) plants form a C 4 molecule at night when stomates can open without loss of water; found in many succulent desert plants including the family Crassulaceae . 2. At night, CAM plants use PEPCase to fix CO 2 by forming C 4 molecule stored in large vacuoles in mesophyll. 3. C 4 formed at night is broken down to CO 2 during the day and enters the Calvin cycle within the same cell, which now has NADPH and ATP available to it from the light-dependent reactions. 4. CAM plants open stomates only at night, allowing CO 2 to enter photosynthesizing tissues; during the day, stomates are closed to conserve water
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Unformatted text preview: but CO 2 cannot enter photosynthesizing tissues. 5. Photosynthesis in a CAM plant is minimal, due to limited amount of CO 2 fixed at night; but this does allow CAM plants to live under stressful conditions. D. Photosynthesis and Adaptation to the Environment 1. Each method of photosynthesis has its advantages, depending on the environment. 2. C 4 plants are adapted to areas of high light intensities, high temperatures, and limited rainfall. 3. C 3 plants do better in cooler climates. 4. CAM plants do well in an arid environment....
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This note was uploaded on 11/18/2009 for the course BIOL 4 taught by Professor Cooper during the Winter '08 term at Mt. SAC.

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