C3, C4, and CAM: Adaptations to Climate Change
C3, C4, and CAM Photosynthesis Flashcards | Quizlet
The connection to hot and dry conditions comes from the fact that all the plants will close their stomata in hot and dry weather to conserve moisture, and the continuing fixation of carbon from the air drops the CO2 dramatically from the atmospheric concentration of nominally 380 ppm (2004 value). If the CO2 compensation point is lower on the above scale, the plant can operate in hotter and dryer conditions. The limits are placed by the fact that begins to fix oxygen rather than CO2, undoing the work of photosynthesis. C4 plants shield their rubisco from the oxygen, so can operate all the way down to essentially zero CO2 without the onset of photorespiration.
Types of Photosynthesis: C3, C4 and CAM
During the night, the CAM plant's stomata are open, allowing CO2 to enter and be fixated as organic acids that are stored in vacuoles. During the day the stomata are closed (thus preventing water loss) and the carbon is released to the Calvin Cycle so that photosynthesis may take place.
The main difference between C4 and CAM plants ..
In leafy plants, the process of photosynthesis occurs largely in the leaves. Because of this, all the necessary ingredients need to be present in the leaves for the reaction to take place. Carbon dioxide is absorbed into the leaves from the air, water is routed from the roots to the leaves, and sunlight is absorbed into the leaves through chlorophyll. Chlorophyll is a green pigment inside plant cells called chloroplasts - which also have several other structures within them. Chloroplasts are important because they are where photosynthesis takes place.
These are pathway and CAM photosynthesis
The drawback to C4 photosynthesis is the extra energy in the form of that is used to pump the 4-carbon acids to the bundle sheath cell and the pumping of the 3-carbon compound back to the mesophyll cell for conversion to PEP. This loss to the system is why C3 plants will outperform C4 plants if there is a lot of water and sun. The C4 plants make some of that energy back in the fact that the rubisco is optimally used and the plant has to spend less energy synthesizing rubisco.