Short Notes For Neet Cam Plants
Table of Contents
[CAM Pathway](#CAM Pathway)
[CAM Plants Examples](#CAM Plants Examples)
[Frequently Asked Questions](#Frequently Asked Questions)
CAM Pathway
CAM plants are those which fix carbon dioxide through the Crassulacean Acid Metabolism (CAM) pathway. This pathway was first observed in plants of the Crassulaceae family. These plants are typically found in arid and dry climates, and have adapted the CAM pathway to help reduce water loss and photorespiration. Examples of CAM plants include cacti, pineapple, and more.
CAM Photosynthesis
The CAM pathway is adapted in plants to allow them to perform photosynthesis under stress. This pathway reduces photorespiration, thereby increasing the efficiency of photosynthesis.
The process of CAM plants reducing water loss during the daytime by absorbing carbon dioxide at night has the following steps:
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Stomata open at night
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Carbon dioxide is absorbed
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Water loss is reduced during the daytime
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In mesophyll cells of the chloroplast, the first step of carbon dioxide fixation is the combination of CO2 with PEP (phosphoenolpyruvate) to form 4 carbon oxaloacetate (same as C4 plants). This reaction is catalysed by PEPcarboxylase and occurs at night.
2. Oxaloacetate is converted to malate and other C4 acids, which are then stored in vacuoles at night.
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During the daytime, stomata remain closed, thus preventing gas exchange.
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Malate is transported out of the vacuole, while CO2 is released through decarboxylation.
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The CO2 enters the Calvin cycle and undergoes carbon fixation, completing the process. Accumulation of CO2 around RuBisCO increases the efficiency of photosynthesis and reduces photorespiration.
CAM Plants Examples
- Cacti
- Pineapple
- Agave
- Orchid
CAM plants, which are mostly xerophytic, also possess the CAM pathway. This pathway is present in some aquatic plants, such as Hydrilla, Vallisneria, etc. In aquatic plants, the CAM pathway is triggered by the scarcity of CO2, due to slower diffusion in water and less competition from other photosynthetic plants during the night.
Some Common Examples of CAM Plants
- Pineapple
- Cactus
- Agave
- Orchid
- Ice Plant
Orchids, Cacti, Aloe, Pineapple, Agave, Moringa, Some species of Euphorbia and Bromelioideae, etc.
Frequently Asked Questions
Examples of C3, C4 and CAM Plants
- C3 Plants: Rice, Wheat, Barley, Soybean, Potato
- C4 Plants: Corn, Sugarcane, Millet
- CAM Plants: Pineapple, Cactus, Agave
The majority of trees, plants and shrubs are C3 plants. Examples include: wheat, rice, oats, and soybeans. Plants in the tropical region show C4 pathway to minimize water loss. Examples include: bermudagrass, maize, and sorghum. Additionally, CAM plants use a separate pathway to reduce water loss through photorespiration. Examples include: cacti and pineapple.
Examples of CAM Plants
- Pineapple
- Cactus
- Agave
- Ice Plant
- Orchid Cactus
- Jade Plant
- Pineapple, Orchids, Bromeliads, Cacti, Quillworts, Water Lobelia, Tape Grass, Water Pygmyweed, etc.
