CAM Plants

Definition

CAM (Crassulacean Acid Metabolism) plants are a group of plants that utilize a specialized photosynthetic pathway to efficiently capture carbon dioxide during the night and minimize water loss during the day. This adaptation is crucial for survival in arid environments where water availability is limited, allowing these plants to thrive in conditions that would be unfavorable for other types of plants.

5 Must Know Facts For Your Next Test

1. CAM plants open their stomata at night to take in carbon dioxide, which is then stored as malate for use during the day when photosynthesis occurs.
2. This unique method allows CAM plants to maintain high water-use efficiency, making them well-suited for hot, dry climates.
3. Common examples of CAM plants include succulents like cacti, aloe vera, and certain orchids, which have adapted to conserve water.
4. During the day, CAM plants close their stomata to prevent water loss while still utilizing the stored malate for photosynthesis.
5. CAM metabolism can also be found in some C3 and C4 plants under extreme drought conditions as a survival strategy.

Review Questions

• How do CAM plants adapt their photosynthetic process to conserve water in arid environments?
  • CAM plants adapt by opening their stomata at night instead of during the day to capture carbon dioxide. This allows them to reduce water loss since temperatures are cooler and humidity is usually higher at night. The captured carbon dioxide is converted into malate and stored until daytime when it can be used for photosynthesis, enabling these plants to effectively conserve water while still performing vital metabolic processes.
• Discuss the similarities and differences between CAM and C4 pathways regarding their adaptations to environmental conditions.
  • Both CAM and C4 pathways are adaptations that enhance photosynthesis in hot and dry environments. However, they operate differently: CAM plants fix carbon dioxide at night, whereas C4 plants fix it during the day but with a specialized mechanism that helps minimize photorespiration. While both strategies improve efficiency under stress conditions, CAM is particularly suited for extreme aridity, while C4 is advantageous in high light intensity and temperature settings.
• Evaluate the ecological significance of CAM plants in their native habitats compared to other plant types.
  • CAM plants play a critical ecological role in their native habitats by providing food and shelter in environments where other plant types may struggle to survive. Their ability to efficiently use water allows them to thrive in arid conditions, contributing to biodiversity. Additionally, they help stabilize soil, reduce erosion, and offer habitat for various organisms. This unique adaptation ensures that even in challenging climates, these plants can sustain ecosystems that rely on their presence.

Related terms

Photosynthesis: The process by which green plants and some other organisms use sunlight to synthesize foods with the help of chlorophyll, primarily converting carbon dioxide and water into glucose and oxygen.

C4 Pathway: A photosynthetic pathway that enhances the efficiency of carbon fixation in certain plants, allowing them to thrive in high light and temperature environments while reducing photorespiration.

Stomata: Small openings on the surface of leaves that allow for gas exchange, including the uptake of carbon dioxide and the release of oxygen and water vapor.