Rucete ✏ Biology In a Nutshell
1. Introduction
What is CAM Photosynthesis?
CAM (Crassulacean Acid Metabolism) photosynthesis is a special adaptation found in plants that live in arid environments—such as deserts—where water is scarce and there are extreme differences between day and night temperatures.Why Is It Important?
Instead of following the typical C3 or C4 photosynthesis pathways, CAM plants use a unique method to minimize water loss while still performing photosynthesis effectively.2. Detailed Explanation or Comparison
Stomatal Behavior
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CAM plants open their stomata at night to absorb CO₂ and close them during the day to reduce water loss.
CO₂ Fixation and Storage -
At night, the absorbed CO₂ is converted and stored as malic acid inside vacuoles.
Daytime Sugar Synthesis -
During the day, malic acid undergoes decarboxylation to release CO₂, which is then used in the Calvin Cycle to make sugars.
Water Efficiency -
This nocturnal CO₂ uptake allows CAM plants to thrive in dry conditions by conserving water.
Growth Comparison -
CAM plants generally grow more slowly than C3 or C4 plants because CO₂ uptake is limited to nighttime.
3. Formula and Calculation
Night Reaction
CO₂ + PEP → Oxaloacetate → Malic Acid (stored in vacuole)Day Reaction
Malic Acid → CO₂ (via decarboxylation) → Calvin Cycle → Sugars4. Examples
CAM Plant Examples
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Cacti, succulents (e.g., aloe), pineapples, and some orchids
Practical Uses -
CAM plants are used in drought-resistant landscaping and agriculture due to their efficient water usage.
In a nutshell
CAM = Cool At Midnight
Helps you remember that CAM plants open their stomata at night when it's cooler to conserve water.