Bugün öğrendim ki: pek çok sukulent bütün gün nefesini tutar. Bunlar, Crassulacean asit metabolizması olarak bilinen özel bir fotosentez tipinde kullanmak üzere gündüze kadar depolayarak yalnızca geceleri karbondioksit solumaktadır.

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Metabolic process **Crassulacean acid metabolism** , also known as **CAM photosynthesis** , is a [carbon fixation](/wiki/Carbon_fixation "Carbon fixation") pathway that evolved in some [plants](/wiki/Plant " Plant") as an adaptation to [arid](/wiki/Arid "Arid") conditions[1] that allows a plant to [photosynthesize](/wiki/Photosynthesis "Photosynthesis") during the day, but only exchange gases at night . In a plant using full CAM, the [stomata](/wiki/Stoma "Stoma") in the leaves remain shut during the day to reduce [evapotranspiration](/wiki/Evapotranspiration "Evapotranspiration"), but they open at night to collect [carbon dioxide](/wiki/Carbon_dioxide "Carbon dioxide") (CO 2) and allow it to diffuse into the [mesophyll cells](/wiki/Mesophyll_cell "Mesophyll cell"). The CO 2 is stored as the four-carbon acid [malic acid](/wiki/Malic_acid "Malic acid") in [vacuoles](/wiki/Vacuoles "Vacuoles") at night, and then in the daytime, the malate is transported to [chloroplasts](/wiki/Chloroplasts "Chloroplasts") where it is converted back to CO 2, which is then used during photosynthesis. The pre-collected CO 2 is concentrated around the enzyme [RuBisCO](/wiki/RuBisCO "RuBisCO"), increasing [photosynthetic efficiency](/wiki/Photosynthetic_efficiency "Photosynthetic efficiency"). This mechanism of acid metabolism was first discovered in plants of the family [Crassulaceae](/wiki/Crassulaceae "Crassulaceae").