Fractionation of carbon isotopes in oxygenic photosynthesis Calvin cycle during the day, when stomata are closed to prevent water loss, and the light reactions can drive the necessary ATP and NADPH production. This pathway differs from C4 photosynthesis because CAM plants separate carbon by storing fixed CO in vesicles at night, then transporting it for use during the day. Thus, CAM plants temporally concentrate CO to improve Rubsico efficiency, whereas C4 plants spatially concentrate CO in bundle sheath cells. The distribution of plants which use CAM photosynthesis includes epiphytes (e.g., orchids, bromeliads) and xerophytes (e.g., succulents, cacti). In Crassulacean acid metabolism, isotopic fractionation combines the effects of
What You Need (The Twilight Zone) What You Need (The Twilight Zone) "What You Need" is episode 12 of the American television anthology series "The Twilight Zone". It is based on the short story of the same name by Lewis Padgett (Henry Kuttner and C. L. Moore). Pedott , a peddler, has the curious ability to give people exactly what they need before they need it. He enters a coffee shop where he first gives a woman a vial of cleaner. Then he gives a down-on-his-luck ex-baseball player a bus ticket to Scranton, Pennsylvania. Moments later, the ball player receives a phone call at the cafe