In the dark reactions of photosynthesis, CO2 is added to a five-carbon sugar-phosphate known as Naim 10:29 Cell Energetics and Division In the dark reactions of photosynthesis, CO2 is added to a five-carbon sugar-phosphate known as A. cyclic AMP. B. NADH. C. NAD+. D. RuBP. E. CAM. Answer: D Learn More : Share this Share on FacebookTweet on TwitterPlus on Google+