Ribulose biphosphate s (RUBP) A 5-carbon compound that accepts carbon dioxide during photosynthesis.Each molecule is then converted into two molecules of 3-carbon phosphoroglyceric acid.

• 二磷酸核酮糖：一种五碳化合物，可以在光合作用中接受一分子CO2，转化为2分子3碳的3-磷酸甘油酸。