多磷酸核苷酸 Nitrogen-containing base Phosphate groups (A.T.C.G in DNA.A.U.C.G in RNA) CH2 Base Base NTP (ribonucleoside triphosphate) OH OH dNTP OH triphosphate) CH2 Base No oxygen H H/ NOP H (ribonucleoside diphosphate) OH OH C H2 ddNTP Base (dideoxyribonucleoside triphosphate) H No oxygen NMP OH OH (ribonucleoside monophosphate) 多磷酸核苷酸