Biochemistry) A nitrogenous molecule, either a PYRIMIDINE or a PURINE, that combines with a pentose sugar and phosphoric2碱基：一种含氮的分子，嘌呤碱或者是嘧啶碱，它们和戊糖还有磷酸一起构成核苷酸，核苷酸是核酸的基本结构单位。
Deoxyribose A pentose (five-carbon) sugar that is a component of the nucleotides that make up DNA.脱氧核糖：组成DNA核苷的一种戊糖（五个碳）。