guaninen.[化]鸟嘌呤guanine aminohydrolase鸟嘌呤氨基水解酶Guanine insertion enzyme鸟嘌呤插入酶guanine deoxyribonucleoside鸟嘌呤脱氧核苷Guanine phosphoribosyltransferase鸟嘌呤磷酸核糖基转移酶Guanine tRNA-ribosyltransferase鸟嘌呤tRNA-核糖基转移酶guanine nucleotide binding protein鸟嘌呤核苷酸结合蛋白guanine nucleotide exchange factor鸟苷酸交换因子 （GEF）guanine phosphorjbosyl transferase鸟嘌呤磷酸核糖转移酶guanine phosphoribosyl transferaseGPRTguanine nucleotide releasing factor鸟嘌呤核苷酸释放因子

1. Adenine has a purine ring structure.
   腺嘌呤具有嘌呤环的结构。