guanin

例句：

1. 1. Guanidine is a compound that can be used as a base in chemical reactions.
   甘氨酸是一种可以在化学反应中作为碱基使用的化合物。
2. 2. The amino acid lysine is an essential component of protein synthesis.
   赖氨酸是蛋白质合成的必需氨基酸。
3. 3. Guanidine compounds are used in the production of fertilizers and pesticides.
   谷氨酰胺化合物用于生产肥料和农药。