methyl group

DNA methylation is the only known covalent modification of DNA molecule. It is accomplished by transfer of the methyl group from S-adenosyl methionine to 5 position of the purine ring of cytosine.

DNA甲基化（DNA Methylation）是目前已知的唯一天然的DNA共价修饰方式，由DNA转移酶催化，将S-腺苷甲硫氨酸上的甲基转移到胞嘧啶嘌呤环的第五位碳原子上。

Codeine has the same structure as morphine, but the phenol group masked as a methyl ether.

可待因也有和吗啡相同的结构, 但是酚基被甲基醚屏蔽了,结果.

The simulation results suggested that the EVAP showed significant effects on the nucleation and growth of the paraffin crystal when the acetate concentration was around 30% and there existed one branched methyl group near the acetate group in each block.

在各种乙烯醋酸乙烯丙烯（EVAP）降凝剂中，当EVAP酯含量在30%左右，且在每个链段含有一个靠近酯基的甲基支链时容易在蜡晶的成核和生长过程中发挥作用。

Genes get switched off when a chemical mark, a methyl group, is added to the DNA.

DNA的甲基化会使基因表达关闭.