英语语法分析

Its first limiting amino acid was methionine plus cystine.

它的第一限制性氨基酸为蛋氨酸+胱氨酸。

When higher levels of toxic compounds are present, more methionine is needed.

如果当前有毒物质水平升高，需要更多的谷胱甘肽。

Methionine levels also affect the amount of sulfur-containing compounds, such as glutathione, in the liver.

蛋氨酸含量影响肝脏含硫化合物的数量，如谷胱甘肽。