例句與造句

1. Quinic acid , used shikimate pathway in e . coli , it is necessary to extend metabolic pathway by introduction of a heterogenous gene qutb into the host cell . double specific enzyme genes arog , qutb or three ones arog , qutb , arob were co - expressed in a single plasmid pbv220 to improve the enzymes " rate - limiting reactions . modifications of e . coli chromosome by both disruption of the arod gene and directed - site insertion of the arob gene resulted in the change of carbon flow redirected into the quinic acid biosynthesis branch
   利用大腸桿菌莽草酸途徑合成新的代謝物奎尼酸，須在宿主細(xì)胞引入異源酶基因擴(kuò)展代謝途徑；串聯(lián)表達(dá)酶基因，同時(shí)適量增加不同種屬的多個(gè)關(guān)鍵酶酶量，改善限速反應(yīng)；利用同源重組進(jìn)行基因整合和基因破壞，改造染色體結(jié)構(gòu)定向改變微生物代謝途徑；目的是將碳代謝流最大程度的引向奎尼酸生成的方向。
2. It's difficult to find rate-limiting reaction in a sentence. 用rate-limiting reaction造句挺難的