Those with the mutation produce lactase throughout their lives.
有这个突变基因的一都可以成出乳糖酶。
Different enzymes help to break different linkages - for example amylases break down large polysaccharides like starch into smaller units, whereas lactase, sucrase, and maltase break down lactose, sucrose, and maltose into their monosaccharides.
不同的消化酶能分特定的糖链,比如淀粉酶可以将淀粉等多糖分为小分子的糖,而乳糖酶、蔗糖酶、麦芽糖酶则分别可将乳糖、蔗糖、麦芽糖降为相应的单糖。
Today nearly 90 percent of adult Britons and Scandinavians can chug all the milk they want, whereas down toward the Mediterranean, probably less than 40 percent have lactase persistence, and fewer than ten percent in Africa and Asia.
今天,近 90% 的英国和斯堪的纳维亚成年可以喝他们想喝的所有牛奶,而在地中海地区,可能只有不到 40% 的有乳糖酶耐受性,在非洲和亚洲只有不到 10%。