Those with the mutation produce lactase throughout their lives.
有这个突变基因的人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.
不同的消化酶能分解特定的糖链,比如淀粉酶可以将淀粉等多糖分解为小分子的糖,乳糖酶、蔗糖酶、麦芽糖酶则分别可将乳糖、蔗糖、麦芽糖降解为相应的单糖。
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人可以喝他们想喝的所有牛奶,在地中海地区,可能只有不到 40% 的人有乳糖酶耐受性,在非洲和亚洲只有不到 10%。