李双,男,5岁,体重增长缓慢,反复发热,咳嗽一年余。平时食欲不振,食物单一,不喜欢吃蛋、奶、蔬菜等食物。反复患有咽炎、扁桃体炎,每年6～8次。服用锌制剂1个月后。食欲明显好转,体重增加,观察3个月,无上呼吸道感染发生。专家诊断该患儿是由于缺锌引发的一系列症状。微量元素是构成人类生命的基础物质,虽然它的含量极少,但是,它们在生理功能方面却起着极为重要的作用。微量元素控制着许多酶类和激素的活性,参与整个代谢过程,根据科学研究发现,生物体内催化生物化学反应的生物催化剂——酶,要比一般化学反应的催化剂的催化活性高出106～1011倍,例如:细菌在适当条件下,20分钟就可以繁殖一代,这主要是酶的催化作用所致,可见酶的催化作用是非常巨大的。人体内的生化反应几乎都是酶促反应,大部分酶的结构成分、活性中心或激活剂都是微量元素。所以说,微量元素与生命是 Li double, male, 5 years old, slow weight gain, repeated fever, cough more than a year. Usually loss of appetite, a single food, do not like to eat eggs, milk, vegetables and other foods. Repeated pharyngitis, tonsillitis, 6 to 8 times a year. After taking zinc preparations 1 month later. Appetite improved significantly, weight gain, observed for 3 months, no upper respiratory tract infection. Experts diagnosed the child is due to a series of symptoms caused by zinc deficiency. Trace elements constitute the basis of human life, although its content is minimal, but they play an extremely important physiological function. Trace elements control the activity of many enzymes and hormones, and participate in the whole metabolic process. According to scientific research, it is found that the biocatalyst - enzyme, which catalyzes the biochemical reaction in organisms, has a catalytic activity 106 to 1011 higher than that of a general chemical reaction catalyst Times, for example: bacteria under appropriate conditions, 20 minutes to breed, which is mainly due to the catalytic effect of the enzyme, showing that the catalytic effect of the enzyme is very huge. Almost all human biochemical reactions are enzymatic reactions, most of the enzyme structure components, active centers or activators are trace elements. So, trace elements and life is