【正文】 應(yīng)朝一個(gè)方向進(jìn)行，也可以使其朝逆方向進(jìn)行。 Lesson105. This means that any catalyst that catalyze a reaction in one (.,esterification) also catalyze the reverse(., ester hydrolysis) reaction. To say these things another way, catalysts do not change the energy balance between reactants and products。不能遺忘的是我們吃的食物不是營養(yǎng)素，因此我們應(yīng)當(dāng)考慮到食物中營養(yǎng)化合物總的作用。Lesson 12 concept of food safety has many facets。（ADI是終身攝入某種物質(zhì)而無明顯的而健康危害每日攝入量）29. The Food and Drug Administration (FDA) is authorized by the Food, Drug, and Cosmetic Act to establish standards of acceptable intake of additives and contaminants in foods and to monitor pesticide levels in modities in intrastate shipment.FDA由食品，藥品，化妝品法案授權(quán)去建立一個(gè)食品中的污染物和添加劑的可接受攝入標(biāo)準(zhǔn)，和去監(jiān)視在州內(nèi)批貨的商品的殺蟲劑含量水平。19. These remendations are not individual requirements but are “remendations for the average daily amounts of nutrients population groups should consume over a period of time”. As such, they designed to provide assistance in large scale foodservice operations so that the nutrients in the food offered each day could be pared to the RDA.這些推介量不是個(gè)體需求量，而是“這個(gè)群體在一定時(shí)間內(nèi)所需要消耗的營養(yǎng)素的日需量推介”。s entry (induced fit model). 匹配進(jìn)入酶的活性部位，要么因?yàn)檫@個(gè)分子容易進(jìn)入酶的活性部位，要么因?yàn)槊傅慕Y(jié)構(gòu)進(jìn)行調(diào)整。不飽和脂肪有雙鍵能使烴鏈發(fā)生扭曲，從而使晶體的形成更加困難。木瓜蛋白酶可以在各種蛋白質(zhì)中催化肽鍵的水解，從而可使人體不需要更高特異性酶來專門水解特殊的蛋白質(zhì)。15. Nutrition might be defined as process whereby we obtain the essential nutrients and use them to make many other substances our bodies need. This process would include eating digesting food absorbing and using, or metabolizing, the nutrients it contains.吸收營養(yǎng)素可以被定義為我們所吸收的營養(yǎng)素和利用他們?nèi)ソM建我們需要的其他物質(zhì)的一個(gè)過程。25. The pounds added to foods for special purposes are called food additives. Examples are antioxidants added to oils to prevent rancidity, preservatives to prevent food from spoiling, colorants to make food more appealing, etc. Most of these chemicals are generally regarded as necessary and safe.這些有目地加入到食品當(dāng)中的物質(zhì)被稱為食品添加劑。大多數(shù)這些化學(xué)物質(zhì)一般被認(rèn)為是安全和有必要的。16. Each of these nutrients contains carbon, hydrogen, and oxygen, while protein also contains nitrogen and it