SAT生物考试有很多重点词汇要记忆，看看下面的这篇文章吧，认全所有SAT生物词汇。

　　Carbohydrate monomers are known as monosaccharide. This group includes glucose, C6H12O6, which is a key substance in biochemistry. Sugars that an animal eats are converted into glucose, which is then converted into energy to fuel the animal’s activities by respiration (see Cell Processes).

　　Glucose has a cousin called fructose with the same chemical formula. But these two compounds have different structures:

　　Glucose and fructose differ in one important way: glucose has double-bonded oxygen on the top carbon, while fructose has its double-bonded carbon on the second carbon. This difference is most apparent when the two monosaccharide are in their ring forms. Glucose generally forms a hexagonal ring (six sided), while fructose forms a pentagonal ring (five sided). Whereas fructose is the sugar most often found in fruits, glucose is most often used as the major source of energy for cellular activities.

　　单糖碳水化合物单体被称为单糖。单糖包括葡萄糖，酒精，这是生物化学中一个关键的实质。一个动物通过消化转化为葡萄糖的糖，然后把它们转成能量，供动物消耗，主要是呼吸作用消耗的能量。

　　葡萄糖与果糖具有相同的化学分子式(C6H1206)但是这两个化合物具有不同的结构(我没记错的话是一个有醛基，一个没有)

　　在一个重要的方面葡萄糖和果糖不同：葡萄糖有一个双键对顶端的碳，而果糖的双键碳在第二个碳上。当两个单糖是在其环的形式这种差异是最明显的。 葡萄糖一般形成了一个六角环( 6片面) ，而果糖形成了一个五角环( 5片面) 。在水果中的经常发下的糖是果糖，葡萄糖是作为主要的能源来源，为细胞活动提供能量。