It is Bright red when combined with oxygen and purple-Blue in the deoxygenated state. Each molecule is made up of a globin (a type of protein) and four heme groups.

• 血红蛋白与氧结合后呈鲜红色,缺氧时呈紫蓝色。血红蛋白的每个分子是由一个珠蛋白(蛋白质的一种)分子和四个血红素基因构成。