生命原质有四种重要类型,其中的三种是按照其结构的相似性来划分的:由氨基酸组成的蛋白质,属碳水化合物的多羟醛或酮,以及属核酸的多核苷酸。类脂化合物是根据其物理性质的相似性来确定的,它们是在诸如苯、三氯甲烷、或乙醚等非极性溶剂中的可溶物。类脂化合物中由于憎水基团的存在而呈现多种多样的构型。 There are four important types of life-forms, three of which are grouped according to their structural similarity: proteins composed of amino acids, polyhydric aldehydes or ketones that are carbohydrates, and polynucleotides that are nucleic acids. Lipid compounds are identified based on the similarity of their physical properties, which are solubles in non-polar solvents such as benzene, trichloromethane, or diethyl ether. Lipid compounds in the presence of hydrophobic groups present a wide variety of configurations.