Thus, operationally, gram for gram of stored triglyceride has far less mass than an energetically equivalent store of, for example, starch . The degree of saturation of a fatty acid affects particularly the fatty acid melting point. Why this occurs can be most readily seen when observing the effect of lack of saturation on the three dimensional configuration of fatty acids . Double bonds place kinks in hydrocarbon chains and kinked hydrocarbon chains have lower melting points than not kinked hydrocarbon chains. See text figure 1030.1 .
Different organisms live in different environments having different typical ambient temperatures.
Having different degrees of saturation of fatty acids allows the maintenance of a reasonable degree of fluidity of components consisting of fatty acids . In warm environments including that of mammalian bodies or where tropical plants live, fatty acids tend to be saturated . Phospholipids are very important for cellular functioning because they form the structural basis for of cellular membranes. You should be able to recognize the basic ring structure of a sterol such as that presented in the illustration below. There are two reasons that fats are more efficient at storing chemical energy than are carbohydrates.