Lipids: Are They Villains?

The two best known substances in this organic category are fats and oils.

While these two types of lipids worry many people because they are associated with high levels of blood cholesterol, on the other, they play important roles in metabolism and are fundamental to the survival of most living things. One of the roles of lipids is to function as an efficient energy reserve.

When oxidized in cells, they generate almost twice the amount of calories released in the oxidation of equal amounts of carbohydrates. Another role of lipids is to act as an efficient thermal insulator, especially in animals that live in cold regions. Fat deposits favor fluctuation in the aquatic environment; Lipids are less dense than water.

In addition to these two fundamental types of lipids, there are others that must be remembered for their functions in living things. These are waxes, phospholipids, steroids, prostaglandins and terpenes.

at waxes They exist on the surface of plant leaves and in the skeletons of many invertebrate animals (eg insects and ticks), they act as a waterproofing material. We must not forget the wax deposits that form on our outer ears as a protective function;
the phospholipids They are important components of biological membranes (plasma membrane and many cell organelles);
the steroids they are lipids that act as regulators of biological activities;
at prostaglandins act as chemical messengers in vertebrate tissues;
the terpenes They are present in some biologically important pigments, such as chlorophyll and carotenoids.