Which of the following is NOT a function of lipids?

The chosen answer highlights that the backbone of collagen is not a function of lipids. Collagen is a structural protein that provides strength and support in various tissues, including skin, bones, and tendons. While collagen itself is composed of amino acids rather than lipids, lipids serve different roles in the body.

In contrast, lipids are indeed a major source of energy for the body. They are more energy-dense than carbohydrates and are stored as triglycerides in adipose tissue, which can be broken down for energy when needed.

Moreover, lipid derivatives are known to function as hormones and intracellular messengers, playing significant roles in regulating various physiological processes. Examples include steroid hormones like testosterone and estrogen, which are derived from cholesterol.

Additionally, while lipids themselves do not modify proteins directly, certain lipid-related enzymes can influence protein function through post-translational modifications, such as palmitoylation. However, this is distinct from the structural form and function of proteins like collagen.

Therefore, identifying that lipids do not have a structural role as the backbone of collagen clarifies their distinct biological functions and the role of proteins in tissue construction and support.