What do proteins primarily supply in the body aside from building tissues?

Proteins play a crucial role in the body beyond their primary function of building and repairing tissues. One significant role of proteins is their involvement in the production of hormones, which are vital for regulating various physiological processes. Hormones are biochemical messengers that influence metabolism, growth, and mood, among other functions. They are often made up of amino acids, which are the building blocks of proteins. Therefore, the correct answer focuses on the hormone function of proteins, highlighting their importance in maintaining homeostasis and supporting biological functions.

While proteins do not primarily supply oxygen, they do assist in transporting oxygen within the body through hemoglobin, a protein found in red blood cells. Vitamins, minerals, and other nutrients are critical to bodily functions as well, but they are not supplied by proteins themselves. Instead, they must be obtained from diverse dietary sources. In this context, focusing on proteins' role in hormone production highlights their multifaceted contributions to overall health and physiological balance.