Proteins are primarily built from which of the following?

Proteins are primarily built from amino acids, which are organic compounds composed of carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur. There are 20 different amino acids that combine in various sequences to form proteins, making them essential for many biological functions. Each protein has a unique sequence and structure that determines its specific function in the body, such as catalyzing biochemical reactions as enzymes, providing structural support, and facilitating communication between cells.

In contrast, nucleotides are the building blocks of nucleic acids like DNA and RNA, which store and transmit genetic information. Monosaccharides are simple sugars that serve as the building blocks for carbohydrates, which are primarily energy sources and structural components in cells. Fatty acids are components of lipids, which include fats and oils, and are important for energy storage, membrane structure, and signaling. Each of these other biomolecules plays critical roles in biological systems but does not directly contribute to the formation of proteins.