What is the basic building block of proteins called?

The basic building block of proteins is called an amino acid. Amino acids are organic compounds that combine to form proteins, which are essential to many biological processes. They consist of a central carbon atom bonded to an amino group, a carboxyl group, a hydrogen atom, and a variable side chain or R group that determines the unique characteristics of each amino acid.

There are 20 standard amino acids that the body uses to create proteins, and the sequence and arrangement of these amino acids in a protein determine its structure and function. The process of protein synthesis involves linking amino acids together through peptide bonds, forming polypeptides that fold into functional proteins.

Other options like glucose, nucleotides, and fatty acids serve different biological roles. Glucose is a simple sugar that provides energy, nucleotides are the building blocks of nucleic acids like DNA and RNA, and fatty acids are components of lipids. Each of these compounds contributes significantly to various metabolic pathways and structural functions in the body, but they do not serve as the building blocks of proteins. Thus, amino acids are uniquely positioned as the fundamental units in protein construction.