Final answer:
A protein segment is composed of amino acids, which include an alpha carbon atom bonded to an amino group, a carboxyl group, a hydrogen atom, and a unique R group. Myelin's main components are lipids and proteins, and nucleic acids are built from nucleotides.
Step-by-step explanation:
The components of a protein segment are amino acids. Proteins are polymers made from the monomers known as amino acids. Each amino acid has a fundamental structure that includes an alpha (a) carbon atom. The a-carbon is bonded to four different groups: an amino group (NH2), a carboxyl group (COOH), a hydrogen atom, and a variable side chain or R group that is distinctive for each amino acid. The R group is what gives each amino acid its unique properties, influencing the structure and function of the protein it's part of. In the context of myelin, which was mentioned in the provided question segments, the main macromolecular components are lipids and proteins. As for the building blocks of nucleic acids, they are nucleotides, which consist of a sugar, a nitrogenous base, and a phosphate group.