What is a protein that is not associated with a non-protein prosthetic group referred to as?

A protein that is not associated with a non-protein prosthetic group is referred to as a non-conjugated protein. Non-conjugated proteins consist solely of amino acids and do not require additional non-polypeptide components, such as metal ions or organic molecules, to function. This distinguishes them from conjugated proteins, which do have such prosthetic groups that can be essential for their activity.

In contrast, conjugated proteins are those that contain a non-polypeptide unit, while globular and fibrous proteins refer to the shape and structural characteristics of the proteins. Globular proteins tend to be water-soluble and spherical, playing roles in enzymatic and regulatory functions, while fibrous proteins have elongated, structural roles in cells. Understanding the differentiation among these types enables a clearer grasp of protein functionality and composition in biological systems.