What forms the structural basis of the cytoskeleton in cells?

The structural basis of the cytoskeleton in cells is primarily formed by proteins. The cytoskeleton is a dynamic network composed of various protein filaments, including microtubules, intermediate filaments, and actin filaments. These proteins play crucial roles in maintaining cell shape, enabling cellular movement, and facilitating intracellular transport. For example, microtubules are composed of tubulin, while actin filaments are made up of actin proteins, contributing to various cellular activities including muscle contraction and cell division.

Each type of protein filament has unique functions, but together they provide a scaffold that supports the cell's architecture and aids in cell signaling and mobility, highlighting the essential role of proteins in forming the cytoskeleton. Other macromolecules like nucleic acids, carbohydrates, and lipids have their own specific functions in biological systems, but they do not serve as the primary structural components of the cytoskeleton.