Which macromolecule is responsible for the structural framework of cells?

Proteins are critical components in forming the structural framework of cells. They play a key role in maintaining the integrity and shape of various cell types. The cytoskeleton, made up of different types of protein filaments, provides mechanical support to the cell, enabling it to maintain its shape and resist deformation.

Additionally, proteins contribute to the formation of various structures such as cell membranes, where membrane proteins play roles in various functions like transport, signaling, and cell recognition. Structural proteins, such as collagen in connective tissues and keratin in hair and skin, further emphasize the importance of proteins in providing structural support across different biological systems.

While amino acids are the building blocks of proteins and are essential for protein synthesis, they do not function independently as structural components. Carbohydrates and nucleic acids serve different biological roles, mainly involving energy storage and information transmission, respectively, rather than providing structural support. Thus, proteins are the primary macromolecules responsible for establishing the framework of cells.