The cell on the left maintains its shape with the support from

Proteins play a role in the physical make-up of a cell or acts as a cytoskeleton - maintains cell shape and figure. These proteins plays different roles and works with nucleic acids and other macromolecules in the cells including cell cycle, cell adhesion, immune response and cell indicators.

Microtubules are one, responsible for the framework and acts as a skeleton of the cell - cytoskeleton needs proteins, also cytoplasm and other organelles of the cell. For a prokaryote or a eukaryote cell to survive, they need protein.