Which structure is an example of a supramolecular complex?

A supramolecular complex refers to a larger assembly of multiple molecules held together by non-covalent interactions, which allows for the formation of complex structures that have specific biological functions. In this context, ribosomes serve as an ideal example of a supramolecular complex because they are composed of ribosomal RNA (rRNA) and proteins that come together to perform the vital function of protein synthesis. The assembly of these components relies on a variety of interactions, including hydrogen bonding, van der Waals forces, and ionic interactions, thus exemplifying the characteristics of supramolecular structures.

The other structures mentioned, such as cell membranes, mitochondria, and the nucleus, while they play critical roles in cellular function, are primarily composed of various biomolecules that form distinct organelles or structures rather than being classified as supramolecular complexes on their own. For instance, cell membranes consist mainly of lipid bilayers with embedded proteins, which do not define them as supramolecular complexes in the same way ribosomes are characterized. Mitochondria and the nucleus are organelles made up of numerous protein and nucleic acid structures but do not fit the specific definition of a supramolecular complex as clearly as ribosomes do.

In conclusion, ribosomes