What is a key characteristic of β-Barrel membrane proteins?

The correct answer identifies a notable feature of β-Barrel membrane proteins, highlighting their structural design and functional role in biological membranes. β-Barrel membrane proteins are characterized by their unique configuration, where multiple β-strands (the "barrel" aspect) fold together to form a stable structure that spans the membrane. This architecture allows them to form large pores or channels through which substances can pass.

The mention of "large doors" metaphorically conveys their ability to facilitate the transport of molecules, not just limited to small ions, but potentially larger macromolecules such as proteins or peptides under specific conditions. It's important to recognize that while they can create pathways for various substances to traverse the membrane, they do not typically accommodate entire proteins in a straightforward manner without additional mechanisms or contexts.

The other options describe characteristics that do not align with the established functions and presence of β-Barrel proteins. For instance, while they are found in both prokaryotic and eukaryotic cells, they are not exclusive to one type of cell. Their role extends beyond just ion transport and is more diverse, including transporting nutrients and waste products. Lastly, β-Barrel proteins are not permanently anchored to the cytoskeleton; rather, they exist as part of the lipid bil