Earlier we said that the entire nuclear membrane contains these holes known as nuclear pores. But what exactly is a nuclear pore? Well, a nuclear pore is not exactly an empty hold. Nuclear pores are actually protein complexes that extend throughout the entire nuclear membrane. And these protein complexes help transport biomolecules such as RNA, ribosomal units, ribosomal proteins, as well as polymerase between our nucleoplasm and our cytosol, the cytoplasm, this region here of our eukaryotic cell. Now, a polymerase is basically a type of enzyme, a type of protein that plays an important role when we translate, replicate or when we transcribe our DNA molecules.