* Ribosomes: These are responsible for protein synthesis, a fundamental process for all life. They read the genetic code from messenger RNA (mRNA) and translate it into amino acid chains, which fold into functional proteins.

* DNA (deoxyribonucleic acid): This molecule carries the genetic instructions for the development, functioning, growth, and reproduction of all living organisms. It's essentially the blueprint for life.

While some specialized cells may lack certain organelles, these two are considered universal.