Here's a breakdown:

* Ribosomes are the cellular machinery responsible for protein synthesis. They read the genetic code from messenger RNA (mRNA) and use that information to link amino acids together in a specific order, creating a protein.

* Ribosomes can be found in two main locations:

* Free ribosomes: Found floating in the cytoplasm, they produce proteins that will be used within the cell itself.

* Bound ribosomes: Attached to the endoplasmic reticulum (ER), they produce proteins that will be exported out of the cell or sent to other organelles.

So, while the instructions for making proteins come from the DNA in the nucleus, the actual assembly of proteins occurs in the ribosomes.