Here's why:

* Ribosomes are the protein factories: Ribosomes are complex molecular machines responsible for reading the genetic code (mRNA) and translating it into a chain of amino acids, which then folds into a functional protein.

* Location: Bacterial ribosomes are found floating freely in the cytoplasm, the fluid that fills the cell. Some ribosomes may also be attached to the plasma membrane, particularly those involved in the synthesis of proteins destined for export.

So, the short answer is ribosomes are the sites of protein synthesis in bacteria.