The ribosome is an organelle that functions in the process of

Protein synthesis (translation)

Explanation:

Ribosomes may be present free in the cytoplasm or are present on the surface of the rough endoplasmic reticulum. Protein synthesis is the process of synthesis of new proteins wherein the mRNA serves as a template and specifies the amino acid sequence of the proteins.

The mRNA joins ribosomes present in the cytoplasm or on rough ER to initiate the process of protein synthesis. The ribosome moves along mRNA to expose the mRNA codes to the tRNA which in turn carries the respective amino acids from the cell pool. In this way, ribosomes serve as a site for protein synthesis.