Which organelle makes the proteins that are needed by the cell?


A ribosome is a particle-like cell organelle made of RNA (ribonucleic acid) and ribosomal proteins that serve as the site for protein synthesis in the cell.

The ribosome reads the sequence of the messenger RNA (mRNA) and, using the genetic code, translates the sequence of RNA into a sequence of amino acids (a process called Translation).

Ribosomes can function in a “free” form in the cytoplasm, called free ribosomes. However, they can also “settle” on the endoplasmic reticulum (ER) to form “rough endoplasmic reticulum (RER).” Ribosomes in the close association with the endoplasmic reticulum can facilitate the further processing of newly made proteins.


[In this figure] An analogy for ribosomes in a factory.
Ribosomes work like machines to translate the code sequence of mRNA into a protein. Scientists like to call ribosomes, the molecular micro-machines, to admire how exquisite the ribosomes’ design is!

Extended read:

Ribosome function and their structure a

Ribosome – protein factory – definition, function, structure, and biology

  • What is a ribosome? A quick definition
  • Ribosomes structure
  • Ribosome function – protein translation
  • Do prokarytes have ribosomes?
  • The discovery of ribosomes
  • Where are ribosomes located inside a cell?
  • How many ribosomes in a cell?
  • Where are ribosomes made?
  • What is a Polysome?
  • What does co-translational translocation mean?
  • What is the ribosome binding site?
  • What is the ribosome profiling?
  • Ribosomes under a microscope