Here's why:

* Ribosomes are the protein synthesis machinery: They are complex structures made of RNA and protein that act as the site where amino acids are assembled into polypeptide chains, which then fold into functional proteins.

* Essential for life: Protein synthesis is a fundamental process for all living organisms. Proteins are essential for virtually every cellular function, from structural support and catalysis to signaling and transport.

In addition to ribosomes, cells also need other components for protein synthesis:

* Messenger RNA (mRNA): Carries the genetic code from DNA to the ribosomes.

* Transfer RNA (tRNA): Delivers amino acids to the ribosomes.

* Amino acids: The building blocks of proteins.

* Enzymes: Catalyze the various steps of protein synthesis.

So while ribosomes are the key player in protein synthesis, they rely on other components to function properly.