What is the definition of ribisome?

A ribosome is a complex molecular machine found within all living cells that serves as the site of protein synthesis.

Here's a breakdown of its key features:

Structure:

* Made up of two subunits: A large subunit and a small subunit, each composed of ribosomal RNA (rRNA) and proteins.

* Found in the cytoplasm: In prokaryotic cells, ribosomes are free-floating. In eukaryotic cells, they can be free in the cytoplasm or attached to the endoplasmic reticulum (ER).

* Function: Ribosomes act as the "workbench" for protein synthesis, reading the genetic code from messenger RNA (mRNA) and assembling amino acids into polypeptide chains.

Function in Protein Synthesis:

1. mRNA binding: The small subunit binds to the mRNA molecule.

2. tRNA binding: The large subunit binds to transfer RNA (tRNA) molecules, which carry specific amino acids.

3. Peptide bond formation: The large subunit catalyzes the formation of peptide bonds between amino acids, creating a polypeptide chain.

4. Protein release: Once the polypeptide chain is complete, it is released from the ribosome.

In summary, ribosomes are essential cellular components that translate the genetic information encoded in mRNA into functional proteins. Without them, cells could not produce the proteins necessary for life.