Polysome

Definition

A polysome, or polyribosome, is a complex formed by multiple ribosomes simultaneously translating an mRNA molecule. This structure allows for the efficient synthesis of multiple protein copies from a single mRNA strand.

5 Must Know Facts For Your Next Test

1. Polysomes increase the efficiency of protein synthesis by allowing multiple ribosomes to work on the same mRNA simultaneously.
2. They can be found in both prokaryotic and eukaryotic cells.
3. Electron microscopy often reveals polysomes as clusters or strings of ribosomes along an mRNA molecule.
4. The formation of polysomes is a crucial step in gene expression regulation.
5. Polysomal profiling can be used in research to study translation and identify actively translated mRNAs.

Review Questions

• What is the primary function of a polysome in protein synthesis?
• How do polysomes enhance the efficiency of translation?
• In which types of cells can polysomes be found?

Related terms

Ribosome: A cellular structure that carries out protein synthesis by translating mRNA into polypeptide chains.

mRNA (messenger RNA): A type of RNA that conveys genetic information from DNA to the ribosome, where it specifies the amino acid sequence of the protein products.

Translation: The process by which ribosomes synthesize proteins using mRNA as a template.