Microbiologists describe the processes of transcription and translation as 'coupled' in bacteria. This term indicates that a bacterial mRNA can be undergoing transcription at the same moment it is also undergoing translation. How is coupling of transcription and translation possible in bacteria?

Key Concepts

Transcription

Transcription is the process by which the genetic information encoded in DNA is copied into messenger RNA (mRNA). In bacteria, this occurs in the cytoplasm, where RNA polymerase synthesizes mRNA from a DNA template. This process is crucial for gene expression, as it produces the mRNA that will later be translated into proteins.

Translation

Translation is the process by which ribosomes synthesize proteins using the mRNA transcript as a template. In bacteria, ribosomes can attach to the mRNA while it is still being synthesized, allowing for immediate translation of the mRNA into a polypeptide chain. This efficiency is vital for bacterial survival and rapid response to environmental changes.

Coupling of Transcription and Translation

In bacteria, transcription and translation are coupled due to the lack of a nuclear membrane, allowing ribosomes to bind to mRNA as it is being transcribed. This simultaneous process enables rapid protein synthesis, as the mRNA does not need to be fully processed before translation begins. This coupling is a key feature of prokaryotic gene expression, enhancing efficiency and speed.