why does transcription, translation and mRNA degradation occur concurrently in prokaryotes
Transcription, translation, and mRNA degradation occur concurrently in prokaryotes to ensure efficient use of resources and rapid response to changes in the environment.
In prokaryotes, transcription and translation happen in the same compartment, the cytoplasm, allowing the ribosomes to immediately bind to the newly synthesized mRNA and start protein synthesis. As soon as mRNA is transcribed, ribosomes begin translating it into proteins, while the mRNA is still being synthesized. In this way, the time between transcription and translation is minimal, and protein production can occur without delay.
Additionally, mRNA degradation occurs quickly in prokaryotes due to the presence of endonucleases and exoribonucleases that degrade the mRNA molecule. This allows the cell to swiftly adjust its protein production levels in response to changing environmental conditions. If a particular mRNA is no longer needed, it is rapidly degraded, freeing up resources for other essential functions.
Overall, the concurrent occurrence of transcription, translation, and mRNA degradation in prokaryotes allows for quick and efficient response to changing environmental conditions, conserving resources and energy needed to sustain the cell.
In prokaryotes, transcription, translation, and mRNA degradation occur concurrently because of a few reasons:
1. Lack of nucleus: Prokaryotic cells do not have a distinct nucleus. This means that transcription and translation can occur in the same cytoplasmic space without any physical separation. The newly synthesized mRNA is immediately available for translation by ribosomes while it is still being transcribed.
2. Coupled transcription and translation: In prokaryotes, transcription and translation can be coupled. As the RNA polymerase synthesizes an mRNA molecule, ribosomes can simultaneously bind to the growing mRNA strand and start translating it into polypeptides. This allows for a rapid and efficient production of proteins.
3. Polygenic transcription: In prokaryotes, multiple genes are often transcribed together as a unit called an operon. This means that a single mRNA molecule can carry the information for multiple proteins. As a result, translation can occur while transcription is still ongoing for other genes within the operon.
4. Rapid turnover of mRNA: Prokaryotes exhibit a relatively fast turnover of mRNA molecules. This means that mRNA molecules are quickly degraded by ribonucleases after translation, making the nucleotides available for new rounds of transcription. This allows for efficient recycling of RNA molecules and helps in maintaining a fine-tuned regulation of gene expression.
Overall, the concurrent occurrence of transcription, translation, and mRNA degradation in prokaryotes allows for a rapid response to environmental changes and efficient production of proteins.