Question

Explain what is meant by the coupling of transcription and translation in bacteria. Does coupling occur in bacterial and/or eukaryotic cells? Explain.

Short answer

Coupling of transcription and translation refers to the simultaneous occurrence of these two processes. It occurs in bacterial cells due to the lack of a nucleus, enabling the two processes to happen simultaneously in the cytoplasm. On the other hand, in eukaryotic cells, these processes are decoupled because the nucleus separates transcription and translation. Thus, the mRNA needs to go through certain modifications before it leaves the nucleus and enters the cytoplasm, where translation will take place.

Step-by-step solution

Understanding Coupling of Transcription and Translation

Coupling of transcription and translation refers to the process where translation begins while the mRNA is still being synthesized. In other words, while a gene in the DNA is being transcribed to make mRNA, that mRNA strand is being used to create proteins at the same time.

Explaining Coupling in Bacteria

In bacteria, the processes of transcription and translation are closely coupled. This is due to the lack of a nucleus in bacterial cells, which means that the processes can occur simultaneously in the cytoplasm as soon as the mRNA is transcribed from the DNA.

Understanding Coupling in Eukaryotic Cells

Eukaryotic cells, on the other hand, do not experience this sort of coupling. This is because eukaryotes possess a nucleus that separates the two processes. Thus, transcription occurs within the nucleus, and the mRNA has to undergo some modifications before it can be exported from the nucleus to the cytoplasm for translation to occur.