What are the main differences between eukaryotic and prokaryotic gene expression?

The process of gene expression is the mechanism by which genetic information is used to create functional gene products such as proteins. Both eukaryotic and prokaryotic organisms utilize gene expression to produce these gene products, but there are significant differences in how they carry out this process.

Prokaryotic gene expression is simpler than eukaryotic gene expression. Prokaryotes have a single, circular chromosome and do not have a nuclear membrane. The genes are located in the cytoplasm, and the ribosomes are free-floating. The process of gene expression in prokaryotes is divided into three steps: transcription, translation, and post-translational modification. In prokaryotes, transcription and translation can occur simultaneously since they do not have a nuclear membrane. This means that translation can begin while the mRNA is still being synthesized.

Eukaryotic gene expression is more complex and is regulated more extensively than prokaryotic gene expression. Eukaryotic organisms have multiple, linear chromosomes and a nuclear membrane, which separates transcription from translation. In eukaryotic cells, transcription takes place in the nucleus and is followed by post-transcriptional processing of mRNA, including capping, splicing, and polyadenylation. After mRNA leaves the nucleus, translation occurs in the cytoplasm with the assistance of ribosomes. Unlike prokaryotes, eukaryotic gene expression is regulated by transcription factors and epigenetic modifications such as DNA methylation and histone modification. These modifications can either promote or inhibit gene expression, allowing eukaryotic organisms to respond to internal and external stimuli.