How does transcriptional control differ in prokaryotes and eukaryotes?

Prokaryotic gene expression is primarily controlled at the level of transcription. Eukaryotic gene expression is controlled at the levels of epigenetics, transcription, post-transcription, translation, and post-translation.

Can bacteria transcribe eukaryotic genes?

In bacteria, transcription and translation can occur simultaneously in the cytoplasm of the cell, whereas in eukaryotes transcription occurs in the nucleus and translation occurs in the cytoplasm. Bacteria have a σ-factor that detects and binds to promoter sites but eukaryotes do not need a σ-factor.

How do bacterial and eukaryotic gene expression differ?

Prokaryotic gene expression (both transcription and translation) occurs within the cytoplasm of a cell due to the lack of a defined nucleus; thus, the DNA is freely located within the cytoplasm. Eukaryotic gene expression occurs in both the nucleus (transcription) and cytoplasm (translation).

Is the genetic code different in prokaryotes and eukaryotes?

The DNA of prokaryotes is much more compact because it contains much less non-coding DNA in and between the genes compared to eukaryotes. In prokaryotes genes can be transcribed together into one mRNA, these groups of genes are called operons. In eukaryotes most of the DNA does not code for a protein.

How is transcription regulated in prokaryotes?

The regulation of gene expression in prokaryotic cells occurs at the transcriptional level. There are two majors kinds of proteins that control prokaryotic transcription: repressors and activators. Inducer molecules can increase transcription either by inactivating repressors or by activating activator proteins.

How is the process of transcription and translation different in eukaryotes and bacteria?

Bacteria have an interesting answer. In bacteria, mRNA is translated into protein as soon as it is transcribed. Thus, in eukaryotes, while transcription occurs in the nucleus, translation occurs in the cytoplasm. In other words, eukaryotic transcription and translation are spatially and temporally isolated.

How does transcription and translation occur in eukaryotes?

Prokaryotic transcription occurs in the cytoplasm alongside translation. Prokaryotic transcription and translation can occur simultaneously. This is impossible in eukaryotes, where transcription occurs in a membrane-bound nucleus while translation occurs outside the nucleus in the cytoplasm.

How are genes turned on and off in prokaryotes?

For prokaryotes, most regulatory proteins are negative and therefore turn genes off. Here, the cells rely on protein–small molecule binding, in which a ligand or small molecule signals the state of the cell and whether gene expression is needed.

How does transcription affect gene expression?

Transcription factors are proteins that regulate the transcription of genes—that is, their copying into RNA, on the way to making a protein. Transcription factors help ensure that the right genes are expressed in the right cells of the body, at the right time.

What is the difference between prokaryotic and eukaryotic transcription?

The initiation and regulation of transcription is more extensive than prokaryotes. Another major difference between prokaryotes and eukaryotes lies in the fact that the mRNA in eukaryotes is processed from the primary RNA transcript, a process called maturation.

How is RNA synthesized in prokaryotic and eukaryotic cells?

Let us make an in-depth study of transcription (synthesis of RNA) in prokaryotes and eukaryotes. In prokaryotic organisms transcription occurs in three phases known as initiation, elongation and termination.

Why do bacterial transposons carry genes for antibiotic resistance?

As many bacterial transposons also carry genes for antibiotic resistance apart from gene for transposase and by the nature of transposable element, the genes move or translocate from one DNA to another and from chromosome to plasmid and vice versa. This results in genetic flux of antibiotic resistance genes in bacterial population.

Where does the initiation of transcription occur?

Signals for the initiation of transcription occur in the promoter sequence which lies directly upstream of the transcribed sequence of the gene. The promoter contains specific DNA sequences that act as points of attachment for the RNA polymerase.