Question

what are the three differences in transcription and/or the resulting mRNA between prokaryotes and eukaryotes/

Answer 1

Differences between transcription and the resulting mRNA between prokaryotes and eukaryotes:

1) Prokaryotic transcription and translation occur simultaneously in the cytoplasm as there are no separate compartments for nucleus and organelles (no membrane bound organelles).

Eukaryotic transcription occurs in nucleus then the resulting mRNA send to cytoplasm for translation.


2) mRNA is polycistronic in prokaryotes which means one mRNA code for several proteins. They contain many different genes on single mRNA.

mRNA is monocistronic in eukaryotes which means one mRNA code for one protein.


3) In eukaryotes, resulting mRNA undergo post-transcriptional modifications such as capping, polyadenylation, and splicing. After this, resulting mRNA molecules transported to the cytoplasm for protein synthesis.

But in prokaryotes these events do not occur in prokaryotes.

Answer 2

Eukaryotic Transcription takes place inside of the Nucleus. Prokaryotic Transcription takes place in the Cytoplasm. In eukaryotic Transcription, combinational translation and transcription are not possible. In Prokaryotic Transcription, combinational translation and transcription are possible.

Answer 3

Transcription is the process by which genetic information encoded in DNA is used to synthesize RNA molecules, particularly mRNA (messenger RNA). While the basic process of transcription is similar in prokaryotes and eukaryotes, there are several key differences between the two in terms of transcription and the resulting mRNA. Here are three main differences:

1. Complexity of Transcription Machinery: Prokaryotes have a relatively simple transcription machinery compared to eukaryotes. In prokaryotes, transcription occurs in the cytoplasm since there is no defined nucleus. The RNA polymerase enzyme responsible for transcription in prokaryotes consists of a single core enzyme, which can initiate and elongate RNA synthesis on its own.

   Eukaryotic transcription, on the other hand, occurs in the nucleus, which is separated from the cytoplasm by the nuclear envelope. Eukaryotic RNA polymerase, involved in mRNA transcription, is more complex and includes three distinct RNA polymerases: RNA polymerase I, II, and III. Each polymerase is responsible for transcribing specific types of genes. Moreover, the eukaryotic transcription process involves additional regulatory proteins, transcription factors, and enhancers to control gene expression more intricately.

2. mRNA Processing: In prokaryotes, the mRNA transcript produced after transcription is generally ready for translation immediately. It lacks extensive post-transcriptional processing steps. The mRNA in prokaryotes is typically polycistronic, meaning it may contain the information for multiple genes within a single transcript.

   In contrast, eukaryotic mRNA undergoes significant post-transcriptional processing before it becomes mature and can be transported to the cytoplasm for translation. This processing includes the addition of a 5' cap and a 3' poly-A tail, both of which help protect the mRNA from degradation and aid in its export from the nucleus. Additionally, eukaryotic mRNA contains exons (coding regions) and introns (non-coding regions). Pre-mRNA, initially transcribed from DNA, undergoes splicing to remove introns and join exons together, resulting in mature mRNA.

3. Transcriptional Regulation: Prokaryotic transcription is often constitutive, meaning that most genes are transcribed at a constant rate without strict regulation. However, some prokaryotic genes are subject to regulation through the binding of transcription factors and other regulatory elements.

   In eukaryotes, transcriptional regulation is more complex and tightly controlled. The presence of a nuclear membrane allows for compartmentalization, and transcription is influenced by the dynamic interplay of various factors, including transcription factors, enhancers, repressors, and chromatin remodeling complexes. This complexity allows eukaryotes to respond to different environmental cues and developmental signals, resulting in more precise control of gene expression.

These differences in transcription and mRNA processing between prokaryotes and eukaryotes contribute to the diverse gene regulation and cellular complexity observed in eukaryotic organisms.