Difference Between Prokaryotic And Eukaryotic Translation

The translation process is a fundamental cellular process to synthesize proteins from messenger RNA (mRNA). The primary goal of translation in both prokaryotes and eukaryotes is to maintain the supply of proteins. Still, there are many differences between prokaryotic and eukaryotic translation. Prokaryotic translation occurs in the cytoplasm with simultaneous transcription and translation. In eukaryotic cells, translation takes place in the cytoplasm, but mRNA is transcribed in the nucleus, requiring mRNA export. A brief overview of the translation process and the difference between prokaryotic and eukaryotic translation is given below.

Difference Between Prokaryotic and Eukaryotic Translation

The eukaryotic VS prokaryotic translation processes are outlined below.

Features	Prokaryotic Translation	Eukaryotic Translation
Definition	It is the biological process through which prokaryotic mRNA is translated into proteins simultaneously with synthesis.	It is the biological process through which eukaryotic mRNA is translated into proteins after synthesis.
Location	Cytoplasm	Cytoplasm, on endoplasmic reticulum (ER)
Initiation site	Shine Dalgarno Sequence	Kozak Sequence
mRNA processing	No capping, splicing and polyadenylation of mRNA occurs	5’ capping, splicing and 3’ polyadenylation of mRNA occurs
mRNA stability	Unstable	Stable
mRNA type	Mostly polycistronic	Mostly monocistronic
mRNA lifespan	Few seconds to few minutes	Few hours
Ribosome	50S+30S= 70S	60S+40S= 80S
Synchronisation	Synchronous with transcription process	Discontinuous; translation occurs after transcription
Speed	Faster, 17–21 amino acids/second	Slower, 6–9 amino acids/ second
First amino acid	N-formylmethionine	Methionine
Initiation factor	3	12
Elongation factor	3	2
Release factor	2, RF1 and RF2	2, eRF1 and eRF3

What is Translation?

Translation is the process that synthesis proteins or polypeptide chains in all organisms. This process deciphers the genetic code on a mRNA molecule to produce the amino acids. The amino acids are then joined with peptide bonds. This process is essential for life in both prokaryotes and eukaryotes.

What is Prokaryotic Translation?

Prokaryotic translation occurs in the cytoplasm in three steps: initiation, elongation, and termination. This process requires 70S ribosomes, made of two subunits- 50S and 30S. The ribosome has three sites named A, P, and E. Translation begins at the 5’ end of mRNA as it is still being synthesised. The Shine Dalgarno sequence at the 5’ end of mRNA often marks the starting point for translation. The sequence is recognized by the 16S rRNA component of the 30S subunit.

Three initiation factors, IF1, IF2, and IF3, make a complex, required to start the process and the first amino acid N-formylmethionine is recruited at the P site. Incoming aminoacyl tRNAs bind at A site and deliver the amino acid to the growing peptide chain at P site. Then uncharged tRNAs leave from the E site. GTP provides energy for making the peptide bonds, helped by elongation factors. When the elongation step is complete, the process is terminated by the release factors, freeing the finished polypeptide from the ribosomes.

Significance of Prokaryotic Translation

Translation is a fundamental process in prokaryotes as it is the sole mechanism for synthesising cellular proteins. Proteins are essential for carrying out various functions like cellular metabolism, regulation and for maintaining cellular structure.

• Translation is a key step in gene expression, where the genetic information encoded in mRNA is transferred to polypeptide chains.
• Translation allows prokaryotes to respond dynamically to changes in their environment by synthesising specific proteins.

What is Eukaryotic Translation?

Translation process in eukaryotes is responsible for protein synthesis. Translation can only start when mRNA leaves the nucleus after completion of the transcription process. Like prokaryotic translation, eukaryotic translation also requires ribosomes (80S= 40S+60S) present in the cytoplasm or on the membrane of endoplasmic reticulum (ER). Unlike prokaryotes, eukaryotic mRNA undergoes maturation process, including 5′ capping, polyadenylation, and intron splicing, before translation. The ribosome recognizes the Kozak sequence, the translation initiation site containing the start codon.

Translation can begin either in a cap-dependent or cap-independent manner. In the cap -dependent manner, the initiation factors bind to the 5′ untranslated region (UTR) of mRNAs. The cap-independent manner involves direct binding of the initiation complex to the internal ribosome entry sites (IRES). Elongation factors, eEF-1 and eEF-2, facilitate the addition of amino acids in a growing polypeptide chain. Chain elongation and termination occurs in a similar way that of the prokaryotic system. The release factor eRF1 recognizes all stop codons and eRF3 assists in polypeptide chain release.

Significance of Eukaryotic Translation

Eukaryotic translation is essential for the expression of genetic information encoded in mRNA. The process translates the genetic code in RNA into functional proteins.

• The synthesised proteins are indispensable for maintaining cellular function and homeostasis.
• Translation is crucial for development and differentiation processes in multicellular eukaryotes. During embryonic development and tissue differentiation, specific proteins need to be synthesised in a highly regulated manner in specific cell types.

Conclusion – Difference Between Prokaryotic And Eukaryotic Translation

There are various differences between prokaryotic and eukaryotic translation in their mechanisms and regulation. Prokaryotic translation occurs simultaneously with transcription in the cytoplasm and uses distinct initiation, elongation, and release factors. The translation initiation site also differs between prokaryotes and eukaryotes. Eukaryotic translation initiates only after mRNA processing in the nucleus. Compared to prokaryotic translation, eukaryotic translation is slower and involves a relatively complex initiation step. Although different, both processes ensure timely production of the proteins essential for life.

FAQs on Eukaryotic vs Prokaryotic Translation

What is Found in Prokaryotic Translation But Not in Eukaryotic Translation?

Prokaryotic translation uses 70S ribosomes as machinery and N-formylmethionine as the first amino acid not found in eukaryotic translation.

Why is Translation Faster in Prokaryotes?

Prokaryotic translation is faster than eukaryotic translation because mRNAs are shorter, and 17-21 amino acid residues are added per second, whereas in eukaryotes, only 6-9 amino acids are added per second.

What are the Similarities Between Translation in Eukaryotes and Prokaryotes?

Translation in both prokaryotes and eukaryotes occurs in the cytoplasm and requires ribosomes, mRNA, and tRNA for the process.

What is one Major Difference Between Eukaryotes and Prokaryotes with Respect to Translation?

Prokaryotic translation is faster as it occurs concurrently with transcription, while in eukaryotes, translation starts only after mRNA reaches the cytoplasm following transcription.

Where does Translation Occur in Bacteria and Animal Cells?

mRNA translation occurs in the cytoplasm in both bacteria (prokaryotes) and animal cells (eukaryotes).

How is Translation Different in Prokaryotes than Eukaryotes?

In prokaryotes, translation occurs simultaneously with transcription, whereas in eukaryotes the processes are spatially separated, occurring in different cellular regions.

Where Does the Process of Translation Occur in Prokaryotes and Eukaryotes?

Translation occurs in the cytoplasm of both prokaryotes and eukaryotes.