Prokaryotic Protein Synthesis vs. Eukaryotic Protein Synthesis: What's the Difference?
Edited by Janet White || By Harlon Moss || Updated on October 12, 2023
Prokaryotic protein synthesis occurs in the cytoplasm without a nucleus, while eukaryotic protein synthesis occurs in the cytoplasm and on rough endoplasmic reticulum, directed by a defined nucleus.
Key Differences
Prokaryotic protein synthesis begins in a straightforward manner because of the organism's uncomplicated cellular structure. Eukaryotic protein synthesis, conversely, demonstrates a more intricate process, given the complex nature of the cellular environment. While prokaryotes lack a true nucleus and organelles, eukaryotic cells harbor these structures, directly influencing their protein synthesis mechanisms.
In prokaryotic protein synthesis, the translation of mRNA into protein can occur simultaneously with transcription because there's no nuclear envelope to separate the RNA and ribosomes. Eukaryotic protein synthesis doesn’t permit this simultaneous action because the nuclear envelope separates the processes of transcription (in the nucleus) and translation (in the cytoplasm).
Prokaryotic protein synthesis employs 70S ribosomes found freely in the cytoplasm. Eukaryotic protein synthesis, however, utilizes larger 80S ribosomes, located either freely in the cytoplasm or bound to the endoplasmic reticulum, which further directs the synthesized protein to its respective pathway.
In prokaryotic protein synthesis, mRNA is not subjected to modifications like 5' capping and poly-A tail addition. Eukaryotic protein synthesis witnesses elaborate mRNA processing, including splicing, capping, and the addition of a poly-A tail, which aids in stability, export from the nucleus, and translation efficiency.
Prokaryotic protein synthesis utilizes a Shine-Dalgarno sequence in mRNA for ribosomal attachment, ensuring precise initiation of translation. Contrastingly, eukaryotic protein synthesis commences translation with the help of the Kozak sequence, which facilitates the identification of the start codon and sets the reading frame.
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Comparison Chart
Location of Synthesis
Occurs freely in the cytoplasm.
Occurs in cytoplasm and on rough ER.
Ribosome Size
Uses smaller 70S ribosomes.
Utilizes larger 80S ribosomes.
MRNA Processing
MRNA is generally not processed.
MRNA undergoes capping, tailing, and splicing.
Synthesis and Transcription
Can occur simultaneously.
Occur separately due to the nuclear envelope.
Initiation Sequence in mRNA
Shine-Dalgarno sequence is used.
Kozak sequence is used.
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Prokaryotic Protein Synthesis and Eukaryotic Protein Synthesis Definitions
Prokaryotic Protein Synthesis
Prokaryotic protein synthesis allows concurrent transcription and translation.
In prokaryotic protein synthesis, mRNA is immediately available for translation in the cytoplasm.
Eukaryotic Protein Synthesis
Eukaryotic protein synthesis involves separated transcription and translation due to the nuclear membrane.
The nuclear membrane in eukaryotic protein synthesis ensures transcription and translation occur in distinct cellular compartments.
Prokaryotic Protein Synthesis
Prokaryotic protein synthesis begins with the Shine-Dalgarno sequence guiding initiation.
The Shine-Dalgarno sequence ensures the accurate start of prokaryotic protein synthesis by signaling translation initiation.
Eukaryotic Protein Synthesis
Eukaryotic protein synthesis utilizes 80S ribosomes, partitioned as 60S and 40S subunits.
Eukaryotic protein synthesis engages 80S ribosomes which are larger and more complex than their prokaryotic counterparts.
Prokaryotic Protein Synthesis
Prokaryotic protein synthesis utilizes 70S ribosomes.
The 70S ribosomes engage in prokaryotic protein synthesis directly in the cytoplasm without endoplasmic reticulum involvement.
Eukaryotic Protein Synthesis
Eukaryotic protein synthesis includes mRNA splicing, capping, and tailing.
The mRNA undergoes multiple modifications in eukaryotic protein synthesis, enhancing its stability and translational efficacy.
Prokaryotic Protein Synthesis
Prokaryotic protein synthesis often involves straightforward, unmodified mRNA.
In prokaryotic protein synthesis, the mRNA, lacking extensive modification, is translated as it is produced.
Eukaryotic Protein Synthesis
Eukaryotic protein synthesis is regulated by the nucleus, which stores genetic material.
Eukaryotic protein synthesis necessitates transcription within the nucleus before translation in the cytoplasm.
Prokaryotic Protein Synthesis
Prokaryotic protein synthesis occurs in a cell where no nucleus segregates processes.
Prokaryotic protein synthesis is streamlined due to the absence of a nucleus that would separate transcription and translation.
Eukaryotic Protein Synthesis
Eukaryotic protein synthesis can involve the rough endoplasmic reticulum for protein targeting and transport.
In eukaryotic protein synthesis, ribosomes on the rough ER synthesize proteins that are typically secreted or inserted into membranes.
FAQs
Where does eukaryotic protein synthesis occur?
Eukaryotic protein synthesis occurs in the cytoplasm and on the rough endoplasmic reticulum.
Can transcription and translation occur simultaneously in prokaryotic protein synthesis?
Yes, transcription and translation can occur simultaneously in prokaryotic protein synthesis.
What initiates prokaryotic protein synthesis?
The Shine-Dalgarno sequence on mRNA initiates prokaryotic protein synthesis.
Why is mRNA modification necessary in eukaryotic protein synthesis?
mRNA modification in eukaryotic protein synthesis enhances stability, translation, and nuclear export.
Are there significant temporal separations in the phases of eukaryotic protein synthesis?
Yes, transcription and translation are temporally separated in eukaryotic protein synthesis due to the nuclear envelope.
Do eukaryotic and prokaryotic protein synthesis share similarities in initiation factors?
While both processes involve initiation factors, the specific factors and their functions can differ between eukaryotic and prokaryotic protein synthesis.
Is eukaryotic protein synthesis regulated by a nucleus?
Yes, eukaryotic protein synthesis is regulated by transcription within a defined nucleus.
Does prokaryotic protein synthesis involve mRNA splicing?
Generally, no. Prokaryotic mRNA is not spliced and does not undergo complex processing.
What ribosomal size is involved in eukaryotic protein synthesis?
Eukaryotic protein synthesis involves larger 80S ribosomes.
Do ribosomes bind to the ER during eukaryotic protein synthesis?
Yes, ribosomes can bind to the rough ER during eukaryotic protein synthesis.
How are amino acids brought to the ribosome during prokaryotic protein synthesis?
tRNA molecules bring amino acids to the ribosome during prokaryotic protein synthesis.
Are ribosomes in prokaryotic protein synthesis smaller or larger?
Ribosomes in prokaryotic protein synthesis are smaller (70S).
Does prokaryotic protein synthesis involve the endoplasmic reticulum?
No, prokaryotic protein synthesis occurs freely in the cytoplasm without involving the ER.
Is a nuclear envelope present during prokaryotic protein synthesis?
No, prokaryotic protein synthesis occurs without a nuclear envelope.
How does mRNA reach ribosomes in eukaryotic protein synthesis?
mRNA is transported out of the nucleus to reach ribosomes in eukaryotic protein synthesis.
What role does the Kozak sequence play in eukaryotic protein synthesis?
The Kozak sequence aids in the initiation of translation by positioning the start codon in eukaryotic protein synthesis.
Is mRNA in prokaryotic protein synthesis capped and tailed?
No, mRNA in prokaryotic protein synthesis typically lacks capping and tailing.
What is the key difference in ribosome composition between eukaryotic and prokaryotic protein synthesis?
Eukaryotic ribosomes (80S) are larger and more complex than prokaryotic ribosomes (70S).
What is the Shine-Dalgarno sequence in prokaryotic protein synthesis?
The Shine-Dalgarno sequence helps initiate translation by aligning the ribosome with mRNA in prokaryotic protein synthesis.
How are proteins directed to specific cellular locations in eukaryotic protein synthesis?
In eukaryotic protein synthesis, the rough ER and signal peptides direct proteins to specific cellular locations.
About Author
Written by
Harlon MossHarlon is a seasoned quality moderator and accomplished content writer for Difference Wiki. An alumnus of the prestigious University of California, he earned his degree in Computer Science. Leveraging his academic background, Harlon brings a meticulous and informed perspective to his work, ensuring content accuracy and excellence.
Edited by
Janet WhiteJanet White has been an esteemed writer and blogger for Difference Wiki. Holding a Master's degree in Science and Medical Journalism from the prestigious Boston University, she has consistently demonstrated her expertise and passion for her field. When she's not immersed in her work, Janet relishes her time exercising, delving into a good book, and cherishing moments with friends and family.
