Difference Between 70S and 80S Ribosomes

Ribosomes are very important cellular organelles that are tasked with synthesizing proteins. Proteins play many roles in our body – from repairing cellular damage to providing structural support. Life, as we know it, is classified into prokaryotes and eukaryotes, each with its own special ribosome structure. Eukaryotic ribosomes are called 80S ribosomes while prokaryotes such as bacteria have a smaller version called 70S ribosomes. Read on to explore more differences between the two.

Difference Between 80S and 70S Ribosomes
70S Ribosome
80S Ribosome
In prokaryotes such as bacteria. Also occurs in eukaryotic cells Exclusively occurs in eukaryotes
In the Cell
Found freely inside the cytoplasm of prokaryotes. ALSO occurs in eukaryotic cell organelles such as mitochondria and chloroplast Found inside the cytoplasm or attached to the Endoplasmic reticulum
Synthesized inside the cytoplasm of prokaryotes Synthesized inside the nucleolus
Small 30S and large 50S Small 40S and large 60S
3 molecules of RNA 4 molecules of RNA
2.7-3.0 million Daltons 4.0-4.5 million Daltons
Sedimentation Coefficient
70 80
Number of proteins
55 protein molecules, with 34 in larger subunit and 21 in smaller subunit 73 protein molecules, with 40 in larger subunits and 33 in smaller subunits
Number of Amino Acids
Around 8,000 Around 16,000
RNA-to-Protein ratio
2:1 (more RNA) 1:1
Influence of Antibiotics
Protein synthesis is inhibited by antibiotics Protein synthesis is NOT inhibited by antibiotics

Further Reading:

Explore more fascinating topics by registering at BYJU’S Biology

Test Your Knowledge On Difference Between 70S And 80S Ribosomes!


Leave a Comment

Your Mobile number and Email id will not be published.



  1. What is the meaning of 70s or 80s