What are the differences between 70s and 80s ribosomes?

Basis of differentiation 

70S Ribosomes

80S Ribosomes

Definition

Are smaller ribosomes found in prokaryotes such as bacteria and also in eukaryotic cells

Are larger ribosomes that occur exclusively in eukaryotes

Occurrence in the Cell

Found in free states in the cytoplasm of prokaryotes and in eukaryotic cell organelles such as mitochondria and chloroplast

Found in the cytoplasm or attached to the Endoplasmic reticulum in eukaryotic cells

Sedimentation Coefficient

70

80

Synthesis 

Synthesized in the cell cytoplasm of prokaryotes

Synthesized in the cell nucleolus of eukaryotes

Size

Smaller than 80S ribosomes

Larger than 70S ribosomes

Type 

Are mostly free-floating 

May be free-floating or membrane-bound

Subunits

Smaller subunit is 30S and larger subunit is 50S

Smaller subunit is 40S and larger subunit is 60S

Components of larger subunit

5-S rRNA, 23-S rRNA and about 34 proteins

5-S rRNA, 5.8-S rRNA, 28-S rRNA and about 40 proteins

Components of smaller subunit

16-S rRNA and about 21 proteins

18-S rRNA and about 33 proteins

Number of RNA molecules

3 RNA molecules

4 RNA molecules

Molecular Weight

2.7-3.0 million Daltons

4.0-4.5 million Daltons

Number of Amino Acids

Around 8,000

Around 16,000

Number of ribosomal proteins

55 protein molecules, with 34 in larger subunit and 21 in smaller subunit

73 protein molecules, with 40 in larger subunit and 33 in smaller subunit

RNA-to-Protein ratio

2:1 (more RNA)

1:1 (equal amount) 

Influence of Antibiotics

Protein synthesis is inhibited by antibiotics

Protein synthesis is not inhibited by antibiotics