Difference between 70S and 80S type ribosome?
1. They occur only in eukaryotic cells.
2. They occur inside the cytoplasm of eukaryotes either freely or attached to ER.
3. The ribosomes are larger in size with a length of (300—340 A) and breadth (200—240 A).
4. The sedimentation co-efficient is 80.
5. They are comparatively heavier, 4.0—4.5 million Daltons.
6. The two subunits are 40S and 60S.
7. The rRNAs of BOS ribosomes are 28S + 5.8S + 5S in larger subunit and 18S in smaller subunit.
8. The ribosomes possess less of rRNA as compared to protein (40: 60).
9. 80S ribosomes are synthesized inside the nucleolus.
10. It contains about 73 protein molecules, 40 in larger subunit and 33 in smaller subunit.
11. Protein synthesis is not inhibited by common antibiotics like chloramphenicol.
Difference # 70S Ribosomes:1. 70S ribosomes are found both in prokaryotes and eukaryotes.
2. The ribosomes are found freely inside the cytoplasm of prokaryotes and matrix of plastids and mitochondria of eukaryotes.
3. They are comparatively smaller with a length of (200—290 A) and a diameter of (170— 210 A).
4. The sedimentation coefficient is 70.
5. 70S ribosomes are comparatively lighter, 2.7—3.0 million daltons.
6. The two subunits are 30S and 50S.
7. The rRNAs of 70S ribosomes are 23S + 5S (larger subunit) and 16S (smaller subunit).
8. The ribosomes contain more of rRNA than protein (60:40).
9. 70S ribosomes are synthesised in the cytoplasm of prokaryotes and matrix of semi-autonomous cell organelles.
10. It possesses about 55 protein molecules, 34 in larger subunit and 21 in smaller subunit.
11. Protein synthesis is inhibited by antibiotics like chloramphenicol.