Comparison between DNA and RNA

NUCLEIC ACIDS

Comparison between DNA and RNA

DNARNA
Found mainly in the chromatin of the cell nucleusMost of RNA (90%) is present in the cell cytoplasm and a little (10%) in the nucleolus.
2. Never present in free state in cytoplasm2. May be present in free state.
3. Normally double-stranded and rarely single-stranded.3. Normally single-stranded and rarely double-stranded.
4. DNA has both ‘sense' and ‘antisense' strands.4. The sequence of an RNA molecule is the same as that of the ‘antisense' strand.
5. Sugar moiety in DNA is 2′-deoxyribose (hence the nomenclature) which contains an H atom at C-2.5. Sugar moiety in RNA is ribose (hence the nomenclature) which contains a 2′-hydroxyl group.
6. Sugars in DNA are in the C2′ - endo form.6. Sugars in RNA are in the C3′ - endo form.
7. The common nitrogenous bases are adenine, guanine, cytosine and thymine (but not uracil).7. The common nitrogenous bases are adenine, guanine, cytosine and uracil (but not thymine)
8. Base pairing is inevitable during which adenine pairs with thymine and guanine with cytosine.8. In case pairing takes place, adenine pairs with uracil and guanine with cytosine.
9. The base ratios (A/T and G/C) are necessarily around one.9. It need not have complementary base ratios.
10. Base pairing involves the entire length of DNA molecule.10. Base pairing takes place in only the helical regions of RNA molecule, which amount to roughly half (50%) of the entire RNA molecule.
11. DNA contains only few unusual bases.11. RNA contains comparatively more unusual bases.
12. DNA is of 3 types:12. RNA is of 5 types:
-----> filamentous (double helical or duplex),-----> viral RNA,
-----> circular or-----> mRNA and
-----> single-stranded.-----> rRNA
-----> tRNA
-----> double-stranded RNA.
13. It consists of a large number of nucleotides (up to 3-4 million) and has, therefore, high molecular weight.13. It consists of fewer nucleotides (up to 12,000) and has, therefore, low molecular weight.
14. DNA is alkali-stable.14. RNA is alkali-labile.
15. DNA stains blue with azureph thalate.15. RNA stains red with azureph thalate.
16. DNA acts as a template for its synthesis.16. RNA does not act as a template for its synthesis.
17. DNA on replication forms DNA and on transcription forms RNA.17. Usually RNA does not replicate or transcribe.
18. During replicatin, exonuclease is needed.18. During biosynthesis, exonuclease is not needed.
19. DNA undergoes mutation.19. RNA does not undergo mutation.
20. DNA is the usual genetic material.20. RNA is the genetic material of some viruses only.
21. DNA is stained green with a dye, pyronin.21. RNA is stained red with pyronin.