Deoxyribonucleic Acid |
Ribonucleic Acid |
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Strands |
- DNA is mostly double-stranded, helical in shape, and antiparallel strands encircling each other.
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- RNA is mostly single-stranded, and sometimes folded to form double strands.
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Sugar Base |
- The DNA molecule contains 5-Carbon deoxyribose sugar as the sugar backbone. It has one oxygen less than ribose sugar.
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- RNA Molecule contains ribose sugar as sugar backbone.
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Nitrogenous base |
- DNA molecule has Adenine, Guanine (Purines), Thymine, and Cytosine (Pyrimidines).
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- RNA molecule contains Adenine and Thymine (Purines) and Cytosine and Uracil (Pyrimidines).
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Replication |
- DNA is self-replicating. It makes a copy of itself inside the cell using cellular machinery.
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- RNA is formed by the transcription of DNA.
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Location |
- DNA is found in the nucleus of the cell. It is also present inside some cell organelles like Mitochondria and Chloroplasts of eukaryotic cells.
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- 5. RNA is mostly located in close association with ribosomes outside the nucleus and in the cytoplasm.
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Length |
- DNA is a relatively long and large molecule with several thousand to billions of nucleotides. A rare Japanese flower named Paris japonica sports an astonishing 149 billion base pairs.
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- RNA is relatively shorter and smaller in size. The size of RNA ranges from (25000 base pairs to 2 million base pairs).
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Function |
- DNA functions to transfer genetic information in cellular organisms. DNA also transcribes into mRNA for protein synthesis.
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- RNA acts as a genetic material only for some viruses. Protein is synthesized out of mRNA.
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Types |
- DNA based on its structure is classified into five types. A-DNA, B-DNA, C-DNA, D-DNA ,and Z-DNA.
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- The most common types of RNA are tRNA, mRNA, rRNA, and snRNA. Besides there are miRNA, siRNA, lncRNA, and other many other types of RNA which have a role in gene regulation.
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UV resistance |
- DNA is susceptible to UV radiations. It changes the geometry and shape of DNA causing mutations and damaging effects.
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- RNA is much more resistant to UV degradation than DNA.
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Stability |
- DNA is a highly stable molecule. It is more stable under alkaline conditions. That is because DNA lacks a hydroxyl group on the 2' position in each sugar group.
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- Naturally, RNA is more reactive than DNA. RNA is not stable in alkaline conditions.
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Immunogenicity |
- DNA is a weak immunogen with low antigenic activity. Only a few structural genes and certain nucleotide sequences might show an immune response.
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- Most RNAs are immunogenic. They readily elicit an immune response.
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Packing |
- DNA is packed into Chromatin by coiling with histone proteins and nucleoproteins. The 23 pairs of chromosomes are DNA packed together.
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- RNA is in close association with ribosomes. They do not undergo supercoiling with nucleoproteins.
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Quantity of DNA |
- A quantity of DNA inside a cell is fixed. Cells might contain DNA as genomic DNA, Plasmids, or inside cell organelles.
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- The quantity of RNA inside the cell might vary depending on its physiological state.
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Half life |
- The latest estimations show the half-life of DNA is approx. 521 years
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- The half-life of mRNA depends on RNA type. However, it is assumed that mRNA has a half-life of about 10 hours, tRNA up to 80 hours, and tRNA up to 7.8 days.
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Detection |
- DNA is analyzed by Southern Blotting.
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- RNA is analyzed with Western Blotting.
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Inheritance |
- During cell division, DNA is replicated and inherited into the daughter cells.
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- RNA does not inherit. However, it is transcribed in the daughter cells after cell division.
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Staining with Cationic Dyes |
- DNA stains Blue/ Green with methyl green. It has a high affinity with phosphate radicals in the DNA helix.
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- RNA stains red with Pyronin Y. This dye does not have an affinity for phosphate radicals but intercalates between negatively charged RNA molecules.
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Catalytic activity |
- DNA does not possess catalytic activity.
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- Some exceptional RNAs carry out catalytic activity. It is present in various small ribozymes, the catalytic center of ribosome and spliceosome, and even on some self-splicing group I and II introns.
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Chargaff's Rule |
- DNA follows Chargaff's rule. This rule states DNA from any species of any organism should have a 1:1 stoichiometric ratio of purine and pyrimidine bases.
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- RNA doesn't follow Chargaff's rule. It appears practically impossible for them because they are single-stranded.
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Grooves |
- The folds of DNA helix have smaller grooves. This saves the DNA from most enzymatic attacks.
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- RNA has larger grooves and thus is more vulnerable to hydrolytic enzyme attacks.
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