DNA vs RNA - Structure, Differences and Comparison

  Deoxyribonucleic acid (DNA) and Ribonucleic acid (RNA) are the most important molecules in biology, responsible for the storage of genetic information that underpins all life. They are both linear polymers, consisting of Penrose sugars, phosphates and Nitrogenous bases, but there are some key differences which separate the DNA & RNA. Let's learn about that difference.

1). Chemical Differences between DNA and RNA :

• DNA stands for Deoxyribonucleic acid mean one oxygen atoms is messing on the second carbon OH group, only Hydrogen atom is present.
   While, RNA stands for Ribonucleic acid means a complet ribose sugar is present with OH group at the second number of carbon.

• DNA has for basic Nitrogenous bases which are Adenine (A), Guanine (G), Cytosine (C) and Thiamine (T).
  While, RNA also has four bases, forth base as Uracil (U) insted of Thiamine (T).

  • The difference between Thiamine and Uracil lies in the methyl group, Thiamine has an external methyl group while Uracil don't have methyl group.

DNA is a Double Stranded molecule, while RNA is a Single Stranded molecule.

  •  DNA is a double helical molecule mean double helix and these two strands are twisted on each other to form a spiral arrangements.
  •   While, RNA is a single helix and can wrap with each other to fold.

DNA is a stable molecule, while RNA is and unstable molecule and the life of RNA is very short as compare to DNA.

• DNA molecule is very long molecule up to 3 billion base pairs in humans.
While the strands of RNAs are very short as compared to DNA, largest RNA may be few thousand
bases only.

Structure of Nucleic acids DNA & RNA

2). DNA & RNA Type Differences

• DNA has three basic types :
  - A Type DNA,
  - B Type DNA,
  - Z Type DNA.
While, RNA has more than 30 valid known types like
Transcriptional RNAs :
Regulatory RNAs,  Post- modification RNAs and Viral RNAs etc.

3). DNA & RNA Structural Difference :

• DNA structure is consisted of Exons (Coding sequence) and Introns (non-coding sequence) both portions.
While, RNA strand contains only Exons, Introns are removed after splicing machanism

• DNA is wrapped around Histone proteins, although histones are not part of DNA but still histones are compulsory for coiling of DNA and stability.
  Similarly RNA don't have any kind of histone proteins.

• DNA strand can coil around itself to condense.
  While, RNA strand fold by interaction with it's own chain into secondary and tertiary structure.

• DNA has transposable elements  which can jump from one locus to  other. Similarly RNA don't have such elements.

4). DNA & RNA Functional difference :

• DNA have it's own information in terms of genes which encode into RNA and then into proteins to build or regulate function in organisms.
  While, RNA is formed from DNA and them function as massenger or regulator element.

• DNA can not function directly, while some RNAs like regulatory RNAs function directly without going into proteins.

5). DNA & RNA Location Difference :

• In Eukaryotes DNA is present in nucleolus only. In eukaryotes RNA is formed in Nucleous then migrate to cytoplasm.
- In Prokaryotes DNA is in specific area in cytoplasm called as nucleoid, while in Prokaryotes RNA moves freely in cytoplasm.

6). Evolutionary Difference between DNA & RNA :

•  DNA is considered as secondary molecule with respect to evolution an it is thought as evolved from RNAs.
  While the primary genetic molecule which is thought to be made from raw during origin of living things is RNA. So RNA evolved First