RNA: Ribonucleic Acid

Apart from DNA, RNA or Ribonucleic acid is the other important nucleic acid present inside the cell.

Difference Between DNA and RNA


  1. Double stranded molecule
  2. Contains deoxyribose sugar
  3. Pyrimidine base complementary to Adenine is Thymine
  4. DNA has only one function, that is to bear hereditary in formation
  5. DNA can duplicate on its own


  1. Single stranded molecule
  2. Contains ribose sugar
  3. Pyrimidine base complementary to adenine is Uracil, No thymine in RNA
  4. Many species of RNA such as mRNA, tRNA, rRNA with different functions. RNA is the genetic material in retroviruses.
  5. RNA is synthesized on a DNA template

mRNA or messenger RNA

mRNA or messenger RNA is transcribed in the nucleus to carry information for the protein to be synthesized, from DNA to site of protein synthesis in the cytoplasm. mRNA is transcribed as a strand of complementary bases of one of the DNA strands and carries the information for the synthesis of a particular protein or polypeptide.

tRNA or transfer RNA

tRNA or transfer RNA, also called soluble RNA has a clover leaf structure with loops. One loop recognises the ribosome, the top loop has an ‘anticodon’ to recognise the codon (triplet nucleotide sequence coding for an amino acids) on mRNA. tRNA transfers the amino acids to their respective positions during synthesis of protein.

There are many t-RNAs which differ in their anticodon. Each tRNA is specific for an amino acid and can carry that amino acid to the ribosome during protein synthesis.

rRNA or ribosomal RNA

rRNA is a component of ribosome which are ribonucleoprotein particles containing RNA and proteins. rRNA is synthesized from the information in ribosomal genes in a chromosome. rRNA has a role in protein synthesis.