What is the Role of DNA and RNA?

By  //  March 20, 2023

Every human being has a different physical appearance than others. They are different in nature also. How it is possible?

If they have the same anatomy then how they are so changed from each other? These were questions that arose in every scientist’s mind when they tried to read the anatomy of humans.

History

A German scientist named Friedrich Miescher discovered the DNA when he was testing the pus of a patient. He observed the precipitated substance in acidic and normal conditions. 

He observed that this substance does not be precipitated in the alkaline solution. Then he did more experiments on it and in 1866 a “nuclein” (previous name of DNA) named substance was discovered. He named it nuclein as it was in the nucleus.  

After that, many scientists did experiments and in 1920, Frederick Griffith discovered it as heredity material. In the 1950’s other two scientists, Watson and Crick discovered the chemical structure of DNA.  DNA can be observed clearly under an electron microscope unlike light microscope.

No one knows the exact year of the RNA discovery but it is said that it might be between the 1890s to 1950 after the discovery of DNA. DNA and RNA have differences in their structures.

DNA  RNA
Name Deoxy ribonucleic acid Ribonucleic acid
OH group  Don’t  have OH at 2nd carbon in the ring  Having OH-group at 2nd carbon in the ring
Helix Double helix  Single helix
Forms B-form  A-form
Bases Adenine(A), Thymine(T), Guanine(G), Cytosine (C) Adenine(A), Uralic(U), Guanine(G), 

Cytosine(C)

Pairing of bases A-T

C-G

A-U

C-G

Function Store and transfer genetic information Act as a messenger between DNA and ribosome
Methyl group  Present  Not present 
Stability  Stable in an alkaline environment  Not stable in alkaline conditions
Self-replication It is a self-replicating substance It is made from DNA when it is needed
Location Nucleus, a small amount in mitochondria Not specific place. It is made in the nucleus. Right after its discovery, it moves in the specific region of cytoplasm according to the type of RNA formed. 
Length  DNA is a very long polymer than the RNA. It might be several meters long RNA varies in size. They are much shorter than the DNA. A single polymer of RNA can be just thousands of bases long.  
Sensitivity It is sensitive to ultraviolet (UV) light. It can be damaged if it is exposed to ultraviolet light. When exposed to ultraviolet light it shows resistivity as compared to DNA. 

Role of DNA and RNA:

Nucleic acid is essential to live organisms. Yet, DNA and RNA are different forms of nucleic acids with specific functions.

DNA is recognized as an information molecule. This information is used to make the larger nucleotides called proteins according to coded instructions. These instructions are stored in the chromosomes. Chromosomes are thread-like structures found in DNA. 

46 chromosomes are found in humans. Instructions for the proteins are distributed among the 46 chromosomes.  Every chromosome has multiple genes in pairs. These genes have coding directions for making proteins. In fact, due to these genes, DNA is called the “house of heredity material ”.

RNA is the major molecule in the formation of protein because it takes instruction from the DNA and transfers it to the ribosome that makes the proteins accordingly. It seems simple but in actuality, three types of RNA involve in this process.

  • Messenger RNA
  • Transfer RNA 
  • Ribosomal RNA

When DNA gets a stimulus for the production of any protein, it makes the messenger RNA transfer the instructions. The production of RNA from DNA is called Transcription.  mRNA takes the information to the ribosome from DNA.

 Here tRNA translates the information and makes a polypeptide chain called proteins. The formation of RNA into protein is called translation. rRNA is the major part of the ribosome. About 60% of it is found in the ribosome. rRNA is responsible for giving the right attachment place to the mRNA.      

DNA is somewhat different from RNA as DNA is double-stranded while RNA is single-stranded. In the case of bases, thymine is replaced by Uracil in the RNA. RNA has ribose sugar while DNA has Deoxyribose sugar. DNA has heredity material, so any damage in DNA will definitely cause any disease.

The disease that is related to the genetic code is called genetic disease.