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DNA and RNA

This Study material on DNA and RNA discusses the basics of DNA and RNA, the types and functions in detail

Nucleic acids are specific large molecules in the cells present in all organisms. DNA and RNA are the two primary nucleic acids. These acids are a combination of sugar molecules, phosphate groups, and nitrogenous bases. DNA’s double helix structure resembles a twisted ladder, whereas the structure of RNA resembles a hairpin.

Although RNA and DNA seem to be the same, they perform different functions. 

Let us start with the definition of DNA and RNA. 

DNA (Deoxyribonucleic Acid)

DNA or Deoxyribonucleic Acid is a group of molecules responsible for transmitting genetic instructions or hereditary materials from parents to offspring. 

DNA is a nucleic acid that composes nucleotides. Nucleotides are the basic building blocks of DNA. Every nucleotide consists of phosphate groups, sugar, and nitrogenous bases. A nucleotide contains one of the four types of nitrogenous bases: Adenine, denoted by A, Thymine, denoted by T, Guanine, represented by G, and Cytosine, denoted by C.  

Types of DNA

There are majorly three types of DNA. These include – 

  • A-DNA – a right-handed double helix. 
  • B-DNA – a right-handed helix and the most common DNA conformation. 
  • Z-DNA – Unlike others, the Z-DNA is left-handed DNA. 

Functions of DNA

DNA can be determined as a genetic material responsible for carrying all the hereditary information. DNA is responsible for storing genetic information and performs several other functions as well. They are as follows:

  • Replication or self-duplication of DNA is an enzyme-catalysed process, where the two strands of DNA unwind, and each strand serves as a pattern for the new strand synthesis. This new strand is identical to the original.
  • Cellular metabolism is a function of DNA, where it integrates a complex set of biochemical pathways devoted to the maintenance of cell functions.
  • DNA fingerprinting is a method of isolating and identifying the variable elements within DNA.
  • Transcription is the process to copy the information in mRNA. 
  • Gene therapy is a technique to alter the genes within your body to stop or cure any disease. This is another major function of DNA.
  • When a DNA gene gets damaged or changed to alter the message carried by that gene, this is called a mutation. This is another function of DNA.

RNA (Ribonucleic acid)

RNA or ribonucleic acid helps in the synthesis of proteins in the human body. This nucleic acid is credible for generating new cells in the human body. It is usually achieved from the DNA molecule. RNA has a single strand and a single ribose sugar molecule. Therefore, it is named ribonucleic acid. RNA has nitrogen bases such as guanine, adenine, cytosine, and thymine. Adenine and uracil are regarded as the crucial and primary building blocks of RNA, and both of them shape base-pair with the support of two hydrogen bonds. 

Types of RNA 

There are multiple types of RNA, which are as follows – 

Transfer RNA [tRNA]: The tRNA is responsible for choosing the right amino acid or protein required by the body to help ribosomes. It is placed at the endpoints of each amino acid. This is also named soluble RNA, and it constructs a connection between the mRNA and the amino acid.

Ribosomal RNA[rRNA]: The rRNA is located within the cytoplasm of a cell, where ribosomes are found. In all living cells, the rRNA plays an important role in the translation and synthesis of mRNA into proteins. The rRNA is mainly formulated of cellular RNA and is the most dominant RNA within the cells of all living beings.

Messenger RNA[mRNA]: mRNA works by transmitting the genetic material into the ribosomes and passing instructions regarding the proteins required by the body cells. As per their functions, these are referred to as messenger RNA. 

Functions of RNA 

RNA is found in living organisms on the Earth, including viruses, plants, bacteria and animals. Here are the primary functions of RNA.

  • It promotes DNA translation into proteins.
  • It acts as an adapter molecule during protein synthesis.
  • It functions as a messenger between ribosomes and DNA. 
  • RNA is termed as the carrier of all genetic information.
  • RNA allows ribosomes to pick the right amino acid. 

Conclusion

Nucleic acids play an important role in the storage and transfer of genetic data from one cell to another. DNA is responsible for transferring genetic data and has other functions as well, like DNA fingerprinting, etc. RNA is responsible for protein synthesis required by the body.