Difference DNA And RNA [American Edition]

What Is DNA?

DNA (Deoxyribonucleic acid) is a molecule composed of two chains that coil around each other to form a double helix carrying the genetic instructions used in the growth, development, functioning and reproduction of all known organisms and many viruses.

The two DNA strands are also known as polynucleotides because they are composed of simpler monomeric units called nucleotides. Each nucleotide is composed of one of four nitrogen-containing nucleobases (Cytosine (C), Guanine ( G), Adenine (A) or Thymine (T), a sugar known as deoxyribose sugar and a phosphate group.

The nucleotides are joined to one another in a chain by covalent bonds between the sugar of one nucleotide and the phosphate of the next, resulting in an alternating sugar-phosphate backbone.

What Is RNA?

RNA (Ribonucleic Acid) is a polymeric molecule that plays important biological roles in coding, decoding, regulation and expression of genes.  Just like DNA, RNA is a arranged as a chain of nucleotides. Cellular organisms use mRNA messenger to convey genetic information using the nitrogen bases of Guanine (G), Uracil (U), Adenine (A), and Cytosine (C). Also, unlike DNA which is double stranded, RNA is a single-stranded molecule with shorter chain of nucleotides.

Key Difference

Function

DNA carries the genetic information necessary for the development, functioning and reproduction whereas RNA is mainly involved in protein synthesis; sometimes it also regulates the gene expression.

Structure

DNA is double-stranded. It has two nucleotide strands which consist of its phosphate group, five-carbon sugar (the stable 2 deoxyribose and four nitrogen-containing nucleobases (adenine, thymine, cystosine and guanine). On the other hand RNA is single stranded. It is composed of a phosphate group, five carbon sugar (less stable ribose) and 4 nitrogen containing nucleobases (adenine, uracil, guanine and cytosine).

Location

DNA is found in the nucleus of a cell and in mitochondria. On the other hand, depending on the type of RNA, it can be found in nucleus, cytoplasm and ribosomes.

Stability

Deoxyribose sugar in DNA is less reactive because of C-H bond. This makes it to be stable in alkaline conditions. More, importantly DNA has smaller grooves, which makes it harder for enzymes to attack. On the other hand, Ribose sugar in RNA is more reactive because of C-O (hydroxyl) bonds. This makes it to be stable in alkaline conditions. More, importantly RNA has larger grooves, which makes it easier to be attacked by enzymes.

Propagation

DNA is self-replicating while RNA is synthesized from DNA when needed.

Base Pairing

In DNA, the nucleobases link in the following manner: Adenine links to thymine (A-T) and Cystosine links to Guanine (C-G). In RNA, the nucleobases link in the following manner: Adenine links to Uracil (A-U) and cystosine links to guanine (C-G).

Types

DNA can be classified into two types: Intra nuclear and extra nuclear while RNA can be classified into three types: m-RNA, t-RNA and r-RNA.

Vulnerability  

DNA is highly susceptible to ultra-violet rays damage while RNA is relatively resistant to Ultra-violet rays damage.

Helix Geometry

The Helix geometry of DNA is B-Form. DNA is protected in the nucleus, as it is tightly packed. On the other hand, the helix geometry of RNA is A-Form. RNA strands are continually made, broken down and re-used.

Purine and Pyrimidine

In DNA the number of purine is always equal to the number of pyremidine while in RNA the number of purine will never be equal to pyremidine.

Interaction

DNA can interact with nucleoproteins to form chromatin and chromosomes while RNA can interact with variety of proteins but it cannot form chromatin or chromosome.

Structure

DNA is comparatively long structures with high molecular weight. DNA contains millions of base pairs. RNA on the other hand, is comparatively shot structures, usually between 70-15000 nucleotides.

Helix

DNA is spirally twisted to produce a regular helix while RNA is irregularly folded to produce a secondary helix or pseudohelix.

Hydrogen Bonds

Hydrogen bonds are formed between complementary nitrogen bases of opposite strands (A-T, C-G) while RNA base pairing through hydrogen bonds, occurs in the coiled parts.

Sugar Portion

The sugar portion of DNA is 2-deoxyribose while RNA, the sugar portion is ribose.

Function

DNA transcribes genetic information to RNA.  RNA on the other hand, translates the transcribed message for forming polypeptides.

Lifespan  

DNA is long lived while some RNAs are very short lived while others have somewhat longer life.

Nucleotide Number

DNA contains over a million nucleotides while RNA depending on the type, contains between 70-15000 nucleotides.

Quantity

Quantity of DNA of a cell is fixed while the quantity of RNA of a cell is variable.

Process of Renaturation

Renaturation refers to reconstruction of a protein or a nucleic acid. Renaturation of DNA after melting is slow while renaturation of RNA after melting is quite fast.

Difference Between DNA And RNA In Tabular Form

Summary

What are the 5 main differences between DNA and RNA?

• DNA carries the genetic information necessary for the development, functioning and reproduction. RNA is mainly involved in protein synthesis; sometimes it also regulates the gene expression.
• DNA is double-stranded whereas RNA is single stranded.
• DNA contains deoxyribose sugar whereas RNA contains ribose sugar.
• The complementary base to adenine in DNA is thymine, whereas in RNA, it is Uracil, which is an unmethylated form of thymine.
• It is found in the nucleus of a cell and in mitochondria whereas, depending on the type of RNA, it can be found in nucleus, cytoplasm and ribosome.