Deoxyribonucleic acid or DNA is a molecule that is made up of two polynucleotide chains. These chains are coiled to form a complex double helix structure. It carries genetic instructions for the development, functionality, growth, and reproduction of all living organisms. The two strands of double-stranded DNA store the same biological information. This information is replicated as and when the two strands separate. DNA contains the sugar deoxyribose, phosphates and a unique sequence of the nitrogenous bases Adenine (A), Guanine (G), Cytosine (C), and Thymine (T).
Ribonucleic acid or RNA is a type of polymeric molecule (polynucleotide). Its biological roles include functions such as coding, decoding, regulation, and expression of genes. Ribonucleic acid is an important nucleotide with long chains of nucleic acid present in all living cells. RNA contains ribose sugar, phosphates as backbones, and nitrogenous bases such as Adenine (A), Guanine (G), Cytosine (C), and Uracil (U). DNA and RNA share a common set of nitrogenous bases A, G, and C.
Deoxyribonucleic acid and Ribonucleic acid share similarities in their molecular structure, but there are significant differences that can be noted between the polynucleotides -
Parameters | DNA | RNA |
Acronym | Deoxyribonucleic acid | Ribonucleic acid |
Definition | It is a polynucleotide consisting of deoxyribose sugar and phosphate backbone with bases such as adenine, guanine, cytosine, and thymine | It is a polynucleotide consisting of ribose sugar and phosphate backbone with bases such as adenine, guanine, cytosine, and uracil |
Structure | Double stranded complex double helix structure | Single stranded single helix structure |
Function | It carries genetic instructions on development, form, functionality, growth, reproduction, and making new organisms. Storing genetic information | It carries the genetic codes and performs decoding of the code from the nucleus into the ribosomes in order to generate protein |
Generation | Self-Replication | Synthesized from DNA |
Location | Nucleus and Mitochondria of the cell | Cytoplasm, nucleus and the Ribosome of the cell |
Length | DNA is longer than RNA, up to several centimeters | RNA is variable length; however, it is not longer than DNA |
Nitrogenous bases | Adenine, Guanine, Cytosine, and Thymine | Adenine, Guanine, Cytosine, and Uracil |
Pairing | Adenine-Thymine and Cytosine-Guanine | Adenine-Uracil and Cytosine-Guanine |
Other compositions | 2 deoxyribose sugar, phosphate backbone | Ribose sugar, phosphate backbone |
Stability | Stable in Alkaline condition | Reactive in Alkaline condition |
Sensitivity | DNA is vulnerable to ultraviolet light | RNA is resistant to ultraviolet light |
DNA molecules are very long strands of protein. Long and narrow structures do not fit into cells without having them packed into an enclosure. Thus, the DNA strands are tightly wound to form chromosomes. Therefore, each chromosome contains a single DNA strand with replicated nitrogenous bases. In the human cell, there are 23 chromosomes within the enclosure of the nucleus. For comparison, a chicken’s DNA consists of 39 chromosomes whereas a pig’s DNA consists of 38 chromosomes.
Decoding genetic information and converting them into proteins in the ribosome is essential as proteins play an important role in the functioning of living organisms, proteins act as a catalyst to various chemical reactions within the living system. These chemical reactions take place within the cells in order to maintain their structure and regulate the speed of the internal functioning. In plants these functions include photosynthesis and in animals, it includes respiration and so on. Essentially, life forms cannot function reliably without the generation of protein.
There are three major types of DNA -
The classification of RNA is based on the encoding of its own gene -