Often the members of a family are found to have similar characteristics. For example, a father son duo may have blue eyes or two siblings may have same hair color. The reason behind this are the genes present in the cells of these family members. Well, to be more precise the major role played over here is by DNA, also known as Deoxyribonucleic acid. The genetic information of all organisms are stored in DNA and is passed on from one generation to the next with it.
The most important feature of DNA is that it can replicate itself. The genetic information stored in the strands of a DNA helix is replicated into new strand during the process of cell division. The double helix structure of bases are replicated and passed on to each of the new cells formed during the process of cell division.
Structure of DNA
A close look to the structure of DNA reveals its double helix shape, wherein each strand is a polynucleotide chain. The basic units of these polynucleotide chains are monomeric nucleotides. The components of these nucleotides include a phosphate group, a sugar, and four nucleobases. These nucleobases include thymine, guanine, cytosine and adenine. In the structure of DNA, oblique lines can be found connecting the two strands. These oblique lines represent the covalent bonds between the sugar molecules and the phosphate molecules of the nucleotides. Each of these covalent bonds connect a sugar molecule of one nucleotide to the phosphate molecule of the next nucleotide, thereby forming a backbone of sugar and phosphate molecules.
Where is DNA found
During the study of cell structure, cell organelles called chromosomes in the nucleus, carrying the genetic information can be identified. These chromosomes containing DNA, play a major role during cell division. The DNA present in the nucleus of a cel is frequently termed as the nuclear DNA.
One of the most significant cell organelles is mitochondria and it is also known as the powerhouse of the cell. These cell organelles are responsible for the energy supply of the cell. These generate energy for the cells from the consumed food. Some amount of Deoxyribonucleic acid is also present here in the mitochondria. It is generally referred to as the mitochondrial DNA.
Important Functions of DNA
The DNA plays some of the very important functions in the life cycles of the organisms. Carrying the genetic material from a generation to the next generation is the major role played by DNA in the life cycle of organisms. The most significant functions of DNA are listed below.
Genetic information encoding
In the strands of DNA, the four nucleobases of Adenine, Cytosine, Thymine and Guanine are constructed into basic units of genes. The arrangement of these bases along the DNA strands determine the process of protein synthesis. Initially, the cells arrange the genetic material onto the RNA segments. These strands of RNA are re-arranged into units of proteins, re-arranging three of the bases at once.
Replication of the DNA strands
In the double helix structure of DNA, a particular bonding is followed for the nucleobases. The covalent bonds can pair only Thymine and Adenine, and Cytosine and Guanine. In the process of cell division, these strands of the double helix unwind and replicate themselves into new identical strands. The daughter cells so formed in cell division contain a complete set of these identical DNA strands as the genetic information.
Apart from the above-mentioned factors there are other roles of DNA as well. It plays an important role in the expression of the obtained genes by interacting with the proteins of the cells. It allows some of the genes to be expressed whereas other genes exist in the dormant form.