Every living being is made up of millions of microscopic structures known as cells. These cells contain various organelles which have an individual function. Among the organelles in the cell, the cell nucleus is the most important since it contains DNA or deoxyribonucleic acid. We are all familiar with the term DNA and have heard it many times. The interesting fact about DNA and RNA is that both are composed of the same material and are polymers of adenosine triphosphate (ATP).
What is Deoxyribonucleic Acid?
DNA, which is also known as deoxyribonucleic acid in medical terms, is a nucleic acid which is present in the cell nucleus of all living things. DNA is also known as the ‘building block of life’ since it holds genetic information about the previous generation which is passed on to the next. This is the reason why DNA is sometimes referred to as a blueprint. Apart from maintaining genetic information of the parent, DNA also plays a major role in many important functions of life.
The DNA molecule is composed of sugar and phosphate molecules, which form a polymer of nucleotides in DNA. This chain of nucleotides is what makes up DNA. The sugar molecules which form the four bases of DNA, adenine, cytosine, guanine and thymine, are essential for the DNA replication process. The two polynucleotide strands are intertwined with each other and form complementary pairs of the bases through the process of hydrogen bonding. The phosphate and sugar groups that bond the nucleotides are sometimes called the backbone of the DNA helix structure. The cell contains chromosomes, which hold the strands of DNA and genes which are attached to it. There are 23 pairs of human chromosomes (or 46 chromosomes) in the body, which control various factors. The genes hold the genetic code like the color of the eyes, body structure and hair color etc.
The DNA research was first carried out in the year 1889, when a well-known Swiss physician and biologist Friedrich Miescher stumbled upon the presence of this nucleic acid during one of his researches. It was this eminent researcher who discovered DNA, which he called ‘nuclein’. Later, two other well-known scientists, William Astbury and Phoebus Levene, researched on the structure and the constituents of DNA. In the year 1953, two other biologists James Watson and Franklin Crick, with the help of Rosalind Franklin conducted a detailed study and discovered that the human DNA consisted of two strands interlocked with each other and formed a double helix model. This model was named as the Watson Crick model of DNA in honor of these scientists. The discovery of DNA proved helpful to the field of genetics as it helped in the study of human behavior and also about some rare hereditary diseases.
The DNA also replicates and undergoes transcription. In the DNA transcription process, a DNA structure undergoes protein synthesis and is converted in messenger RNA (mRNA). These messenger RNA are then transcribed into protein molecules. This process leads to gene expression, in which a gene is synthesized to obtain codes. The study of these codes help the researchers in unveiling the mystery surrounding the occurrence of some of the genetic disorders and diseases and to find a cure for them.
There is also another type of DNA, known as mitochondrial DNA, which is present in the mitochondria of a cell. When DNA undergoes mutation and produced mutagens (or defective genes) it can cause numerous health problems which are generally congenital or present at the time of birth. These mutagens can also be transferred from one generation to another.