What is DNA
Published 10 Apr 2017
This is an acronym which in full refers to Deoxyribonucleic acid. This is a nucleic acid that is made up of genes which are responsible for the growth and development of all living organisms. It is a hereditary material in all living organisms with the highest concentration being found in the nucleus of a cell. This discussion seeks to find out what DNA is all about and its various functions in the body. DNA consists of four chemical bases namely thymine, guanine, cytosine and adenine. These four chemical bases pair to form what is known as base pairs. In addition each an every one of these bases has a molecule of phosphate and sugar attached to it. A base that has these two attachments is referred to as a nucleotide (Easteal, S. 30-33).
To be able to clearly understand how DNA works it is important to look at some of the properties of DNA. DNA has both physical and chemical properties which influence the manner in which it functions. One of the properties is replication. This means that DNA has the ability to make several copies of itself. This property plays an important role in cell division as the newly formed cell must be exactly like the old one.
As already mentioned DNA exist in pairs as opposed to single molecules. A pair of DNA takes the shape of a helix whose stability is maintained by bonds of hydrogen. Basic pairing is yet another property of DNA. This refers to the pairing a pattern of the DNA. One peculiar thing to note is that the bases are specific in pairing so that they can only pair with certain bases and not others. Cytosine for example only pairs with guanine base and not any other. Adenine on the other hand can only pair with thymine. This is referred to as complementary base pairing (Transnational College, 98-102). Despite being simple a concept complementary base pairing is important in understanding how DNA functions.
The two grooves in the DNA also form part of the properties. These grooves are classified as major and minor groves. These grooves help in the selective passage of only those proteins that are important and it is these proteins that get into contact with the bases. It is extremely important for proteins to get into contact with the bases as some of the proteins known as transcriptional factors play a key role in prevention of deformities. It is these proteins that determine the size of one’s cells and also suppress any emerging tumuor. These proteins also play a contributory role in the general growth and development of organisms. It is also these proteins that enhance communication in human beings. It is due to these grooves that cellular processes take place effectively with the body of a living organism (Transnational College, 89-92).
The strands of DNA are quite long yet they are able to fit well in our cells which in comparison are small. DNA is approximated to be 1.8 metres by length yet it is able to fit in our small body cells. This is because of the super coiling property of DNA. This simply means that the DNA is able to coil itself so that it efficiently uses the small space available in the body cells. The different confirmations in which DNA exists are important in ensuring that the DNA is maintained and repaired incase it is broken. The DNA also has a strand that is an antisense and helps in making of proteins.
Did you know that our characteristics as human beings are by and large influenced by the DNA in our body cells? The colour of your eyes for instance is influenced by the DNA in your body DNA is responsible in ensuring that body cells grow and function in harmony to form an effective body of a living organism. DNA as already mentioned is hereditary. This means that it is passed from one generation to another through family lines. With the help of technology it is now possible to modify the structure of a DNA and also to transfer DNA from one organism to another (Kobilinsky, 72-74).
One of the frequently asked questions as far as DNA is concerned is where DNA is found in the body of living organism. The body is made of millions of cells approximately every 10 billions cells. Inside every cell is a nucleus that contains 46 chromosomes and in turn every chromosome contains a DNA. Thus DNA I contained in the chromosomes that are found in the nucleus of a cell.
DNA is also responsible for the synthesis of Ribonucleic acid (RNA) which is also a nucleic acid that is critical in formation, growth and development of organisms. Alteration of DNA can cause serious health problems. This alteration mainly is done by a substance known as mutagen which is instrumental in causing mutation of genes in both plants and animals (Kobilinsky, 56-60). Mutagen attacks the DNA of an organism and as a result the genetic code of the organism is altered. Common sources of mutagen include x-rays and ultra-violet rays. Other possible damages that occur as a result of mutagenic attack on DNA include damages of the cells.9Easteal, 1991) As a result the DNA is manipulated and ends up reproducing something that is harmful to the organism.
The mutations caused by mutagens usually result to developments of tumors e.g. cancerous tumuor (Calladine, 76-80). In addition mutagens cause birth defects so that a child is born without some vital organs of the body or when some body parts are deformed and cannot function normally. Mutagens usually attack the DNA at the replicating stage. This means that all other replicated DNAs will have this defect and will pass it down to other replicated molecules (James, D. W. & Andrew, B. 89-94).
As already mentioned DNA is contained in every cell of an organism’s body. This means that evidence of one’s identity can be taken from nay part of the body. This is normally important on a number of cases especially when identities of one or more people are in dispute. For instance during paternity test to ascertain whether a particular man is actually the father of an alleged child it is the DNA that helps determine by comparing the composition of the two individuals.
DNA thus plays an important role in the growth and development of living organisms and it is important not to expose oneself to sources of mutagen as they can causes sever damage to the body of an organism.
- Calladine, C. Understanding DNA, London: Academic Press, 2004.
- Easteal, S. DNA Profiling. New York: C.R.C Press, 1991.
- Kobilinsky, L. D.N.A. Washington: John Wiley& Sons, 2004.
- James, D. Watson, & Andrew, Berry. DNA: The Secret of Life. New York:
- John Wiley and Sons, 2004.
- Transnational College. What is DNA, London: SAGE. 2003.