Deoxyribonucleic acid (DNA) is the hereditary material that is found in humans and other organisms. Each and every cell in a person’s body contains the same DNA. In most cases, DNA is typically located in the cell nucleus where it is referred to as nuclear DNA. Nevertheless, some DNA can be found in mitochondria where they are known as mitochondrial DNA or mtDNA. The core aim of the paper is to expound on how DNA stores and determines the genetic information and how proteins determine the phenotype.
Usually, information that is found in DNA is kept as a code that comprises of chemical bases that include adenine (A), guanine (G), cytosine (C) and thymine (T). The DNA of human beings is made up of three million bases where at least 99% of the bases are similar among all humans. However, the difference between individuals is determined by the sequence or order that is followed in by the bases of each person, an aspect that can be compared to the manner in which different letters of the alphabet can be arranged in myriad ways to form various words. The bases of a DNA pair with each other to come up with units known as base pairs. For instance, base A and T can pair up to firm a base pair (Stegmann 2005, p. 445).
Additionally, each and every base is attached to sugar and a phosphate molecule to form a pair referred to as a nucleotide. Typically, nucleotides have a unique arrangement that embraces two long strands that form a double helix. Thus, the structure of the double helix can be likened to a ladder where the base pairs form the ladders rung’s while the sugar and phosphate molecules create the two vertical pieces of a ladder. It is important to note that DNA has the capability of replicating itself to make identical copies. Each strand that forms the double helix is used as a pattern to duplicate the bases sequence (Stegmann 2005, p. 449).
Phenotypes are visible characteristics of an organism. The Mendel study of organisms mainly embraced the outward observable traits of organisms such as color and height of plants. However, with the help of technology, phenotypes can also encompass inner features. For instance, phenotypes in human beings can include aspects such as skin and eye color. With the technological aid tools, phenotypes can also include elements such as bone density or the type of blood that a person has (Diefenbach, et al 2002, p. 1142).
Proteins are responsible for determining the phenotype since genes control the production of proteins. Virtually, proteins are responsible for all the reactions that occur in a cell, including dictating the appearance of a person/ observable characteristics. Essentially, proteins are responsible for the overall maintenance of cell and other aspects such as the shape and rigidity of tissues. Additionally, some proteins are tasked with the role of communication and moving molecules from one cell to another. A significant number of proteins in the body are enzymes that act as catalysts in various chemical reactions that synthesize and transform biological molecules in the body (Diefenbach, et al 2002, p. 1145).
The phenotype variation between individuals is mainly due to the varying types and quantities of the biological molecules that exist in cells and tissues of an organism. For instance, the difference in the activity of various enzymes can dictate the color of the leaves of a flower. A gentle variation in enzyme’s activity may make a sheet white other than purple. In a similar manner, a slight change in the proteins that are tasked with cell communication may result in a leaf with a different shape as compared to others (Diefenbach, et al 2002, p. 1149).
In a nutshell, proteins play a significant part in determining the phenotype of an organism. The fact that they control the gene control the production of proteins vividly shows that they determine the phenotype. Proteins also direct almost all the activities in a cell including phenotypes. However, other aspects such as mutation can play some role in determining the phenotype.
- Diefenbach, A., Tomasello, E., Lucas, M., Jamieson, A.M., Hsia, J.K., Vivier, E. and Raulet, D.H., 2002. Selective associations with signaling proteins determine stimulatory versus costimulatory activity of NKG2D. Nature immunology, 3(12), pp.1142-1149.
- Stegmann, U.E., 2005. Genetic information as instructional content. Philosophy of Science, 72(3), pp.425-443.