Genetics is the study of heredity and the processes of inheritance. Since Gregor Mendel's pea-plant experiments, genetic research and the study of DNA has fascinated many in the scientific community. Biologists work to discover how organisms grow and develop. The public's interest in genetics is also present and can be seen throughout popular culture, especially in the form of science fiction. Familiar storylines include a scientist that recreates prehistoric creatures from a piece of DNA or has built a hideous monster using genetic experimentation. Although these stories are for entertainment, they still relate to the principles of genetics. What role does DNA play in the study of genetics? One way genetic information is stored is in deoxyribonucleic acid, or DNA, molecules. DNA serves as the master plan for the genetic makeup of an organism. In this lesson, you will learn how DNA is copied and used to transfer genetic information. You will also learn how the genetic information in DNA results in gene expression.
Molecular biology is the study of molecules that are related to the field of biology. The study includes proteins, enzymes, and DNA, all of which are genetic material. Molecular biologists are interested in the role that genetic material plays in the creation and function of individual cells and complex organisms. To understand how genetic material influences the functions of cells, biologists first had to identify the components of genetic material. DNA: The Building Blocks of Life
Although there are several factors that influence gene expression, DNA is the main molecule that stores genetic information for an organism. DNA is a type of nucleic acid. A nucleic acid is a type of molecule that stores genetic information. DNA is a polymer, or a large molecule that is made up of smaller molecules. These smaller molecules contain the genetic information needed for the creation of proteins. All organisms are made of proteins and need protein enzymes to function. These organic compounds constitute a large percentage of matter within all organisms. Given that proteins are responsible for the majority of chemical reactions within the body, it is essential to know how they are produced. The molecules that make up DNA are responsible for storing all the needed genetic information for the formation of proteins. In addition, DNA can be replicated, or copied. This unique feature allows copies of DNA to be passed on during cell division and reproduction. How does DNA form proteins and replicate? DNA Structure
DNA is made up of smaller, base unit molecules that connect to form a larger, longer strand. These base unit molecules are called nucleotides. Nucleotides are the basic unit of nucleic acid and each nucleotide is made of three different components: a phosphate group, a simple sugar, and a nitrogen base.
The three parts of a nucleotide in DNA
Although both the phosphate group and the deoxyribose sugar have the same chemical composition in each nucleotide, there are four different types of nitrogen bases. The four nitrogen bases are: thymine (T), cytosine (C), adenine (A) and guanine (G). The variation of nitrogen bases produces four types of nucleotides in DNA.
The four types of nitrogen bases found in DNA
Adenine (A), guanine (G), cytosine (C), and thymine (T) are the base components that form all DNA found on Earth. These four nucleotides provide the framework for the vast genetic variation that is found among Earth's life forms. The Double Helix
A strand of DNA is formed by the chemical bonds, or connections, between nucleotides.Nucleotides attach together forming long chains, as seen in the diagram. The shape of DNA, made from the two connected strands, is called a double helix. A helix is twisted or coiled shape. Therefore, because DNA is made of a double strand of twi...