The four nitrogen bases of DNA pair in specific ways. The nitrogen base adenine pairs with the nitrogen base thymine, and the nitrogen base cytosine pairs with the nitrogen base guanine. Because these bases always pair the same way, the cell is able to make two identical copies of DNA during DNA replication.
DNA is a polymer of nucleotides. A DNA molecule consists of three parts—a nitrogen base, a five-carbon sugar called deoxyribose, and a phosphate group. There are four DNA nucleotides, each with one of the four nitrogen bases (adenine, thymine, cytosine, and guanine). The first letter of each of these four bases is often used to symbolize the respective nucleotide (A for adenine nucleotide, for example)
DNA stands for DeoxyriboNucleic Acid The letters A, G, C, and T represent the four nitrogen bases of DNA. They are adenine, guanine, cytosine, and thymine. Three nitrogen bases make up a codon, which represents a particular amino acid. The sequence of nitrogen bases in DNA specifies the sequence of amino acids in a protein. The shape and function of a protein is determined by the sequence of its amino acids.
DNA is made up of molecules called nucleotides which include a nitrogen base. There are four types of nitrogen bases: adenine (A), thymine (T), guanine (G) and cytosine (C). The order of these bases is what determines DNA's instructions, or genetic code. Genes are made up of DNA, they act as instructions to make molecules called proteins. In humans, genes vary in size from a few hundred DNA bases to more than 2 million bases…