DNA is the hereditary material that contains the genetic instructions to direct protein synthesis. This is another way of saying that DNA is a genetic blueprint. The chemical instructions in DNA are stored in segments called genes.
Genes are smaller segments that, when strung together, comprise a DNA molecule. They are unique linear sequences of nucleotide monomers named for the nitrogenous base they contain. Nucleotide monomers, or nucleotides, are the building blocks of genes. The chemical structure of DNA is important because biology and chemistry are uniquely intertwined.
A nucleotide is a chemical unit that has three main components. The first is a sugar with five carbon atoms, aptly named a five-carbon sugar or pentose sugar. The second is a phosphate atom bonded to four oxygen atoms, called a phosphate group. The third is one of four possible nitrogen-containing bases called A for adenine, C for cytosine, T for thymine, or G for guanine.
The four nitrogen-containing bases are sometimes represented as T, C, A, or G, and are always from of one of two chemical categories: Purines or pyrimidines. Purines form a double-ring, while pyrimidines are chemically a single ring. Guanine and adenine are classified as purines, whereas the pyrimidines are thymine and cytosine.
The chemistry of DNA hinges on precise bonding between pyrimidines and purines. This unique bonding pattern is what unites two DNA strands together. The structure formed from these precise chemical interactions is termed a double helix.
The twisted shape of DNA is what led researches to coin the term double helix. A molecule of DNA is two single strands joined together by hydrogen bonds. A single strand of DNA is likened to a ladder that has been cut down the middle, resulting in two halves.
One strand complements the other in a way that is also related to chemical structure. The component nucleotides make the rungs of the ladder. The nucleotides in the first strand of DNA, the left side of the ladder, pair with nucleotides in the second DNA strand or the right side of the ladder. Together, the two DNA strands unite to form what looks like one single ladder.
Properly-functioning genes require the correct pairing of nucleotides. This pairing is based on a strict set of base-pair rules pioneered by James Watson and Francis Crick. Base-pair rules dictate the union of a purine to a pyrimidine. This results in only possible pairings of A with T and C with G.
The hydrogen bonds formed between nucleotide pairs are important to the structure of DNA. These weak bonds, along with complex bonding among other molecular elements are what give DNA its twisted appearance. This particular shape is why DNA is aptly named a double helix. - 17995
Genes are smaller segments that, when strung together, comprise a DNA molecule. They are unique linear sequences of nucleotide monomers named for the nitrogenous base they contain. Nucleotide monomers, or nucleotides, are the building blocks of genes. The chemical structure of DNA is important because biology and chemistry are uniquely intertwined.
A nucleotide is a chemical unit that has three main components. The first is a sugar with five carbon atoms, aptly named a five-carbon sugar or pentose sugar. The second is a phosphate atom bonded to four oxygen atoms, called a phosphate group. The third is one of four possible nitrogen-containing bases called A for adenine, C for cytosine, T for thymine, or G for guanine.
The four nitrogen-containing bases are sometimes represented as T, C, A, or G, and are always from of one of two chemical categories: Purines or pyrimidines. Purines form a double-ring, while pyrimidines are chemically a single ring. Guanine and adenine are classified as purines, whereas the pyrimidines are thymine and cytosine.
The chemistry of DNA hinges on precise bonding between pyrimidines and purines. This unique bonding pattern is what unites two DNA strands together. The structure formed from these precise chemical interactions is termed a double helix.
The twisted shape of DNA is what led researches to coin the term double helix. A molecule of DNA is two single strands joined together by hydrogen bonds. A single strand of DNA is likened to a ladder that has been cut down the middle, resulting in two halves.
One strand complements the other in a way that is also related to chemical structure. The component nucleotides make the rungs of the ladder. The nucleotides in the first strand of DNA, the left side of the ladder, pair with nucleotides in the second DNA strand or the right side of the ladder. Together, the two DNA strands unite to form what looks like one single ladder.
Properly-functioning genes require the correct pairing of nucleotides. This pairing is based on a strict set of base-pair rules pioneered by James Watson and Francis Crick. Base-pair rules dictate the union of a purine to a pyrimidine. This results in only possible pairings of A with T and C with G.
The hydrogen bonds formed between nucleotide pairs are important to the structure of DNA. These weak bonds, along with complex bonding among other molecular elements are what give DNA its twisted appearance. This particular shape is why DNA is aptly named a double helix. - 17995
About the Author:
RJ Sullivan manages several successful online businesses and is a accomplished editor and writer. Ms. Sullivan also writes for In the Gno, a blog dedicated to presenting the science of genetics in an interesting and easy-to-understand manner. Visit In the Gno to learn more about genetics and DNA.
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