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 individual segments of a DNA molecule. Genes are further broken down into smaller, linear building blocks called nucleotides. Nucleotides are aptly named for the nitrogenous base they contain. Much of biology hinges on the chemistry of DNA.
A nucleotide monomer can be chemically broken down into three parts. The first part is a five-carbon sugar, also called a pentose sugar. The second part is a central phosphate atom bonded to a ring of four oxygen atoms, also called a phosphate group. The third part is one nitrogen-containing base from a possible four: Thymine, cytosine, adenine, or guanine.
The four bases, A, C, T, or G, are categorized into two types: Purines and pyrimidines. Purines are chemically a double-ringed structure, whereas pyrimidines form a single ring. Adenine and guanine are classified as purines, while cytosine and thymine are pyrimidines.
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.
Nucleotide bonding between two DNA strands occurs due to weak, but important, hydrogen bonds. The chemical structure of DNA appears twisted due to this and other complex bonding between the various elements in the DNA molecule itself. The twisted ladder shape of DNA is what gives the molecule its unique name - the double helix. - 15437
Genes are individual segments of a DNA molecule. Genes are further broken down into smaller, linear building blocks called nucleotides. Nucleotides are aptly named for the nitrogenous base they contain. Much of biology hinges on the chemistry of DNA.
A nucleotide monomer can be chemically broken down into three parts. The first part is a five-carbon sugar, also called a pentose sugar. The second part is a central phosphate atom bonded to a ring of four oxygen atoms, also called a phosphate group. The third part is one nitrogen-containing base from a possible four: Thymine, cytosine, adenine, or guanine.
The four bases, A, C, T, or G, are categorized into two types: Purines and pyrimidines. Purines are chemically a double-ringed structure, whereas pyrimidines form a single ring. Adenine and guanine are classified as purines, while cytosine and thymine are pyrimidines.
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.
Nucleotide bonding between two DNA strands occurs due to weak, but important, hydrogen bonds. The chemical structure of DNA appears twisted due to this and other complex bonding between the various elements in the DNA molecule itself. The twisted ladder shape of DNA is what gives the molecule its unique name - the double helix. - 15437
About the Author:
RJ Sullivan manages several profitable online businesses and is a accomplished editor and writer. Ms. Sullivan also writes for In the Gno, a blog dedicated to demystifying the science of genetics in an interesting and easy-to-understand manner. Visit In the Gno to learn more about genetics and DNA.
