DNA: Difference between revisions
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DNA is composed of 4 [[Base|bases]]; the purines: [[Adenine|Adenine]] (A) and [[Thymine|Thymine]] (T) and the pyrimidines: [[Guanine|Guanine]] (G) and [[Cytosine|Cytosine]] (C). These form complementary bases pairs of AT and GC. DNA also contains a [[Phosphates|phosphate]] group connected to a [[Deoxyribose sugar|deoxyribose sugar]]. | DNA is composed of 4 [[Base|bases]]; the purines: [[Adenine|Adenine]] (A) and [[Thymine|Thymine]] (T) and the pyrimidines: [[Guanine|Guanine]] (G) and [[Cytosine|Cytosine]] (C). These form complementary bases pairs of AT and GC. DNA also contains a [[Phosphates|phosphate]] group connected to a [[Deoxyribose sugar|deoxyribose sugar]]. | ||
<u>Structure of DNA | '''<u>Structure of DNA</u>''' | ||
DNA strands are primarily composed of three repeating units: | |||
*Deoxyribose sugar - | |||
*Phosphate group | |||
*A base | |||
The complementary base pairs in DNA interact with one another via Hydrogen Bonds:<br>• A-T interactions consist of 2 intermolecular Hydrogen bonds <br>• G-C interactions consist of 3 intermolecular Hydrogen bonds <br>These interactions form bridges between two DNA chains, thus creating a double stranded 'ladder' shaped structure. | |||
Revision as of 19:00, 21 November 2010
DNA (deoxyribonucleic acid) is the genetic information found in the nuclei of most organisms. It is arranged into structures called chromosomes. The structure of DNA was identified as being a 'double-helix' by Watson and Crick in 1953.
DNA is composed of 4 bases; the purines: Adenine (A) and Thymine (T) and the pyrimidines: Guanine (G) and Cytosine (C). These form complementary bases pairs of AT and GC. DNA also contains a phosphate group connected to a deoxyribose sugar.
Structure of DNA
DNA strands are primarily composed of three repeating units:
- Deoxyribose sugar -
- Phosphate group
- A base
The complementary base pairs in DNA interact with one another via Hydrogen Bonds:
• A-T interactions consist of 2 intermolecular Hydrogen bonds
• G-C interactions consist of 3 intermolecular Hydrogen bonds
These interactions form bridges between two DNA chains, thus creating a double stranded 'ladder' shaped structure.