Science
DNA and the Genetic Code
From Wikipedia Clone, the free encyclopedia
Deoxyribonucleic acid (DNA) is the molecule that carries the genetic instructions for the development, functioning, growth, and reproduction of all known living organisms and many viruses.
Structure:
DNA is a double helix formed by two strands running in opposite directions. Each strand is composed of nucleotide subunits, each containing:
- A phosphate group
- A deoxyribose sugar
- One of four nitrogenous bases: Adenine (A), Thymine (T), Guanine (G), or Cytosine (C)
Base pairing rules: A always pairs with T, and G always pairs with C. This complementary pairing is the basis for DNA replication and protein synthesis.
The Genetic Code:
Genes are segments of DNA that encode for proteins. The sequence of bases acts as a blueprint — sets of three bases (codons) correspond to specific amino acids that are assembled into proteins in a process called translation.
Discovery:
James Watson and Francis Crick, building on X-ray crystallography data by Rosalind Franklin, proposed the double helix structure of DNA in 1953.
Applications:
- Genetic engineering and GMO crops
- DNA fingerprinting in forensics
- Gene therapy for inherited diseases
- The Human Genome Project (completed 2003), which mapped all ~3 billion base pairs in human DNA
Structure:
DNA is a double helix formed by two strands running in opposite directions. Each strand is composed of nucleotide subunits, each containing:
- A phosphate group
- A deoxyribose sugar
- One of four nitrogenous bases: Adenine (A), Thymine (T), Guanine (G), or Cytosine (C)
Base pairing rules: A always pairs with T, and G always pairs with C. This complementary pairing is the basis for DNA replication and protein synthesis.
The Genetic Code:
Genes are segments of DNA that encode for proteins. The sequence of bases acts as a blueprint — sets of three bases (codons) correspond to specific amino acids that are assembled into proteins in a process called translation.
Discovery:
James Watson and Francis Crick, building on X-ray crystallography data by Rosalind Franklin, proposed the double helix structure of DNA in 1953.
Applications:
- Genetic engineering and GMO crops
- DNA fingerprinting in forensics
- Gene therapy for inherited diseases
- The Human Genome Project (completed 2003), which mapped all ~3 billion base pairs in human DNA
References
1. Watson, J.D. & Crick, F.H.C. (1953). Molecular Structure of Nucleic Acids. Nature.
2. NCBI National Human Genome Research Institute. (2022). DNA Fact Sheet.