Watson-crick model

Definition

The Watson-Crick model describes the double helical structure of DNA, proposing that it consists of two complementary strands wound around each other, with specific base pairing between adenine and thymine, and guanine and cytosine. This model is fundamental in understanding how genetic information is stored, replicated, and expressed in living organisms.

5 Must Know Facts For Your Next Test

1. The Watson-Crick model was first published in 1953 by James Watson and Francis Crick, providing a comprehensive explanation of DNA's structure.
2. The double helix formation is stabilized by hydrogen bonds between complementary base pairs and hydrophobic interactions between the bases.
3. Each complete turn of the helix contains about 10 base pairs, giving DNA a uniform diameter.
4. The model also explains how genetic information can be accurately copied during DNA replication, as each strand serves as a template for creating a new complementary strand.
5. The discovery of the Watson-Crick model was pivotal for molecular biology, influencing fields like genetics, biotechnology, and forensic science.

Review Questions

• How does the Watson-Crick model explain the mechanism of DNA replication?
  • The Watson-Crick model illustrates that DNA consists of two complementary strands, allowing each strand to serve as a template during replication. When DNA replicates, the hydrogen bonds between base pairs break, and each single strand guides the synthesis of a new complementary strand. This ensures that the genetic information is accurately copied, maintaining the integrity of the genetic code across generations.
• In what ways does the structure proposed by the Watson-Crick model contribute to the stability and functionality of DNA?
  • The structure outlined by the Watson-Crick model contributes to DNA's stability through hydrogen bonding between base pairs and stacking interactions among bases. The double helix configuration protects the genetic material from damage and enables efficient packing within cells. This arrangement also facilitates vital processes like transcription and replication by ensuring that specific sequences can be accessed when needed while maintaining overall structural integrity.
• Evaluate the impact of the Watson-Crick model on our understanding of genetics and molecular biology in contemporary research.
  • The Watson-Crick model revolutionized our understanding of genetics and molecular biology by providing insights into how DNA functions as hereditary material. Its implications extend to various fields such as genetic engineering, where knowledge of DNA structure allows scientists to manipulate genes for therapeutic purposes. Moreover, this foundational model has paved the way for advancements in biotechnology, including CRISPR technology, which enables precise editing of genetic sequences. Overall, its influence continues to shape research methodologies and applications in modern science.

Related terms

DNA: Deoxyribonucleic acid, the molecule that carries genetic information in living organisms.

Base Pairing: The specific pairing of nitrogenous bases in DNA, where adenine pairs with thymine and guanine pairs with cytosine.

Antiparallel Strands: Refers to the orientation of the two DNA strands in the double helix, where one strand runs in the 5' to 3' direction and the other runs in the 3' to 5' direction.