T4 bacteriophage

Definition

The T4 bacteriophage is a type of virus that specifically infects bacteria, particularly Escherichia coli (E. coli). It is a double-stranded DNA virus and serves as a model organism in molecular biology for understanding viral replication and interactions with host cells.

5 Must Know Facts For Your Next Test

1. T4 bacteriophage has a complex structure featuring an icosahedral head, a cylindrical neck, and tail fibers that help it attach to bacterial cells.
2. The T4 phage utilizes a lytic life cycle, meaning it quickly takes over the host cell's machinery to replicate itself and causes the host to burst, releasing new phages.
3. The genome of T4 bacteriophage consists of approximately 169 kb of double-stranded DNA, which encodes around 300 genes.
4. T4 is well-studied due to its relatively simple yet effective method of infection, making it a vital tool for genetic engineering and phage therapy research.
5. Phage therapy utilizing T4 bacteriophage has been investigated as an alternative treatment for antibiotic-resistant bacterial infections.

Review Questions

• How does the T4 bacteriophage's structure contribute to its ability to infect bacterial cells?
  • The T4 bacteriophage has a unique structure that includes an icosahedral head and tail fibers that allow it to effectively attach to specific receptor sites on the bacterial surface. This attachment is crucial because it enables the phage to inject its genetic material into the host cell. The efficiency of this process is enhanced by the T4's precise targeting of E. coli, allowing it to successfully initiate infection and enter the lytic cycle.
• Discuss the implications of using T4 bacteriophage in phage therapy for treating bacterial infections.
  • T4 bacteriophage presents promising implications for phage therapy due to its specificity in targeting E. coli. As antibiotic resistance becomes more prevalent, utilizing phages like T4 offers a potential solution by selectively infecting and destroying pathogenic bacteria without harming beneficial microbiota. The ability of T4 to replicate rapidly within its bacterial hosts further supports its application in treating infections where antibiotics fail.
• Evaluate the significance of studying T4 bacteriophage in molecular biology and its impact on our understanding of viral behaviors.
  • Studying T4 bacteriophage has been significant in molecular biology because it provides insights into viral replication mechanisms and host interactions. This understanding has advanced genetic engineering techniques, enabling scientists to manipulate DNA for various applications, including gene therapy. Additionally, research on T4 has laid the groundwork for exploring the dynamics between viruses and their hosts, informing strategies for combating viral infections and understanding the evolution of viruses.

Related terms

Lytic Cycle: The lytic cycle is the process by which a virus infects a host cell, replicates its genetic material, assembles new virions, and ultimately causes the cell to lyse, releasing the newly formed viruses.

Bacteriophage: Bacteriophages are viruses that infect bacteria, utilizing bacterial machinery for replication. They are diverse in structure and function, including both lytic and lysogenic cycles.

Host Cell: A host cell is a living cell that a virus infects in order to replicate its genetic material and produce new viral particles.