T4 Phage

Definition

T4 phage is a type of bacteriophage, a virus that infects and replicates within bacterial cells. It is a lytic phage, meaning it lyses or breaks open the host cell to release new viral particles. T4 phage is a widely studied model organism for understanding viral life cycles and host-virus interactions.

5 Must Know Facts For Your Next Test

1. T4 phage is a member of the Myoviridae family of bacteriophages, which are characterized by their contractile tails.
2. The T4 phage genome is a linear, double-stranded DNA molecule containing approximately 169,000 base pairs.
3. T4 phage uses its tail fibers to attach to the outer membrane of the host bacteria, typically Escherichia coli (E. coli), and injects its genetic material into the cell.
4. Once inside the host cell, the T4 phage hijacks the cellular machinery to replicate its own genetic material and produce new viral particles.
5. The lytic cycle of T4 phage results in the host cell's lysis or bursting, releasing hundreds of new phage particles that can go on to infect other bacterial cells.

Review Questions

• Describe the key features of the T4 phage that allow it to infect and replicate within bacterial cells.
  • The T4 phage is equipped with specialized tail fibers that bind to specific receptors on the surface of the host bacterial cell, typically E. coli. This binding initiates the infection process, allowing the phage to inject its genetic material into the host cell. Once inside, the T4 phage hijacks the cellular machinery to replicate its own DNA and produce new viral particles. The lytic cycle of the T4 phage ultimately results in the host cell's lysis or bursting, releasing hundreds of new phage particles that can go on to infect other bacterial cells.
• Explain the role of the T4 phage in the context of the viral life cycle.
  • The T4 phage is a model organism for understanding the lytic viral life cycle. After attaching to the host bacterial cell and injecting its genetic material, the T4 phage takes control of the cell's resources to replicate its own DNA and produce new viral particles. This process culminates in the host cell's lysis, releasing the newly formed phage particles that can then go on to infect other bacterial cells. The T4 phage's lytic life cycle is a key example of how viruses can exploit host cells to propagate and spread within a population of susceptible hosts.
• Analyze the significance of the T4 phage in the study of viruses and their interactions with host cells.
  • The T4 phage is a widely studied model organism in the field of virology due to its well-characterized lytic life cycle and the ease with which it can be cultured and manipulated in the laboratory. By understanding the mechanisms by which the T4 phage infects, replicates within, and ultimately lyses its host bacterial cells, researchers have gained valuable insights into the fundamental processes of viral infection, replication, and host-virus interactions. These insights have broader implications for our understanding of viral pathogenesis, the evolution of viruses, and the potential applications of phages in areas such as phage therapy and biotechnology.

Related terms

Bacteriophage: A virus that infects and replicates within bacterial cells, also known as a phage.

Lytic Cycle: The viral life cycle in which the virus replicates inside the host cell and causes the cell to lyse or burst open, releasing new viral particles.

Tail Fibers: Specialized proteins on the surface of T4 phage that bind to specific receptors on the host bacterial cell, initiating the infection process.