Bacteriophages and Viral Replication

Comprehensive vocabulary flashcards covering bacteriophage anatomy, infection mechanisms, viral replication pathways (lytic and lysogenic cycles), and related microbiological terms.

Bacteriophage (Phage)

A virus that specifically infects bacteria.

Capsid (Head)

The protective covering for the viral genetic material that contains and protects the viral genome (DNA or RNA) and has an icosahedral shape with $20$ sides.

Collar

The structural component that connects and separates the icosahedral head from the tail region of a bacteriophage.

Tail

A helical structure containing a hollow channel that penetrates the bacterial cell wall and provides a pathway for the viral genetic material to enter the host cytoplasm.

Base Plate

The structure located at the end of the tail, associated with the tail fibers, that helps anchor the bacteriophage to the bacterial cell during infection.

Tail Fibers

Fibrous extensions resembling legs that recognize, attach to, and bind the surface of the bacterial host cell to mediate initial attachment.

Obligate Intracellular Parasites

Organisms or biological agents, such as viruses, that cannot independently reproduce outside a host and can only replicate inside a living host cell.

Co-Culturing

The process in which researchers combine and grow a virus alongside its appropriate living host cells in order to propagate the virus.

Lysis

The rupturing and destruction of the host bacterial cell, resulting in cell death and the release of progeny viruses.

Progeny Viruses

New viral particles that are produced inside the host cell and released into the surrounding environment upon host cell lysis.

Lytic Cycle

A viral replication pathway in which the virus actively replicates inside the bacterial host, producing new viral particles and destroying the host cell via lysis.

Lysogenic Cycle (Temperate Cycle)

A viral replication pathway in which the viral genome integrates into the bacterial host's genome and remains dormant without immediately destroying the host cell.

Prophage

The viral genetic material after it has integrated into the bacterial host's genome.

Lysogenic Phage (Temperate Phage)

A bacteriophage capable of entering a dormant state within its bacterial host by integrating its DNA into the host genome.

Dormancy

A period during the lysogenic cycle when the viral genome remains part of the bacterial DNA and is not actively producing new viral particles due to suppressed viral protein production.

Reactivation

The process triggered by external stress conditions where an integrated prophage becomes active, begins producing viral proteins, and enters the lytic cycle.

Viral Titer

The quantitative amount or concentration of virus present in a given culture or sample.

Turbidity

The cloudiness or opacity of a liquid culture, which reflects the number of intact bacterial cells suspended in the medium.