Viral Structure and Life Cycle Practice Flashcards

A set of vocabulary flashcards covering viral structure, animal virus replication, bacteriophages, and related pathological agents based on the lecture notes.

Viruses

Infectious agents that lack metabolic machinery and must reprogram a host cell to produce more viruses intracellularly.

Nucleic acid core

The component of a virus that contains the genetic material, consisting of either DNA or RNA, but never both.

Capsid

A protective shell composed of capsomere proteins that encases the nucleic acid core and provides the virus its shape.

Envelope

An optional layer originating from the host cell membrane, mainly composed of phospholipids and proteins, present in enveloped viruses.

Spikes

Structures responsible for attaching the virus to specific receptors on the host cell membrane.

Adsorption

The stage where the virus binds its spikes to the host’s cell membrane receptors in a highly specific process.

Host range

The spectrum of hosts, such as human, swine, or avian, that a virus is capable of infecting.

Viral Specificity

The specific kinds of cells or tissues a virus can infect within a specific host, such as liver or respiratory cells.

Endocytosis

A penetration method where the host cell is tricked into engulfing the entire virus through its cell membrane.

Membrane fusion

An entry method used only by enveloped viruses where the envelope merges directly with the cell membrane to free the nucleocapsid.

Uncoating

The process after penetration where host cell digestive enzymes release the viral genetic material into the cytoplasm.

Synthesis

The replication stage where the virus manipulates the host cell to produce viral DNA/RNA and viral proteins.

Budding

The process by which enveloped viruses are released, where the nucleocapsid binds to the membrane and pinches off a pouch.

Cytopathic Effects (CPEs)

Virus-induced damage to the cell that alters its microscopic appearance.

Proviruses

Viruses, such as Herpes or Varicella zoster, that establish a latent relationship with the host cell to cause recurrent infections.

Oncoviruses

Mammalian viruses capable of initiating tumors and therefore causing cancer.

Bacteriophages

Viruses that infect and potentially kill bacteria, following either a lytic or lysogenic life cycle.

Lysogenic conversion

When a bacterium acquires a new trait, such as antibiotic resistance or toxin production, from its temperate phage.

Plaque assay

A technique used in cell cultures to observe the degeneration and lysis of infected cells.

Prions

Misfolded proteins that induce other brain proteins to misfold, leading to spongiform encephalopathies like Creutzfeldt-Jakob Disease (CJD).