Viral Structure and Life Cycle

A set of 20 vocabulary flashcards covering the structure, replication cycles, and research methods related to viruses and prions based on the lecture notes.

Viruses

Entities that lack metabolic machinery and must infect a host cell to reprogram its metabolic machinery to produce more viruses intracellularly.

Nucleic acid core

The central part of a virus containing genetic material consisting of either DNA or RNA, but never both.

Capsid

A structure composed of capsomere proteins that encases the nucleic acid core and provides protection and shape to the virus.

Envelope

An optional outer layer of a virus, mainly composed of phospholipids and proteins, that originates from the host cell's membrane.

Spikes

Structures responsible for attaching the virus to host cell membrane receptors; these are present on the envelope in enveloped viruses.

Adsorption

The stage of the replication cycle where a virus binds its spikes to matching receptors on the host cell membrane.

Host range

The specific 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 within a host that a virus can infect, such as liver cells or white blood cells.

Endocytosis

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

Membrane fusion

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

Uncoating

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

Synthesis

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

Assembly

The process of putting together mature viruses by forming the capsid around the genetic material.

Cytopathic Effects (CPEs)

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

Proviruses

Viruses like the Varicella zoster virus that establish a latent relationship with the host cell to cause recurrent infections.

Oncoviruses

Mammalian viruses capable of initiating tumors and potentially causing cancer.

Bacteriophages

Viruses that specifically infect and potentially kill bacteria, utilizing lytic or lysogenic life cycles.

Lysogenic conversion

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

Plaque assay

A research method used to observe the degeneration and lysis of infected cells within a cell culture line.

Creutzfeldt-Jakob Disease (CJD)

The human form of spongiform encephalopathy caused by misfolded prion proteins leading to the breakdown of neurons.