Chapter 6: Viruses, Viroids, & Prions Part I

These flashcards cover the key concepts related to viruses, their structure, classification, and ecological roles based on the lecture notes.

Virus

An acellular entity that requires a host cell to reproduce and is composed of nucleic acid enclosed in a protein capsid.

Capsid

The protein shell that encases the viral genome, consisting of repeating subunits called capsomeres.

Virion

A complete viral particle that consists of a viral genome surrounded by a protein coat.

Obligate intracellular parasite

An organism that can only reproduce inside the cells of a host.

Host range

The spectrum of host cells that a virus can infect.

Baltimore classification

A system used to classify viruses based on their type of genome and method of mRNA synthesis.

Viral infectivity

The capacity of a virus to infect a host cell and reproduce.

Viroid

A small, circular RNA molecule that infects plants and lacks a protein coat.

Prion

A misfolded protein that can induce other normal proteins to also misfold, often leading to disease.

Viral shunt

A phenomenon where viral infection leads to the decomposition of infected hosts, recycling nutrients in an ecosystem.

Tropism

The specificity of a virus for a particular host tissue or cell type.

RNA-dependent RNA polymerase (RDRP)

An enzyme that synthesizes RNA from an RNA template, essential for the replication of certain viruses.

Naked virus

A virus that lacks an envelope, consisting only of a capsid and nucleic acid.

Enveloped virus

A virus that has an outer lipid membrane derived from the host cell, surrounding its capsid.

Symmetrical viruses

Viruses with a consistent, regular structure, including icosahedral and filamentous capsids.

Asymmetrical viruses

Viruses that exhibit irregular shapes and lack a symmetrical capsid structure.