Biology Chapter 18 Flashcards
Viruses
Non-living particles with nucleic acid genomes.
Nonliving
Don’t use energy, carry out metabolism, maintain homeostasis, or reproduce by themselves.
Virus
A small infection particle that consists of nucleic acid enclosed in a protein coat.
Host cell
A cell that is infected by a virus.
Host species
A species that can be infected by a specific virus.
Host range
The number of species and cell types a virus can infect.
Capsid
Protein coat of virus, enclosing a genome with one or more molecules of nucleic acid (DNA or RNA).
Viral envelope
Lipid bilayer of a virus that is derived from a cellular membrane from the host cell and is embedded with virally encoded spike glycoproteins.
Viral genome
Genetic material in a virus. RNA or DNA.
Bacteriophages
Viruses that infect bacteria. (phages)
Single stranded and double stranded
Some viruses have single stranded and others have double stranded.
Viral reproductive cycle
Series of steps leading to the production of new viruses.
Integrase
Enzyme made by a gene carried y viruses that are capable of integration.
Prophage
Phage DNA in a bacterium after integration.
Lysogenic cycle
Viral reproductive cycle while virus exists as a prophage.
Reverse transcriptase
Enzyme that copies RNA into DNA. (HIV)
Provirus
Integrated viral DNA in a eukaryotic cell. Retroviruses.
Lytic cycle
Steps 1, 2, 4, 5, and 6 lead to cell lysis.
Viruses can integrate what?
Their genomes into a host chromosome.
Latent
Inactive
Temperate phages
Bacteriophages that can alternate between lysogenic and lytic cycles.
Virulent phages
Only have lytic cycles.