Virus Structure - Part I
This protein coat surrounds and protects a viral genome.
What is the capsid?
This lipid-containing outer covering surrounds the capsid of some viruses.
What is an envelope?
During this first stage, viral attachment proteins bind to matching host-cell receptors.
What is attachment or adsorption?
This bacteriophage cycle produces new viruses and ends with rupture of the bacterial cell.
What is the lytic cycle?
This type of virus most commonly causes oral cold sores, although it can also cause genital herpes.
What is herpes simplex virus-1 (HSV-1)?
A viral genome and its surrounding capsid together form this structure.
What is a nucleocapsid?
This release process allows many viruses to acquire an envelope from a host-cell membrane.
What is budding?
During this stage, a virus enters the host cell, sometimes through endocytosis or membrane fusion.
What is penetration or entry?
During the lysogenic cycle, this forms when the bacteriophage inserts its DNA into the bacterial chromosome.
What is a prophage?
This type of virus most commonly causes genital herpes and establishes lifelong latency in sensory neurons.
What is herpes simplex virus-2 (HSV-2)?
These viral surface proteins bind to specific receptors on host cells.
What are glycoproteins or spikes?
These viruses lack a lipid envelope.
What is a nonenveloped or naked virus?
During this stage, the viral genome is released from its protective covering inside the host cell.
What is uncoating?
During this replication cycle, temperate phage DNA inserts its genome into bacterial DNA and is copied as the bacterium reproduces.
What is lysogeny?
Certain high-risk types of this nonenveloped DNA virus can cause cervical and other cancers; other types cause warts.
What is human papillomavirus (HPV)?
This term describes a complete infectious viral particle outside a host cell.
What is a virion?
Glycoproteins found on viral capsids or envelopes give viruses this trait AND helps viruses perform this essential first step in infection.
What is specificity AND what is attachment to specific receptors on a host cell?
During this stage, newly made viral genomes and structural proteins are put together into new particles.
What is assembly?
Retroviruses use this type of enzyme to produce a provirus during animal virus replication?
What is reverse transcriptase?
This enveloped retrovirus infects CD4-positive immune cells and can lead to AIDS without effective treatment.
What is human immunodeficiency virus (HIV)?
Viral genomes consist of which of the following?
What is DNA or RNA?
Enveloped viruses can cause these long-lasting infections, sometimes releasing new virions by budding without immediately killing the host cell.
What are persistent infections?
Name the six major stages of animal virus replication in order.
What are attachment (adsorption), penetration (entry), uncoating, synthesis, assembly, and release?
This term describes viral DNA that is permanently integrated into a host cell’s chromosome, as occurs during HIV infection.
What is a provirus?
This herpesvirus causes chickenpox during primary infection and shingles after reactivation.
What is varicella-zoster virus or VZV?