Chapter 5

the human virome is

entire population of viruses present in and on human body

viral spikes

found on both enveloped and naked viruses, they mediate the docking process of virus to host cell, consist of proteins and carbohydrates, coded for by the viral genome

lytic

host bacteria are lysed and killed by the infection

cytopathic effects in virally infected animal cells

inclusion bodies and syncytia

T-even phages

infect Escherichia coli cells

When phage nucleic acid is incorporated into the nucleic acid of its host cell and is replicated when the host DNA is replicated, this is considered part of which cycle?

lysogenic cycle

TRUE OR FALSE all viruses lack the machinery to synthesize proteins

true

the process of ____ occurs when viruses lose their capsid (and envelope, if they have one) during or after penetration into a host cell

uncoating

order of viral life cycle

8-36 hours 1. Absorption (attachment to receptors present on the host cell; uses viral attachment proteins; host range = cells that the virus can infect; tropisms = specificities of viruses for certain tissues) 2. Penetration (through endocytosis or direct fusion - only envelope viruses) 3. Uncoating (opening of the protein capsid and releasing of nucleic acid into the cytoplasm) 4. Synthesis (nucleic acids, capsid, and proteins) 5. Assembly (all viruses self assemble) 6. Release (naked - lyse the cell; enveloped - lyse or bud)

characteristics exhibited Viral capsids

Composed entirely of protein May be an icosahedral shape May be helical in shape Protect the viral nucleic acid Composed of subunits called capsomers May bind to the surface of the host cell

TRUE or FALSE Viruses can contain either DNA or RNA, but not both

True

prion

abnormal protein fibrils

It is well known that ___ have no effect on treating viral infections

antibiotics

which of the following describes the various viral "parts" coming together to produce virus particles?

assembly

Any virus that specifically infects bacteria is called

bacteriophage

A viral infection in which the virus can remain latent in the host cell for weeks to years is described as a(n) _________ infection, and may lead to cancer if host DNA is altered

persistent

What cellular organisms can viruses infect?

plants, bacteria, animals, fungi, protozoa

Phage DNA that is integrated into the bacterial host genome is called a

prophage

capsomer

protein subunit that forms the viral capsid

At minimum, all viruses are composed of

proteins and nucleic acids

An enzyme capable of taking an RNA genome and generating a DNA copy is called

reverse transcriptase

a nonceullular infectious agent that depends on other viruses for replication is known as a(n) virus

satellite

what name is given to a phage "type" which can incorporate itself into the host genome as a lysogenic prophage

temperate