question

Obligate intracellular parasite

answer

Organisms that MUST use a cell to replicate. Includes: viruses, chlamydias, rickettsias

question

Capsid

answer

A viral component made of protein and that surrounds the virus' nucleic acid.

question

Envelope

answer

A membrane that surrounds some viruses made of lipid bilayer.

question

Virion

answer

A complete virus particle, which includes an envelope, if it has one.

question

Genome

answer

Genetic information

question

Capsomeres

answer

Protein subunits that are part of the protein capsid that surrounds a virus.

question

Enveloped viruses

answer

Viruses that have a bilayer membrane outside their capsids. Viruses that have no bilayer membrane are "naked".

question

Nucleocapsid

answer

Comprises the viral genome together with its capsid.

question

^Naked

answer

A virus with only a nucleocapsid but no envelope, or non-enveloped viruses

question

Glycoproteins

answer

The substance that makes up the spikes that are projections found on the envelopes of certain enveloped viruses.

question

Spikes

answer

Projections on the envelope of certain enveloped viruses. Certain spiked viruses cause RBCs to clump. Useful in virus identification.

question

Complex viruses

answer

Viruses with more elaborate coats or capsids.

question

Bacteriophages

answer

Viruses that infect bacterial cells. They have specialized heads, tails, and tail fibers. The tail fibers are the spikes that the virus uses to attach to the host bacterium.

question

Host range

answer

The spectrum of hosts that a virus can infect.

question

Viral specificity

answer

Refers to the specific type of cells that a virus can infect.

question

Positive (+) sense RNA

answer

One of two types of single-stranded RNA viruses. Positive sense RNA acts like mRNA and can be translated by the host's ribosomes.

question

Negative (-) sense RNA

answer

One of two types of single-stranded RNA. Negative sense RNA acts as a template during transcription to make a positive (+) sense RNA (acts like mRNA) AFTER a host cell has been entered. From there it can be translated by host ribosomes just like positive (+) sense RNA can.

question

Enteroviruses

answer

entero, Greek for "intestine", are viruses that can live in the intestine of the host.

question

Hepatoviruses

answer

hepato, Greek for "liver", viruses that infect the liver.

question

Rhinoviruses

answer

rhino, Greek for "nose", is one genera of viruses responsible for the common cold.

question

Reverse transcriptase

answer

The enzyme used by retroviruses to do reverse transcription where they use their RNA to make dsDNA. It's called reverse transcription because it is the reverse of the typical transcription step where normally DNA -; RNA in protein synthesis.

question

Retroviruses

answer

Enveloped viruses that have two complete copies of (+) sense RNA with which they can do reverse transcription.

question

Provirus

answer

Viral DNA that has been incorporated into the chromosomes of the host DNA.

question

togaviruses

answer

small, enveloped, polyhedral, (+) sense RNA viruses that multiply in the cytoplasm of many mammalian and arthropod host cells.

question

Flaviviruses

answer

Enveloped, polyhedral, (+) sense RNA viruses that are transmitted by mosquitoes and ticks.

question

paramyxoviruses

answer

medium-sized, enveloped, (-) sense RNA viruses with a helical nucleocapsid.

question

Rhabdoviruses

answer

medium-sized, enveloped viruses, whose capsids are helical and so are rod or bullet shaped.

question

orthomyxoviruses

answer

medium sized, enveloped, (-) sense RNA viruses that vary in shape and whose genome is segmented into eight pieces. i.e. influenza virus A.

question

filoviruses

answer

Enveloped, filamentous, single (-) sense RNA viruses that can be transmitted from person to person by close contact with blood, semen, and other secretions and by contaminated needles. I.e. ebola.

question

Bunyaviruses

answer

Enveloped, (-) sense RNA viruses whose genome has three segments. Transmitted by arthropods.

question

Arenaviruses

answer

Enveloped, (-) sense RNA viruses, but their genome has two segments. Carried by rodents. Passed among humans via aerosols or exposure to rat bites or excrement.

question

Reoviruses

answer

naked, polyhedral capsid, medium-sized dsRNA viruses that replicate in the cytoplasm and form distinctive inclusions that stain with eosin. Includes: orthoreoviruses, orbiviruses, rotaviruses.

question

Adenoviruses

answer

Medium-sized, naked, viruses with linear dsDNA that are resistant to chemical agents and are stable from pH 5 to 9 and from 36 degrees celsius and 47 degrees celsius

question

Herpesviruses

answer

herpes, Greek for "creeping", relatively large, enveloped viruses with linear dsDNA that cause a broad spectrum of diseases. Tendency to go latent between relapses.

question

Latency

answer

The ability of viruses, like the herpes virus, to remain in host cells, usually in neurons, for long periods and to retain the ability to replicate.

question

poxviruses

answer

A group of enveloped viruses with linear dsDNA that are the largest and most complex of all viruses. Can infect nearly every animal species. They replicate in parts of the host cell's cytoplasm called viroplasm.

question

Papovaviruses

answer

Small, naked, polyhedral dsDNA viruses that replicate in the nuclei of the host cells. Includes: papilloma, polyoma, vacuolating viruses

question

Hepadnaviruses

answer

Small, enveloped, mostly dsDNA (partially ssDNA) viruses. They cause liver infection.

question

parvoviruses

answer

Small,naked, linear ssDNA viruses. Their genetic information is so limited that they must enlist the aid of an unrelated helper virus or a dividing host cell to replicate. Three genera: dependovirus, parvovirus, erythrovirus.

question

Emerging viruses

answer

Recently discovered and unexpected viruses that were previously endemic but that has expanded its host range to become potential pandemic.

question

Phage therapy

answer

The use of phages aka bacteriophages (viruses that infect bacteria) to treat bacterial disease.

question

Replication cycle

answer

1. Absorption - virus attaches to host cell
2. Penetration - entry of virions or their genome into host cell
3. Synthesis - Use of cell machinery to make new parts
4. Maturation - assembly of viral the synthesized components
5. Release - departure of new virions from host cell.

question

Virulent (lytic) cycle

answer

Phages that lyse its host cell upon release of new viruses.

question

Lytic cycle

answer

The replication process of the type of viruses that end with the lysing of the host cell.

question

Burst time

answer

Time from absorption to release of a virus' lytic cycle.

question

Viral yield aka burst size

answer

The number of new virions released from each bacterial host.

question

Replication curve

answer

Curve that describes and represents viral growth which includes an eclipse period (penetration through biosynthesis) and a latent period (from penetration through phage release).

question

Plaque assay

answer

A way for virologists to estimate phage number using serial dilutions and inoculating them onto a series of plates containing a susceptible bacterial lawn (a layer of bacteria). After incubation the plaques are counted since they represent the areas where viruses have lysed host cells.

question

Plaques

answer

Each plaque represents the progeny from one infectious phage... such counts are reported as plaque-forming units (pfu).

question

Plaque forming units
(PFU)

answer

The estimate count of phages based on the number of plaques seen on a plate

question

Temperate phages

answer

Bacterial attacking viruses that do not necessarily undergo a lytic cycle with its host

question

Lysogeny

answer

A stable, long-term relationship between a phage and its host in which the phage nucleic acid becomes incorporated into the host nucleic acid

question

Prophage

answer

Is the viral DNA within the bacterial chromosome placed there by the phage during its lysogenic state

question

Lysogen

answer

The combination of a bacterium and a temperate phage

question

Lysogenic conversion

answer

When "immunity" is given to a lysogen by its phages that "protects" it from other phages of that same type (same DNA)

question

Lysogenic cycle

answer

The growth of lysogens, meaning, when a bacterial host with phage DNA in its chromosomes undergoes its binary fission the phage DNA gets replicated along with its own and passed down this way. If the phage activates the lytic cycle in any of the daughter cells will by lysed by these phages when they break out.

question

Induction

answer

The term used for when a dormant phage becomes active and initiates the lytic cycle. Reasons: lack of nutrients, presence of chemical toxins, or some other reason for the virus to seek greener pastures elsewhere

question

Uncoating

answer

When the viral genome of an animal virus separates from its protein coat so it can enter the host

question

Monolayers

answer

a layer of cells one cell thick that is spread on a plastic surface. It is used for culturing animal viruses.

question

Subculturing

answer

The process by which cells from an existing culture are transferred to new containers with fresh nutrient media

question

Tissue culture

answer

AKA cell culture: The technique of sub-culturing animal tissue for the study of animal viruses

question

Primary cell cultures

answer

are cultures obtained directly from the animal and are not subcultured

question

Cell strain

answer

What is produced from a primary cell culture when it is repeated and one type becomes dominant

question

diploid fibroblast strains

answer

Immature animal cells that produce collagen and other fibers as well as the substance of connective tissues, such as the dermis of the skin... derived from fetal tissue they retain the ability to divide rapidly

question

continuous cell line

answer

cells that will reproduce for an extended number of generations, i.e. the HeLa cell line which has been maintained and grown in culture since 1951 and has been used in research world wide

question

cytopathic effect (CPE)

answer

The visible effect viruses have on cells

Chapter 10 Viruses – Flashcards

Unlock all answers in this set

Haven't found what you were looking for?

Search for samples, answers to your questions and flashcards