Bsc 380 - Chapter 13

Front 1

Adolf Mayer, in 1886, discovered that the tobacco mosaic disease was transmissible.

Dimitri Iwanowski, in 1892, found that filtered sap still caused tobacco mosaic disease. He called the filtered sap a contagious fluid or filterable agent.

Wendell Standley, in 1935, isolated the tobacco mosaic virus.

Back 1

____, in ____, discovered that the tobacco mosaic disease was ____.

____, in ____, found that ____ still caused tobacco mosaic disease. He called the filtered sap a ____ or ____.

____, in ____, isolated the tobacco mosaic virus.

Front 2

Walter Reed, in 1901, discovered Yellow Fever.

Felix d'Herelle, in 1917, discovered bacteriophages and suggested phage therapy.

In the 1930s, the the term virus was introduced and electron microscopy was invent.

Back 2

____, in ____, discovered Yellow Fever.

____, in ____, discovered bacteriophages and suggested phage ____.

In the ____, the the term virus was introduced and ____ was invent.

Front 3

Viruses are obligate intracellular pathogens.

Viruses host range can be either highly specific or general.

Viruses have either DNA or RNA but never both.

Viruses are protected by a protein coat (capsid).

The surface proteins on a virus are highly susceptible to mutations.

Viruses cause synthesis of specialized structures to transfer viral particles to other cells.

Outside of a host, the virus is called a virion which is a complete, fully developed, infectious viral particle.

Back 3

Viruses are ____ pathogens.

Viruses host range can be either ____ or ____.

Viruses have either ____ or ____ but never both.

Viruses are protected by a ____ (____).

The surface proteins on a virus are highly ____ to ____.

Viruses cause synthesis of ____ to transfer viral particles to other ____.

Outside of a host, the virus is called a ____ which is a complete, fully ____, infectious viral ____.

Front 4

The oldest system of viral classification was based on symptomolgy.

The International Committee on Taxonomy of Viruses, in 1966, described viruses as elementary bio-systems. They classified viruses into orders, families, genera, and species.

There are over 1,500 officially recognized virus species.

Back 4

The oldest system of viral classification was based on ____.

The ____, in 1966, described viruses as ____ bio-systems. They classified viruses into ____, families, ____, and species.

There are over ____ officially recognized virus ____.

Front 5

Primary means of viral classification:
Nucleic acid
Replication strategy
Morphology of protein coat (capsid)

Back 5

Primary means of viral ____:
____
____
____

Front 6

Capsid Morphology:
Helical
Polyhedral

Back 6

Capsid Morphology:
____
____

Front 7

Viral envelopes are acquired from the host cell when budding. It is composed of phospholipids and proteins.

The envelope contains glycoproteins that are virally coded spikes and plays a role in host recognition and attachment.

Spikes on the viral envelope are likely to mutate resulting in different viral strains.

Viruses containing nontypical structures (accessories) are considered complex viruses.

Back 7

Viral ____ are acquired from the host cell when budding. It is composed of ____ and ____.

The ____ contains glycoproteins that are ____ spike and plays a role in host ____ and ____.

Spikes on the viral ____ are likely to mutate resulting in different ____.

Viruses containing ____ (accessories) are considered ____ viruses.

Front 8

Complex virus structures:
Sheath
Tail fiber
Pin
Baseplate

Back 8

Complex virus structures:
____
____
____
____

Front 9

Viral Taxonomy:
Order - virales
Family - viridae
Genus - virus
Species - common name / number designation

Back 9

Viral Taxonomy:
Order - ____
Family - ____
Genus - ____
Species - ____

Front 10

In order to isolate and cultivate viruses, they must be grown in living cells.

Cytopathic effects are visible or observable effects a virus has on a cell.

Back 10

In order to ____ and ____ viruses, they must be grown in living cells.

____ are visible or observable effects a virus has on a cell.

Front 11

Animal viruses may be grown in living animals, embryonated eggs, or cell cultures.

Back 11

Animal viruses may be grown in ____, ____, or ____.

Front 12

Primary cell lines die after a certain number of divisions where as continuous cell lines (transformed cells) are cancer cells with no cell division control mechanisms and can continue to grow indefinitely.

Back 12

____ die after a certain number of divisions where as ____ (transformed cells) are ____ with no cell division control mechanisms and can ____ to grow ____.

Front 13

Virus identification:
Serological tests detect antibodies against viruses in a patient.
Nucleic acids used in virus identification are RFLPs and PCR.

Back 13

Virus identification:
____ detect antibodies against viruses in a patient.
Nucleic acids used in virus ____ are ____ and ____.

Front 14

Bacteriophages multiply by either the lytic cycle or the lysogenic cycle.

In the lytic cycle, phages cause lysis and death of the host cell.

In the lysogenic (temperate) cycle, temperate phages incorporate DNA into the host DNA.

Back 14

Bacteriophages multiply by either the lytic cycle or the lysogenic cycle.

In the ____ cycle, phages cause lysis and ____ of the host cell.

In the ____ (____) cycle, ____ phages incorporate DNA into the host DNA.

Front 15

A virus within a host is called a prophage.

Back 15

A virus within a host is called a ____.

Front 16

Lytic Cycle (Phage):
Attachment - tail fibers attach to host cell.
Penetration - lysozyme opens the cell wall, tail sheath contracts to force the tail core and DNA into cell.
Biosynthesis - production of DNA and proteins.
Maturation - assembly of newly synthesized phage particles.
Release - lysozymes break open the cell wall releasing the new viruses.

Back 16

____ Cycle (Phage):
Attachment - ____ attach to host cell.
____ - lysozyme opens the cell wall, ____ contracts to force the ____ and DNA into cell.
Biosynthesis - production of ____ and ____.
____ - assembly of newly synthesized ____.
Release - ____ break open the cell wall ____ the new viruses.

Front 17

How many new phage particles are released by lysis is called burst size.

The burst time is how long it takes for the cell to burst during the lytic cycle.

The eclipse period is when there are no viruses detectable because they are all within hosts.

Back 17

How many new phage ____ are released by lysis is called ____.

The ____ is how long it takes for the cell to burst during the ____.

The ____ is when there are no viruses ____ because they are all within ____.

Front 18

During the lysogenic cycle, the prophage may excise from the bacterial chromosome by another recombination event, initiating a lytic cycle.

Back 18

During the ____ cycle, the prophage may ____ from the bacterial chromosome by another____ , initiating a lytic cycle.

Front 19

Important results of lysogeny:
Immunity to re-infection from the same type of prophage
Phage conversion due to viral DNA (viral factors, etc.)
Specialized transduction

Back 19

Important results of ____ :
____ to re-infection from the same type of ____
Phage ____ due to viral DNA (____ , etc.)
Specialized ____

Front 20

Specialized transduction occurs when a phage genome excises an adjacent gene from the host. The phage then infects another cell adding the new gene to the new host giving the host new abilities.

Back 20

____ occurs when a phage genome ____ an ____ gene from the host. The phage then ____ another cell adding the ____ gene to the new host giving the host new ____ .

Front 21

Multiplication of Animal viruses:
Attachment - viruses attaches to cell membrane
Penetration - by endocytosis or fusion
Uncoating - by viral or host enzymes
Biosynthesis - production of nucleic acid and proteins
Maturation - nucleic acid and capsid proteins assemble
Release - by budding (enveloped viruses) or rupture

Back 21

____ of Animal viruses:
Attachment - viruses attaches to ____
____ - by endocytosis or ____
Uncoating - by ____ or ____ enzymes
____ - production of nucleic acid and ____
Maturation - ____ and ____ assemble
____ - by budding (____ viruses) or ____

Front 22

Attachment of animal viruses:
chemical attraction
no tails or tail fibers
glycoprotein spikes or other attachment molecules

Back 22

____ of animal viruses:
chemical ____
no ____ or ____
____ spikes or other attachment ____

Front 23

Only animal viruses with envelopes undergo uncoating, naked viruses do not.

Animal DNA viruses often enter the nucleus to replicate.

Animal RNA viruses often replicate in the cytoplasm.

Back 23

Only animal viruses with ____ undergo uncoating, ____ viruses do not.

Animal ____ viruses often enter the nucleus to replicate.

Animal ____ viruses often replicate in the cytoplasm.

Front 24

Viral proteins are produced from positive sense RNA.

Retroviruses use reverse transcriptase to produce DNA from the viral RNA.

Back 24

Viral proteins are produced from ____ RNA.

Retroviruses use ____ to produce DNA from the viral ____.

Front 25

Once a virus has inserted its DNA into a host's DNA it is known as a provirus and is never removed or excised.

Back 25

Once a ____ has inserted its DNA into a host's DNA it is known as a provirus and is never removed or ____.

Front 26

Viral DNA is transported into the host cell's nucleus and integrated as a provirus where it may divide indefinitely with the host's DNA.

Back 26

____ is transported into the host cell's nucleus and integrated as a ____ where it may divide ____ with the host's DNA.

Front 27

Transcription of the provirus may occur, producing RNA for new retrovirus genomes and RNA that codes for that retrovirus capsid and envelope proteins.

Back 27

____ of the provirus may occur, producing RNA for new ____ genomes and RNA that codes for that retrovirus capsid and ____.

Front 28

In RNA positive-sense strand viruses, viral RNA functions as a template for synthesis of RNA polymerase which copies negative-sense strand RNA to make mRNA in cytoplasm.

In RNA negative-sense strand viruses, viral enzymes copy viral RNA to make mRNA in cytoplasm.

In RNA double stranded viruses, viral enzymes copy negative-sense strand RNA to make mRNA in cytoplasm.

Back 28

In RNA ____ strand viruses, viral RNA functions as a template for synthesis of ____ which copies ____ strand RNA to make mRNA in cytoplasm.

In RNA ____ strand viruses, viral enzymes copy viral ____ to make mRNA in ____.

In RNA ____ stranded viruses, viral enzymes copy negative-sense strand RNA to make ____ in cytoplasm.

Front 29

Most DNA viruses assemble in and are released from nucleus into cytosol.

Most RNA viruses develop solely in the cytoplasm.

Back 29

Most DNA viruses ____ in and are released from nucleus into ____.

Most ____ viruses develop solely in the ____.

Front 30

Enveloped viruses cause persistent infections.

Viruses that release through budding have a slow release time.

Naked viruses are released by exocytosis or may cause lysis and death of host cell.

Back 30

Enveloped viruses cause ____ infections.

Viruses that release through ____ have a slow release time.

____ viruses are released by exocytosis or may cause ____ and ____ of host cell.

Front 31

Bacteriophages attach using tail fibers to cell wall proteins while animal viruses attachment sites are plasma membrane proteins and glycoproteins.

Bacteriophages inject their DNA into the host cell while animal viruses capsid enter by endocytosis or fusion.

Bacteriophages do not undergo uncoating but animal viruses uncoating is done by enzymatic removal of capsid proteins.

Bacteriophages biosynthesis is done in the cytoplasm while animal viruses in undergo biosynthesis in the nucleus for DNA viruses and cytoplasm for RNA viruses.

Bacteriophages cause chronic infection by lysogeny while animal viruses cause chronic infection by latency, slow viral infections, and cancer.

Bacteriophages are released by host cell lysis while animal viruses are released by budding if they have an envelope and non-enveloped viruses rupture the plasma membrane.

Back 31

Bacteriophages attach using ____ to cell wall proteins while ____ attachment sites are ____ and ____.

Bacteriophages ____ their DNA into the host cell while animal viruses capsid enter by ____ or ____.

Bacteriophages do not undergo ____ but animal viruses ____ is done by enzymatic removal of ____.

Bacteriophages biosynthesis is done in the ____ while animal viruses in undergo biosynthesis in the ____ for DNA viruses and ____ for RNA viruses.

Bacteriophages cause chronic infection by ____ while animal viruses cause chronic infection by ____, slow ____, and ____ .

Bacteriophages are released by ____ while animal viruses are released by ____ if they have an envelope and non-enveloped viruses rupture the ____.

Front 32

Oncogenes transform or mutate normal cells into tumor cells.

Oncogenes cause increased growth and loss of contact inhibition.

Oncogenes tend to be misshaped and exhibit chromosomal abnormalities.

Oncogenes are activated by:
mutagenic chemicals
radiation
viruses

Some viruses can bring their own oncogenes to a cell.

Back 32

____ transform or mutate normal cells into ____ cells.

____ cause increased ____ and loss of contact ____.

____ tend to be misshaped and exhibit ____.

____ are activated by:
____
____
____

Some viruses can bring their own ____ to a cell.

Front 33

Protooncogenes are cells that force cellular division while tumor suppressor genes stop cellular division.

Back 33

____ are cells that force cellular division while ____ stop cellular division.

Front 34

Oncoviruses are viral DNA integrated into the hosts DNA and induce tumors.

RNA viruses cannot be oncoviruses unless it is a retrovirus.

Back 34

____ are viral DNA integrated into the hosts ____ and induce ____.

____ viruses cannot be ____ unless it is a retrovirus.

Front 35

Latent viral infections can remain dormant in asymptomatic host cells for long periods. Examples are cold sores and shingles.

Persistent viral infections cause diseases that progress slowly over a long period of time and are generally fatal. An example is the measles virus.

Back 35

____ infections can remain dormant in ____ host cells for long periods. Examples are ____ and ____.

____ infections cause diseases that progress ____ over a long period of time and are generally ____. An example is the ____.

Front 36

Plant viruses can only enter through wounds or via insect bites.

Once infected a plant virus may be transmitted in pollen.

Back 36

____ can only enter through wounds or via ____.

Once infected a ____ may be transmitted in ____.

Front 37

Viroids, which can cause infectious disease in plants and animals, are naked RNA.

Back 37

____, which can cause infectious disease in ____ and animals, are ____ RNA.

Front 38

Spongiform encephalopathies, an inflammation of neurons, is caused by prions.

Sheep scrapie
Creutzfeldt-Jakob disease
Gerstmann-Straussler-Scheinker disease
fatal familial insomia
mad cow disease

Back 38

____ , an inflammation of neurons, is caused by prions.

____
____ disease
____ disease
____ insomia
____ disease

Front 39

Prions are proteinaceous infectious particle and cause inherited and transmissible diseases.

Prions are incorrectly folded proteins.

Inherited prions are proteins that have beta pleated sheets instead of alpha helixes.

Infectious prions force proteins to refold incorrectly.

Back 39

Prions are ____ infectious particle and cause ____ and ____ diseases.

Prions are incorrectly ____ proteins.

Inherited prions are proteins that have ____ instead of ____.

____ prions force proteins to refold ____.

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