Premed - Lecture 4. Introduction To Virology

Front 1

Meaning of Virus:

Back 1

Poison, Latin.

Front 2

Virus first identified as:

Back 2

Filterable infectious agents (passed though filters that remove bacteria).

Front 3

First virus discovered:

Back 3

Yellow Fever Virus

Front 4

Define: Acellular (what viruses are).

Back 4

inert, not considered living.

Front 5

True / False? Viruses are Obligate intracellualr parasites?

Back 5

True.

Front 6

How do viruses replicate?

Back 6

Self assembly of individual components within the host cell.

Front 7

What does a viral infection slow down?

Back 7

Slows down RNA (in host cell synthesis).

Front 8

What is a 'VIRION'

Back 8

A complete virus.

Front 9

What is 'Genome' mean?

Back 9

Nucleic Acid (either in DNA or in RNA)

Front 10

Properties of a Genome:
sided, shape, hapolid vs. diploid.

Back 10

1. Single or Double sided.
2. Linar, circular, RNA is segmented
3. Usually haploid, some diploid.

Front 11

What is a "capsid"

Back 11

Proteins shell covering the nucleic acid

Front 12

Shape of capsid?

Back 12

helical or icosahedral.

Front 13

What are capsids made up of?

Back 13

repeated subunits known as capsomeres.

Front 14

Genome + capsid =

Back 14

Nucleocapsid = a virion.

Front 15

2 Functions of the capsid:

Back 15

1. protect the nucleic acid from environmental damage
2. mediates attachment of the virus to the host cell.

Front 16

Naked viruses are:

Back 16

Viruses that lack an envelope.

Front 17

Are all the helical viruses of animals are enveloped?

Back 17

Yes. All Helical viruses of animals are enveloped.

Front 18

Where is the helix coiled?

Back 18

Within the envelope.

Front 19

What shape does helix have?

Back 19

Rough Sphere shape.

Front 20

Are enveloped viruses flexible?

Back 20

Yes, enveloped viruses are flexible.

Front 21

What derives the envelope?

Back 21

Host cell membranes.

Front 22

Where are virus specific proteins inserted?

Back 22

Inserted into the membrane.

Front 23

Structural proteins are found in...

Back 23

mature virus (all proteins ).

Front 24

Define: Non-structural proteins:

Back 24

Those viral proteins found in the cell but not packaged in the virion.

Front 25

How many proteins does an icosahedral have?

Back 25

20 proteins all around.

Front 26

* *
Structure in virus:
Envelope (define)

Back 26

A lipid bilayer from host cell and viral glycoproteins.

Front 27

* *
Structure in virus:
Peplomers

Back 27

Viral gylcoprotein spikes, binding to host cell

Front 28

* *
Structure in virus:
Matrix protein

Back 28

Mediate attachment of capsid with the envelope.

Front 29

* *
Structure in virus:
Packaged enzymes

Back 29

Facilitate initial viral replication (polymerases, proteases).
Located inside the nucleocapsid or in teh space between the capsid and envelope.

Front 30

Viral sizes (approx. between)

Back 30

18 nm to 300nm

Front 31

List some Human DNA Viruses:

Back 31

Parvovirus
Papoavirus
Adenovirus
Herpesvirus
Poxvirus

Front 32

List some Human RNA Viruses:

Back 32

Picomavirus
Reovirus
Togavirus
coronavirus
Orthomyxovirus
Rhabdovirum

Front 33

What does nucleocapsid structure depend on?

Back 33

The arrangement of the subunits of capsid (capsomeres)

Front 34

Define Viron Morphology Icosahedral means:

Back 34

Are capsomeres arranged in 20 traingles that form a sysmmetric figure (polyhedral).

Front 35

Helical means:

Back 35

Capsomeres arranged in a hollow coil that appear like a rod.

Front 36

Complex means:

Back 36

Nonsymmetrical

Front 37

Spikes and peplomers are used for:

Back 37

adhesion, viral attachment proteins

Front 38

Viruses with envelopes are ____ proteins:

Back 38

...are MATRIX proteins.

Front 39

Proteins on the envelope are, ____ proteins:

Back 39

.... are VIRAL proteins.

Front 40

Pleomorphic / round are found:

Back 40

in enveloped viruses.

Front 41

Which viruses are exempt from the pleomorphic type"

Back 41

pox virus and rabies virus.

Front 42

DNA Viruses (List a few)

Back 42

Poxvirus
Herpes Virus
Adenovirus
Papulloma virus
Parvovirus

Front 43

RNA Viruses (List a few)

Back 43

Influenza virus
Rotavirus
mumps virus
eastren equine
Rabies Virus
HIV / AIDS
Corona virus (common cold)
Poliovirus
LCM virus

Front 44

How many proteins are around a virus?

Back 44

Very few.

Front 45

What is a naked icosahedral also called?

Back 45

Adenovirus

Front 46

How many sides does an icosahedral have?

Back 46

12 vertices and 20 triangular sides

Front 47

Capsides with icosahedral symmertry are more complex because:

Back 47

have several different polypeptides grouped into structural subassemblies --> CAPSOMERS

Front 48

What is the bond of capsomers?

Back 48

Hydrogen bonded to each other

Front 49

Where is the nucleic acid genome located?

Back 49

within the empty space, rigid.

Front 50

Basic Shape of Rabies Virus is:

Back 50

Bullet shape.

Front 51

T or FL
Rabies virus is Helical Enveloped Virus.

Back 51

True.

Front 52

Example of Enveloped virus?

Back 52

HIV

Front 53

Basics of what happens with the HIV virus:

Back 53

RNA taken through enzyme
Makes DNA copies of RNA
Lose T cells, lose immunity,
Gets into cell by Glycoprotein 120
Nucleic Acid is wedge shaped cell
Retrovirus (have unique shape inside the cell).

Front 54

List 2 complex viruses:

Back 54

Bacteriophage
Smallpox virus

Front 55

Define: Syncytua

Back 55

Melting many cells together to form a multi-nucleic cell together (not one single cell but a single structure in cytoplasm)

Front 56

COMPARE between the 2
Enveloped Virus vs. Naked Virus:
Environment

Back 56

Enveloped: Liable
Naked: Stable

Front 57

COMPARE between the 2
Enveloped Virus vs. Naked Virus:
Spread

Back 57

Enveloped: must stay wet, large droplets/ secretions
Naked: easily spread by water, dust, food, hands, etc.

Front 58

COMPARE between the 2
Enveloped Virus vs. Naked Virus:
Enters cells...

Back 58

Enveloped: by fusion with cytoplasmic membrane lipids
Naked: through receptor mediated aveneue

Front 59

COMPARE between the 2
Enveloped Virus vs. Naked Virus:
Released:

Back 59

Enveloped: budding through cell membrane with no cell death
Naked: exist host cell by lysis and death

Front 60

Naming Common Viruses can be related to:

Back 60

- Target tissue
- geogrpahy/ location
- shape
- transmission

Front 61

Naming formal viruses can be through:

Back 61

end in viridae
genera name

Front 62

RNA Viruses are mostly:
naked or enveloped?

Back 62

enveloped

Front 63

Viruses are classified on the basis of their (3 tings):

Back 63

1. genome
2. structure
3. enveloped or not

Front 64

Why do DNA have neoplastic potential (2 things)

Back 64

1. have intranuclear residence
2. might damage host DNA

Front 65

Except for influenze, where does RNA replicate?

Back 65

In the host cell cytoplasm.

Front 66

Except for the pox virus where does DNA replicate?

Back 66

In the nucleus.

Front 67

3 steps of entry in viral replication:

Back 67

1. attachment
2. penetration
3. uncoating

Front 68

6 steps to Viral replication:

Back 68

1. Attach
2. Penetrate
3. uncoat
4. macromolecular synthesis & replication
5. assembley and release
6. progenyvirus - exit from host cell

Front 69

Lysis means:

Back 69

Immediate death / termination.

Front 70

Define: Persistent Infection:

Back 70

Viral genome integrate with host cell genome.
Remain dormant
Reactivate can cause disease

Front 71

Define: Cytopathic Effect

Back 71

Change in shape of infected cell due to viral infections

Front 72

What are Prions?

Back 72

Subcellular infectious agents. Not viruses.

Front 73

Prion composition:

Back 73

Only protein
No DNA, No RNA

Front 74

Example of prion:

Back 74

Mad cow disease.