-4- Micro Virology

Front 1

Charles Chamberland

Back 1

Discovered porcelain filters used to filter (remove) bacteria.

Front 2

Dmitri Ivanovsky

Back 2

Discovered that some filtrates remained infectious???

Front 3

Martinus Beijerinck

Back 3

"Contagium vivium fluidium"
(Contagious living fluid)
Later coined the name virus
(meaning poison or venom)

Front 4

isolate
propogate
observe and analyze was not available.

Back 4

The lack of technology needed to: ________,_________, and ________________________ was lacking prior to the 1930s.

Front 5

Wendell stanley

Back 5

Crystallized the first virus (TMV)

Consisted of protein and RNA

Viruses first observed with an electron microscope.

Front 6

Mendel's Particles

Back 6

Gregor mendel

Certain inherited traits seem to be passed from parent to offspring as discrete hereditary "particles".

Front 7

Hershey and Chase

Back 7

Discovered the genetic material of some VIRUSES was DNA

Front 8

1. Contain a single type of nucleic acid, either DNA or RNA.
2. Contain a protein coat (capsid) around the nucleic acid.
3. Some have a envelope (plasma membrane) around the protein coat.
4. Multiply inside living cells (Viruses can't synthsize proteins or generate ATP)
5. take over metabolic activity of host cells.

Back 8

What are the general characteristics and structure of viruses?

Front 9

capsomeres
Immunogenic

Back 9

The general characteristic and structure of a virus consists of protein subunits called _________.

Is Antigenic/___________ (stimulates antibody production)

Front 10

capsid

Back 10

(Characteristic and structure of a virus)

Contain a protein coat (_______) around the nucleic acid.

Front 11

envelope (plasma membrane)

Back 11

Some viruses have an __________ around the protein coat.

Front 12

synthesize

Back 12

(Characteristic and structure of a virus)Multiply inside living cells (viruses can't _________ proteins or generate ATP).

Front 13

host

Back 13

Viruses take over the metabolic activity of _____ cells.

Front 14

clinical
replication

Back 14

Important for _________ control: Difficult to disrupt viral __________ without interfering with host cell function.

Front 15

through an electron microscope.

Back 15

What is the only way you can see a virus?

Front 16

20-14,000 nm

Back 16

What is the size of a virus?

Front 17

Shapes of viruses

Back 17

Helical/Spiral
Icosahedral (20 sided polyhedron)
Enveloped
Complex

Front 18

heat

Back 18

Most viruses are destroyed by >60' C, 140'F

Front 19

Cold

Back 19

This environmental effect has little effect on viruses.

They survive in -76' C for over 1 year.

Front 20

Desiccation

Back 20

This environmental effect tolerate drying on viruses.

Front 21

pH

Back 21

This environmental effect can tolerate from ranges ~5-9.

Front 22

Disinfectants

Back 22

This environmental effect are mostly ineffective on viruses.

Alcohol can destroy lipid enveloped viruses

Front 23

Oxidizing agents

Back 23

What environmental effect is mostly effective, and has to do with Hydrogen Peroxide, chlorine, and iodine.

Front 24

UV light

Back 24

What environment effect damages nucleic acids on viruses?

Front 25

1. Living animals and plants
2. Embryonic eggs
3. Tissue/Cell culture
4. Bacterial culture

Back 25

What is required for cultivation of viruses? (4)

Front 26

Embryonic eggs

Back 26

Virus is injected into embryonic tissues and membranes.

Front 27

Tissue/Cell culture

Back 27

Cells in solution that provides : nutrients, proper osmotic pressure, pH, etc.

include:
primary cell & embryonic cell lines
Continuous/immortal cell lines

Front 28

primary cell & embryonic cell lines

Back 28

Grow for a short time in vitro.

Front 29

Continuous/immortal cell lines

Back 29

Can be maintained in vitro indefinitely.

Front 30

1. Attachment/Adsorption
2. Penetration
3. Biosynthesis
4. Maturation/Assembly
5. Release/Lysis

Back 30

What are the 5 phases of T-even bacteriophage Lytic cycle?

Front 31

Attachment/Adsorption

Back 31

A phase in T-even bacteriophage lytic cycle

Phage tail fibers attach to specific receptors on bacteria.

Front 32

Penetration

Back 32

A phase in T-even bacteriophage lytic cycle

Phage release enzyme -> lysosome dissolves part of the bacteria cell wall. Tail sheath contracts and drives phage core through the cell wall and injects DNA.

Front 33

Biosynthesis

Back 33

A phase in T-even bacteriophage lytic cycle

Viral DNA takes over the machinery of the host cell and begins producing viral DNA and structural components.

Front 34

Maturation/Assembly

Back 34

A phase in T-even bacteriophage lytic cycle

Phage DNA assembles into complete viruses.

Front 35

Release/Lysis

Back 35

A phase in T-even bacteriophage lytic cycle

Phage lysosome breaks down bacterial cell wall and multiplied phages are released.

Front 36

"burst time"

Back 36

The time from adsorption to release.

Front 37

"burst size"

Back 37

The average number of virons released by a cell. (50-200 virons for T-even phage).

Front 38

Lysogeny

Back 38

Viral DNA is incorporated into the host DNA without causing lysis of the host cell.

Front 39

Lysogenic cell

repressor protein.

Back 39

A cell containing a prophage (provirus). Prophage genes are repressed by a _________ _______.

Front 40

Latency

Back 40

Ability to remain in host cells for long periods.

Front 41

Induction/Excision
Specialized Transduction

Back 41

What are the 2 phage conversions?

Front 42

Induction/Excision

Back 42

Certain environmental factors may cause a prophage to revert to the lytic cycle.

e.g. UV light or certain chemicals.

Front 43

Specialized Transduction

Back 43

When a prophage is excised from the host chromosome it can take with it adjacent DNA from the bacterial chromosome.

Front 44

Animal viruses

Back 44

Attachment
Penetration occurs by endocytosis
Uncoating by viral or host cell enzymes.
Biosynthesis
Maturation and Release (budding)

Front 45

Latent viral infections

Back 45

Virus remains in asymptomatic host cell for long periods. Reactivated by: fever, UV light, stress, trama, hormonal changes, and repair mechanisms in the cell.

eg. cold sores and shingles

Front 46

Wilhelm Ellerman & Olaf Bang
F. Peyton Rous
Michael Bishop and Harold Varmus

Back 46

Who worked on viruses and cancer?

Front 47

Wilhelm Ellerman & Olaf Bang

Back 47

Found that leukemia could be transferred to healthy chickens by cell-free filtrates containing viruses.

Front 48

F. Peyton Rous

Back 48

Found that chicken sarcoma (cancer of conn. tissue) similarly transmitted.

Oncogenes (cancergenes)

Front 49

Oncogenes (cancergenes)

Back 49

Genes that can cause a normal cell to be transformed into a malignant cell.

Front 50

Michael Bishop and Harold Varmus

Back 50

Won noble prize

Cancer-producing genes carried by viruses are derived from the animal cells genome.

Front 51

Proto-oncogenes

Back 51

Normally direct synthesis of products for cell growth and development. When a virus containing an oncogene is introduced into a cell, the cell may be unable to regulate synthesis of the virus's oncogene. The excess product may result in uncontrolled cell division.