Term
| viruses are _______ outside the cell |
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Definition
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| Viruses are _______ within live cells |
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Definition
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| are viruses composed of cells? |
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Definition
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| are viruses made up of nucleic acid? |
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Definition
| yes, SINGLE nucleic acid (DNA OR RNA) surrounded by protein coat |
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Term
| viruses are what type of parasites? |
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Definition
| viruses are obligate intracellular parasites (as are some bacteria-table 13.1) |
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Definition
| by using cells' synthetic machinery! |
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Term
| what range of diameter do Viruses have? |
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Definition
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Term
| what length do viruses have? |
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Definition
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Term
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Definition
| organisms that viruses infect |
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Term
| what 3 hosts do viruses infect? |
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Definition
| plants, animals, and bacteria |
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Term
| what is an example of a plant virus? |
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Definition
| TMV- Tobacco Mosaic Viruses |
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Term
| what is are four examples of animal viruses? |
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Definition
| Herpes, influenza (flu) virus, poliovirus and rabies virus |
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Definition
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Term
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Definition
| viral protein coat- fig 13.2 |
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Definition
| protein subunits of the capsid |
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Definition
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Term
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Definition
| complete, fully developed, infectious viral particle. |
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Term
| The viral nucleic acid (genome)-can be: |
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Definition
1.DNA or RNA (never both in a VIRION)!
2. Non-segmented or segmented
3. Linear or circular
4. Double or single stranded
5. Single stranded genome:
-Is a sense or (+) strand if it behaves like mRNA
-Is antisense or (-) strand if it can't act like mRNA |
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Term
| when is a single-stranded genome a sense (+) strand? |
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Definition
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Term
| when is a single-stranded genome a antisense (-) strand? |
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Definition
| when it can't behave like mRNA |
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Term
| Viral morphology (shape) is: |
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Definition
| based on capsid architecture |
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Term
| Viral Morphology- Helical viruses: |
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Definition
| -long or curved rods/ threads |
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Term
| What is an example of a Helical virus? |
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Definition
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Term
| Viral Morphology: Polyhedral viruses: |
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Definition
| Icosahedrons structure (many sided) |
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Term
| what is an example of a polyhedral virus? |
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Definition
| Adenoviruses, and picornaviruses |
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Term
| Viral Morphology: Enveloped Viruses: |
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Definition
| Envelope surrounds the capsid, is derived from cellular membranes |
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Term
| what is an example of and enveloped helical virus? |
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Definition
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Term
| what is an example of an enveloped polyhedral virus? |
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Definition
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Term
| Viral Morphology: Complex viruses: |
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Definition
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Term
| what is an example of a complex virus? |
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Definition
| T-even phages (T2 and T4) and poxviruses (smallpox virus and cowpox virus). |
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Definition
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| Viral Taxonomy is based on what 3 things |
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Definition
| nucleic acid type, morphology and replication strategy (retrovirus-HIV example) |
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Term
| Viral Taxonomy-family, genus/species names: |
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Definition
-Family suffix is viridae ex) retrovirade
-Genus suffix is virus ex) lentivirus
-Species: a descriptive name ex) HIV |
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Term
Growing Viruses in the Lab:
1.Bacteriophages |
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Definition
Example-T4 grown in E. coli:
-Lawn of E.coli on AGAR + T4-> areas of clearing on agar, called PLAQUES!
-BROTH culture of E. coli + T4-> CLEARING of broth is an indication of T4 growth! |
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Term
Growing Viruses in the Lab:
2.Animal viruses-where can they be grown in? |
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Definition
1.Lab animals
2.Embryonated eggs
3.Cultured cells (cell lines):
-cells + virus = cytpathic (cell disease) effects (CPE) indicates growth |
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Term
Growth Viruses in the Lab:
3. Cell Line types (2) |
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Definition
1. Primary cell line
2. Continuous cell line (CCL) |
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Term
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Definition
| cells with finite lifespan, cultured directly upon removal from animal. |
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Term
| Continuous cell line (CCL): |
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Definition
| Immortalized cells-growing indefinitely in culture. |
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Term
| Viral Multiplication steps: |
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Definition
1.Attachment
2.Penetration
3.Uncoating
4.Biosynthesis
-includes replication, transcription, and translation
5.Maturation (assembly of body parts)
6.Release |
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Term
| Types of Bacteriophage Multiplication: |
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Definition
| Lytic and Lysogentic cycles |
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Term
| Lytic and Lysogenic cycles are present depending on virus type: |
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Definition
-Both cycles found in lambda phage
-Only lytic cycle in T-even phages. |
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Term
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Definition
| Ends with lysis and death of host cell |
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Term
| what is an example of a type of phage that uses the lytic cycle: |
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Definition
| T-even phages attacking E. coli |
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Term
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Definition
| Phage DNA becomes inserted i host cell genome as PROPHAGE |
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Term
| what is an example of a phage that uses the lysogenic cycle? |
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Definition
| Lambda phage attacking E. coli |
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Term
| how does Lambda phage transfer bacteria DNA to a different bacterium?: |
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Definition
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Term
Animal Virus Multiplication:
Where do DNA VIRUSES multiply: |
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Definition
multiply in the nucleus
-HOST enzymes transcribes viral DNA to give mRNA
-(EXCEPTION: in PROXVIRIDAE, viral enzyme does that!) |
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Term
| Do ALL hosts enzymes of ANIMAL viruses transcribe viral DNA to give mRNA? |
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Definition
| NO!!! PROXVIRADAE- this viruses enzymes transcribes its own DNA to make mRNA. |
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Term
Animal Virus Multiplication:
In Retroviruses: (ex HIV, an RNA Virus) |
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Definition
-Viral RNA is copied to make DNA by RNA-DEPENDENT DNA POLYMERASE, also called REVERSE TRANSCRIPTASE!
-DNA moves from cytoplasm to the nucleus and inserts into the host genome as PROVIRUS |
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Term
Animal Virus Multiplication:
RNA Viruses: |
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Definition
| Multiply in the CYTOPLASM |
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Term
| What are the Enzymes involved in RNA replication? |
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Definition
| RNA-dependent RNA polymerase (RRP) |
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Term
Viruses and Cancer:
Why is viral cause of cancer difficult to establish/diagnose? |
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Definition
Because:
1.Viruses
-are difficult to see
-many infect cells without causing cancer.
2.Cancers:
-are not contagious
-may not develop until long after viral infection is established. |
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Term
Viruses and Cancer:
Viruses that cause cancer are called oncogenic viruses: |
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Definition
-many DNA viruses are oncogenic (ex-Papilloma virus)
-Oncogenic RNA viruses are found only in Retrovirade-and RNA Virus! (HIV) |
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Term
Viruses and Cancer
C. Cancer=uncontrolled cell proliferation cells become transformed and show what? |
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Definition
1. Loss of contact inhibition
2. Chromosome changes
3. Tumor-specific transplantatioleus)n antigens-TSTA-(on cell surface)
4. T antigens (in nucleus) |
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Term
Latent vs. slow viral infections:
-Latent: |
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Definition
-viruses remains for long periods without diseases
-infectious virus appears suddenly
-usually not fatal-does not kill-ex.
-cold sores by latent HSV-1
-Shingles by latent chickenpox virus |
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Term
Latent vs. slow viral infections:
slow/persistent |
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Definition
-a disease process; occurs over long period of time
-infectious virus gradually builds up
-usually fatal-ex-
-AIDS dementia by HIV
-SSPE by measles virus |
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Term
Prions:
Prion disease is caused by what? |
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Definition
| an infectious protein called prions |
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Term
| a Prion disease in sheep, cattle and humans |
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Definition
-sheep: scrapies disease (Sc)
-cattle/cow: mad cow disease (also called bovine spongiform encephalopathy-BSE)
-Humans: Creutzfeld-Kakob disease and Kuru |
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Term
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Definition
-Is a plant disease-cause plant diseases
-caused by naked RNA |
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Term
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Definition
-The RNA is 300-400 nucleotides long
-lik introns, the RNA does not code for a polypeptide |
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Term
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Definition
-coconut cadang cadang viroid (CCCV) disease
-Potato spindle tuber viroid (PSTV) disease |
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