Ch.13 Viruses, Viroids, & Prions Flashcards
Characteristics of Viruses:
~ ———: require living host cells to multiply
~ Contain — or —
~ Contain a ——
~ No —
~ No —— mechanisms
- Obligatory Intracellular Parasites
- DNA or RNA
- Protein Coat
- Ribosomes
- ATP-generating
Host Range:
~ The — of —— a virus can infect
~ Most viruses infect only — types of cells in one host
* Determined by specific host —— and ——
~ Bacteriophage, — that ——
~ Range from —nm to —nm in length
- Spectrum of host cells
- Specific
- Attachment sites, Cellular Factors
- Viruses that infect bacteria
- 20nm to 1000nm
Viral Structure:
~ Virion: —, —— viral particle
* Nucleic acid, DNA or RNA can be — or — —; — or —
- Complete, fully developed
- Single or Double Stranded; Linear or Circular
Viral Structure:
~ Capsid: —— made of —
Protein coat made of capsomeres (subunits)
Viral Structure:
~ Envelope: —,—, and — coating on some viruses
Lipid, protein, and carbohydrate
Viral Structure:
~ Spike: — from ——
Projections from outer surface
General Morphology:
~ Helical Viruses:—, ——
Hollow, cylindrical capsid
General Morphology:
~ Polyhedral Viruses: ——
Many-sided
General Morphology:
~ Complex Viruses: ——
Complicated structures
Taxonomy of Viruses:
~ Genus named end in —
~ Family names end in —
~ Order names end in —
- -virus
- -viridae
- -ales
Taxonomy of Viruses:
~ Viral Species: a group of viruses sharing the same —— and ——
* Descriptive common names are used for —
* Subspecies are designated by a —
- Genetic Information & Ecological niche (host)
- Species
- Number
Growing Bacteriophages in the Lab:
~ Viruses must be grown in — cells
~ Bacteriophages are grown in —
* Bacteriophages form —, which are clearings on a lawn of — on the surface of agar
- Each plaque corresponds to a single virus; can be expressed as ———
- Living
- Bacteria
- Plaques, Bacteria
- Plaque Forming Units (PFU)
Growing Animal Viruses in the Lab:
~ In — animals
~ In embryonated eggs:
* Virus — into the egg
* Viral growth is signaled by — or — of the embryo
- Living
- Injected
- Changes or Death
Viral Multiplication:
~ For a virus to multiply:
* It must invade a ——
* It must take over the ———
- Host Cell
- Host’s Metabolic Machinery
Multiplication of Bacteriophages:
~ Lytic Cycle: phage cause — and — of the ——
- Lysis
- Death
- Host Cell
Multiplication of Bacteriophages:
~ Lysogenic Cycle:
*— DNA is incorporated in the — DNA
* — conversion
* Specialized —
- Phage, Host
- Phage
- Transduction
T-Even Bacteriophages: The Lytic Cycle
~ Attachment: phage attaches by the —— to the ——
- Tail Fibers
- Host Cell
T-Even Bacteriophages: The Lytic Cycle
~ Penetration: phage — opens the ——; tail sheath contacts to force the —— and — into the cell
- Lysozyme
- Cell Wall
- Tail Core
- DNA
T-Even Bacteriophage: The Lytic Cycle
~ Biosynthesis: production of —— and —
- Phage DNA
- Proteins
T-Even Bacteriophages: The Lytic Cycle
~ Maturation: assembly of ——
Phage Particles
T-Even Bacteriophages: The Lytic Cycle
~ Release: Phage — breaks the ——
- Lysozyme
- Cell Wall
Bacteriophage Lambda: The Lysogenic Cycle
~ Lysogenic: ———
Phage remains latent
Bacteriophage Lambda: Lysogenic Cycle
~ Phage DNA incorporates into —— DNA
* Inserted phage DNA is known as a —
* When the host cell replicated its chromosome, it also replicates ——
* Results in ——, the host cell exhibits new properties
- Host Cell
- Prophage
- Prophage DNA
- Phage Conversion
Bacteriophage Lambda: Lysogenic Cycle
~ Specialized Transduction
* Specific bacterial genes transferred to another bacterium via a —
* Changes —— of the —
- Phage
- Genetic Properties, Bacteria
Multiplication of Animal Viruses:
~ Attachment: viruses attach to the ——
Cell membrane
Multiplication of Animal Viruses:
~ Entry by ——— or —
Receptor-mediated endocytosis or fusion
Multiplication of Animal Viruses:
~ — by viral or host —
- Uncoating
- Enzymes
Multiplication Animal Viruses:
~ Biosynthesis: production of —— and —
Nucleic acid and proteins
MUltiplication of Animal Viruses:
~ Maturation: —— and —— assemble
Nucleic acid and capsid proteins
Multiplication of Animal Viruses:
~ Release by — or —
Budding (enveloped viruses) or rupture
The Biosynthesis of DNA Viruses:
~ DNA viruses replicate their DNA in the — of the host using ——
~ Synthesize — in the cytoplasm using host cell —
- Nucleus, Viral Enzymes
- Capsid, Enzymes
The Biosynthesis of DNA Viruses:
~ Adenoviridae
* —— DNA, —
* —— in humans
* — in animals
- Double-Stranded, Enveloped
- Respiratory Infections
- Tumors
The Biosynthesis of DNA Viruses:
~ Poxviridae
* —— DNA, —
* Cause ——: — and — virus
- Double Stranded, Enveloped
- Skin Lesions, Vaccinia & Smallpox (Orthopoxvirus)
The Biosynthesis of DNA Viruses:
~ Herpesviridae: —— DNA, —
* HHV & HHV2, ——; causes ——
- Double stranded, Enveloped
- Simplexvirus, Cold Sores
The Biosynthesis of DNA Virus:
~ Herpesviridae
* HHV 3, —; causes —
- Varicellovirus
- Chickenpox
The Biosynthesis of DNA Virus:
~ Herpesviridae
* HHV4, —; causes —
- Lymphocryptovirus
- Mononucleosis
The Biosynthesis of DNA Viruses:
~Herpesviridae
*HHV 5, —
Cytomegalovirus
The Biosynthesis of DNA Virus:
~ Herpesviridae
* HHV 6 & HHV 7, —
Roseolovirus
The Biosynthesis of DNA Virus:
~ Herpesviridae
* HHV 8 —, causes ——
- Rhadinovirus
- Kaposi’s Sarcoma
The Biosynthesis of DNA Virus:
~ Papovaviridae: —— DNA, —
* Papillomavirus: causes —, can transform — and cause —
- Double Stranded, Noneveloped
- Warts, Cells, Cancer
The Biosynthesis of DNA Virus:
~ Hepadnaviridae: —— DNA, —
* —— Virus
* Use ——- to make DNA from RNA
- Double Stranded, Enveloped
- Hepatitis B
- Reverse Transcriptase
The Biosynthesis of RNA Viruses:
~ Virus multiplies in the host cell’s — using ————
- Cytoplasm
- RNA-dependent RNA Polymerase
The Biosynthesis of RNA Virus:
~ ssRNA; +(sense) Strand
* Viral RNA serves as — for ——
- mRNA
- Protein Synthesis
The Biosynthesis of RNA Viruses:
~ ssRNA; - (antisense) strand
* Viral RNA is transcribed to a — strand to serve as — for ——
~ dsRNA; ———
- +
- mRNA
- Protein Synthesis
- Double Stranded RNA
The Biosynthesis of RNA Viruses:
~ Picornaviridae: —— RNA, — strand, —
* —: poliovirus and coxsackievirus
* —: common cold
* —— virus
- Single Stranded, +, Noneveloped
- Enterovirus
- Rhinovirus
- Hepatitis A
The Biosynthesis of RNA Virus:
~ Togaviridae: —— RNA, — strand, —
* —: transmitted by arthropods; includes chikugunya
* —: rubella
- Single Stranded, +, enveloped
- Alpha virus
- Rubivirus
The Biosynthesis of RNA Viruses:
~ Rhabdoviridae: —— RNA, — strand, — RNA strand
* —: rabies
* Numerous — diseases
- Single Stranded, -, One
- Lyssavirus
- Animal
The Biosynthesis of RNA Virus:
~ Reoviridae: —— RNA, —
* —
* —
- Double-Stranded, Noneveloped
- Reovirus (respiratory enteric orphan)
- Rotavirus (mild respiratory infections and gastroenteritis)
Biosynthesis of RNA Viruses That Use DNA:
~ —— RNA, produce —
* Use —— to produce DNA from the viral genome
- Viral DNA integration into the host chromosome as a —
- Single Stranded, DNA
- Reverse Transcriptase
- Provirus
Biosynthesis of RNA Viruses That Use DNA:
~ —— RNA, produce —
* —: —(HIV), oncovirus
- Single Stranded, DNA
- Retroviridae, Lentivirus
Viruses and Cancer:
~ Severall types of cancer are caused by viruses
* May develop long after a ——
* Cancers caused by viruses are not —
- Viral Infection
- Contagious
Sarcoma: cancer of ——
Connective Tissue
Adenocarcinomas: cancers of ———
Glandular Epithelial Tissue
Oncogenes transform — cells into — cells
- Normal
- Cancerous
Oncogenic viruses become — into the host cells — and induce —
- Integrated
- DNA
- Tumors
A transformed cell harbors a ———— on the surface and a —— in the nucleus
- Tumor Specific Antigen (TSTA)
- T antigen
DNA Oncogenic Viruses:
~ —-
~ —: Epstein-Barr Virus
~ —
~ —: human papillomavirus
~ —: Hepatitis B virus
- Adenoviridae
- Herpesviridae
- Poxviridae
- Papoviridae
- Hepadnaviridae
RNA Oncogenic Virus:
~ Retroviridae: viral RNA is transcribed to —, which can integrate into — DNA
* HTLV-1 and HTLV-2 cause adult ——— and —
- DNA, Host
- T-cell Leukemia and Lymphoma
Latent virus remain in — host cell for — periods
* May reactivate due to changes in —
~ ——, —
- Asymptomatic, Long
- Immunity
- Cold sores, shingles
A ——— occurs gradually over a long period; is generally fatal
* ——— (measles virus)
- Persistent Viral Infection
- Subacute Sclerosing Panecephalitis
Prions:
~ P— I— P—
~ Inherited and transmissible by —,—, and ——
~ Spongiform Encephalopathies
* “———“, ———, ————, ———, ——
- Proteinaceous Infectious Particles
- Ingestion, Transplant, and Surgical Instruments
- Mad Cow Disease, Creutzfeldt-Jakob Diseases (CJD), Gerstmann-Straussler-Scheinker Syndrome, Fatal Familial Insomnia, Sheep Scrapie
Prions:
~ PrP^c: normal cellular ——, on the ——
- Prion Protein
- Cell Surface
Prions:
~ PrP^Sc: ——; accumulates in ——, forming —
- Scrapie Protein
- Brain Cells
- Plaques
Plant Viruses: enter through — or via —
* Plant cells are generally protected from disease by an ———
- Wounds, Insects
- Impermeable Cell Wall
Viroids: — pieces of ——
* Cause ——— disease
- Short, Naked RNA
- Potato Spindle Tuber Disease