Final Exam: Virus Flashcards
______ distinct biological entities belonging to the infectious agents group of microbial world
Viruses
____ Best described as obligate intracellular parasites
- provide example of “cellular hijackers”
Viruses
______ invade/enter host cells and use the metabolic machine and resources of the host cells to make more copies of themselves.
- host all as hostage
- uses and abuse host cellulor resources
Viruses
______ has 2 common features, 1. all enter + replicate inside to make more copies of themselves
Viruses
______ has 2 common features, 2. all exit and are shedded to betransmitted into new host
Viruses
______ particles with a protein coat and genetic material; protein coat call capsids that protects genetic material
viruses
______ genetic material (aka genome) is ether DNA or RNA (never both) packaged inside with limited codin. Is the reasons why its so dependent on host cells for replication.
Viruses
Viruses _____ is made of subunit capsomers/capsomeres
capsids
Virus have _______ viral proteins which includes structral proteins and non structural proteins which includes enzymes unique to virus and regulator protein.
Genome encodes
influenza virus, common cold virus and zikka virus which is transmitted by mosquitos are _______.
RNA genome
______ human Papillone virus (HPV) are herpes family
DNA Virus
DNA virus of ______ are cold sores above the waist.
herpes simplex I (HSV-I)
DNA Virus of _______ is gential herpes, below the waist
Herpes simplex II (HSV-II)
DNA Virus of ______ is only herpes family member that is aerosole transmitted that causes 2 disease in some individual at two different times.
- Young - Chicken pox (doesnt belong to pox family)
- later in life - Causes shingles (zoster)
varicellazoster virus
Virus has ______ which makes virus particle ( interior and exterior) functions in one of the following ways:
- i. attachment
- ii. protecting viral nucleic acid
- iii. modification of host cell
Structural proteins
_______ leads to cancerous, is fusion of infection cell with neighboring non infected cells. infected cells cancerous (unregulated growth and division of infected cells).
modification of host cell
________ unique and aren’t found inside host cell.
Viral enzymes:
______ dependent RNA polymase compare to DNA dependent, RNA polmerase of host cell
RNA
_______ reverse transcription to DNA nucleotid sequence following infection whch integrate the product of reverse transcription into host genomic DNA within 48-72 hours of infection.
viral RNA genome
______: varied functions, some are used to selectively turn on / off viral gene expression
. Viral regulatory proteins
________ others, used to take over host cell and convert into a efficient “factory” for virus production; modulate host defense. infected host cell, theyre not the target or thre not under the radar of the defense cell.
viral regulatory proteins
______ infect all life forms and are responsible for a variety of infectious diseases; can profoundly alter host cell behavior. it can cause the cell to be tumor or cancerous.
virus
We are a reservoir of ___1___ ; they set up residence in gut, lungs, liver.
- our gut is loaded with bacteria harboring their own blend of ___1___
- every one of our cell is infected
- we carry viral genome as part of our own genetic material
1.viruses
_______ plays role in placenta devolop and fusion. they dont make particular
HERV (human endogenous retroviral sequences)
______ transplant into human
PERV (pigs/porcine family)
Porcine endogenous retrovirus genome
____ and ____ recombine to form/evolve a novel virus particle. meaning new virus human never experince (way in the future)
PERV and HERV
8% of our ____ contains these relics of ancient retroviruses
DNA
for virus, ______ can cross species barrier and they do so constantly such as zonotic viruses and rabies virus
viral inection
______ takes residence in metabolically active cells: depends on host cell for energy, transport pathways, protein synthesis, genome replication and assembly. NEVER ON DEAD HUMANS/PLANTS/ANIMALS
viruses
_______ don’t metabolize, respire or grow; they lack basic enzymes for many simple metabolic processes
viruses
_____ lacks structures or appendages for motility. but virus are passively transmitted from one host to another following shedding.
viruses
______ particles are formed by de novo assembly from newly synthesized components within host cell
NO binary fission or mitosis
Virus
______ are not assigned binomial nomenclature (two names) but are grouped into “families”
Example: picorna family which is polio virus a common cold and herpes family
Viruses
_______ smallest virus that infects human
polio virus
______ is the largest virus that inects human
small pox
______ largest virus infect amoeba
mimivirus
________ largest non human virus, infect amoeba
potyvirus
Virus has 3 main shapes, which are ______ is Rod shaped
Ex. Rabies, SARS corona virus
Helical
Virus has 3 main shapes which is ______ shape: spherical appearance
Ex: Papillomaviruses ( HPV
Icosahedral
Virus has 3 main shapes which is ______ (irregular shape) without clear symmetry
Ex: Poxvirus, Retroviruses
Complex particles
_____ contain
Phage genome
- d s DNA
- s s DNA
- s s RNA
Complex viruses
Steps of _____ Replication it’s Attachment: random collision
- weak interaction between tip of tail fiber ( attachment proteins) and specific residues (receptors) on the cell surface
- tail pins on the base plate reinforces the attachment step
Phage
Steps of _____ Replication Entry / Penetration : separation of capsid proteins and genome
Lysozyme degrades cell wall weaken or break PABA
Phage
Steps of ______ replication it’s Lysozyme activation following attachment step results in
- i. compression of tail contractile sheath units
- ii. tube penetrates through cell wall and membrane, tip opens and phage DNA slips through into cytoplasm
phage
Stage of ______ replication has Pilot protein : present at the base of tube that attaches to DNA, guides phage DNA passage into host cell’s cytoplasm
phage
Stage of _____ replication, it’s Synthesis: includes genome replication, transcription and translation
- Incoming phage DNA is transcribed and translated into proteins
phage
Stage of _____ replication its transcription and translation initially uses the host cell RNA polymers viral DNA template.
phage
Stage of phage replication ______ phages induced proteins that are not present in an uninfected cell. that includes viral RNA polymers
early protein
Stage of phage replication, _____ includes capsid proteins (capsomeres) tall components and lyzozyme
late proteins
Replication of phage genome _____ and ____ have Phage protein synthesis and genome replication occurs independently
DNA and RNA
______ when new virus particles are made following infection of host cell
phage productive infection
______ no new virus particle
phage non productive infection
stage of _____ replication, Assembly and packaging complex, orderly sequence of events with self assembly and non enzymatic process
phage
stage of _____ replication, involves capsid and phage genome interaction to form mature, infective phage
phage
______ are used in phage, it doesnt become part of virus particles, it gets degraded with the host cell and viral encoded by late protein.
scaffold proteins
Stage of _____ replication, Release / exit. Lysozyme is synthesized at a later stages of productive infection. Lysozyme breaks / loosens cell wall from inside; cell lysis ensues
- Early synthesis result in non productive abortive infection
phage
_____ and _____ of infection: lyse the host cell they infect
- Burst time: period from entry to release of new virons or pentration
- Burst size: numbers of virus particles released per infected cell 100-500 virus particles
Lytic phage and lytic cycle
______ integration is at specific lotion within host genome that can popout from its own integration site during induction
prophages
_______ integration is random in host DNA, is a permanent phenomeuon, no excision
provirus
Latent State and Temperate Phage Life Cycle
•_______ (lysogenic phages): phage that live in close relationship with host bacterial cells
Temperate phage
Latent State and Temperate Phage Life Cycle
_______: phage DNA incorporated at specific position within host cell DNA; becomes part of the bacterial DNA
Prophage
Latent State and Temperate Phage Life Cycle
______ (lysogen): are prophage carrier cells
Lysogenic cell
Latent State and Temperate Phage Life Cycle
_______ when the prophage “switches” from latent infection to lytic pathway
Phage induction
Latent State and Temperate Phage Life Cycle
•_______: when prophage brings some new trait to the host cell
- Ex: Cornybacterium diptheriae: toxin gene coded by phage genes
Lysogenic conversion
_______ includes virulent that contain prohage that encodes the exotoxin diptheria toxin (eEF2) and avirulent
cornybacterium diptheriae
lysogenic conversion are example of _______ and _______ toxin gene is encoded by prophage
Clostridium botulinum and choleratoxin
lysogenic conversion are example of _______ is exotoxin for scarlet fever coded by phage gene.
Streptococcus pyogenes
______ leads to non productive infection
defective phages
_____ Therapy
Advantages:
- i. prey on bacteria, never human cells
- ii. don’t spread from person to person
- iii. bacteria have trouble becoming immune to them
- eliminate resistance
phage
_____ therapy challeges
Challenges
- iii. phages, recognized as “foreign” by immune system; quickly eliminated
- iv. more detailed animal and human testing needs to be done
phage
_____ therapy challeges
Challenges:
- iii. phages, recognized as “foreign” by immune system; quickly eliminated
iv. more detailed animal and human testing needs to be done
phage
