1 Virus: Introduction Flashcards
6 Atom components of viruses + 1 fact with example
carbon
hydrogen
nitrogen
oxygen
phosphorous
sulfur
→ some viruses can be written as chemical formula like Polio
Components of Viruses
Capsid
→ protein shell of virus, consists of several oligomeric structural subunits made of protein called protomers
Nucleocapsid
unit of viral structure, consisting of capsid with enclosed nucleic acid
Envelope
→ optional, derived from host cell membrane
→ e.g. HIV, SARS, Influenza
Name at least 8 of these viruses
links oben: Adenovirus
links mitte: Ebola
oben mitte links: Bacteriophage
oben mitte rechts: Corona
mitte mit Einkerbung: HIV
bullets: Rabies
rechts unten: Influenza
rechts oben: Smallpox
rechts Mitte: Polio
Mitte: Pandora
unten mitte: Amoebae virus
unten links: Tabacco Mosaik virus
Size of Virus ?
What can be used to detect virus ?
Size of E.coli, RBCs, ribosom, Polio, Smallpox
Size: 10^(-7)
Detection with electron microscope (or x-ray)
Virus strategy to exists (3P)
All viruses package genome inside particle used for transmission of the genome from host to host
viral genome contains the information to initiate and complete an infectious cycle within host/cell
All viral genomes are able to establish themselves in host population to ensure existence
Virus defintion (3P)
How many virus isolates? (1P)
→ infective agent that typically consists of nucleic acid molecule in protein coat
→ able to multiply only within living host cell
→ to small to be seen via light microscopy
> 40.000 virus isolates
Virion
→ defintion (1P) and components (4P)
→ complete infectious particle
RNA/DNA
protein shell
capsid/nucleocapsid
envelope
Satellite Virus
example (1/1P), characteristics (7P)
special about Virophages? (2P)
subviral agent composed of nucleic acid that depends on co-infection of host cell with helper/master virus for replication
→ capsid protein coat
→ requires host and helper/master virus
→ transmitted independently
→ plants/mammals
e.g. Hepatitis D with master virus Hepatitis B
Virophages
→ giant helper virus e.g. Megavirus
→ dependent transmission (transmitted within helper virus) e.g Sputnik Virophage
Viroid
→defintion (1P), characteristics (3P)
→ where found and what does it require ? (1/1P)
very small pathogens consisting of short strands of circular, ssRNA without protein coat
→ no genes, no protein coat and no envelope
found in plants and requires plant replicase
Transposon
→ defintion (1P), DNA (4P)
found where ? (1P)
e.g. (1P)
DNA sequence that can change position within genome, creating/reversing mutations and altering cells genome size
DNA:
→ variable size
→ may contain genes
→ no protein coat
→ no envelope
found in eukaryotic cells
e.g. endogenous retroviruses
Prion
→ defintion (1P) and examples (3P)
Just a protein in mammals that replicates by protein folding, one misfolded proteins (PrP-C) leads to misfolding of many other proteins (PrP-SC)
e.g. Scrapie in sheep, BSE in cows or Creuzfeldt Jakob Disease in humans
Example for virus as key driver of evolution (2P)
special fact about human genome and viruses
Placenta in mammals
→ Syncytin, derives from endogenous retrovirus drives placental/uterine interface fusion
8% of human genome is viral offspring
Virus infections can be … (3P)
asymptomatic (commensal)
disease causing (pathogenic)
beneficial (mutualistic)
→ attack tumor cells like Herpesvirus that arm natural killer cells or Measles Viruses that bind to receptor present on tumor cells
First viruses discovered in animals and humans ? (2P)
human: Yellow Fever Virus
animal: Foot and Mouth disease Virus
Virus that are used as tool in lab (2P)
Flock house Virus is an insect virus that infects many experimental hosts
Bacoluvirus is an insect virus used for mammalian protein synthesis
