Virus

Question 1

Hvad er en virus?

Answer 1

Sup-mikroskopisk non-cellulær genetisk element
Afhængig af andre organismer for replikation
Obligat parasit
Frit ekstra-cellulært stadie
Arvemasse er nukleinsyre

Question 2

Størrelsen af virus partikler

Answer 2

Der kan være mere end 500 virus partikler inde i en bakteriecelle

Question 3

Pandoravirus

Answer 3

Base pairs: 2.5 million

Length: 1000 nm

Diameter: 500 nm

Question 4

Megavirus chilensis

Answer 4

Base pairs: 1.26 million

Diameter: 500 nm

Question 5

Influenza type A

Answer 5

Base pairs: 13500

Diameter: 100nm

Question 6

Opdeling efter vært

Answer 6

Dyre-virus

Plante-virus

Bakterie-virus eller bakteriofag

Question 7

Virus opbygning

Answer 7

Nukleinsyre

Kapsid

Enzymer

Membran

Question 8

Nukleinsyre

Answer 8

DNA eller RNA

Enkelt eller dobbeltstrenget

2kb - 200 kb (2500kb)

4 gener -&raquo_space;100 gener (>2000)

Question 9

Morfologiske typer - kapsider

Answer 9

Icosahedral
Rørformet
Membran omsluttet
Komplekse

Question 10

Kapsomer

Answer 10

Polymer af en eller flere protein enheder

Question 11

Rørformede virus kapsider

Answer 11

Formet som et hult rør med en protein væg

Question 12

Icosahedral virus kapsider

Answer 12

Icosahedron er en rumlig struktur med 20 trekantede sider

Question 13

Komplekse virus kapsider

Answer 13

Influenza virus
Kobbe virus
T4 bakteriofag

Question 14

Membran - virus

Answer 14

Almindelig ved dyrevirus
Lipid dobbeltmembran kommer fra værtsorganismen
Der forekommer ofte virus specifikke membranproteiner

Question 15

Kapsid størrelse

Answer 15

Afhænger til dels af genomtype og størrelse

Question 16

Enzymer - virus

Answer 16

Polimeraser
- MS2

Revers transcriptase
- Retrovirus

Lysozymer

Question 17

Detektion af virus

Answer 17

Plaque
- Analog til bakterielle kolonier
- Titer (antal) betsemmes som plaque forming units - PFU

Question 18

Direkte tælling af virus

Answer 18

Direkte tælling i elektron mikroskop EMS
- “efficiency of plating” angiver hvor mange fag partikler som kan give plaques.

Question 19

Virulent livscyklus

Answer 19

1) Attachment (adsorption)
2) Penetration (injection)
3) Synthesis of nucleic acid and protein
4) Assembly and packaging
5) Release (lysis) of mature virus particles

Question 20

Virus fasthæftning til cellen er specifik

Answer 20

Bakteriofager inficere derfor typisk kun en bakterieart

Dyrevirus inficere ofte kun specifikke vævstyper

Question 21

Coronavirus - SARS-CoV-19

Answer 21

Enkelt strenget
+ RNA virus

Question 22

Den lysogene livscyklus

Answer 22

1) Attachment of the virus to the host cell
2) Injection of viral DNA
3) Viral DNA is integrated into host DNA
4) Viral DNA is replicated with host DNA at cell division
5) Induces the lytic pathway
6) Phage components are synthesised and virions are assembled
7) Lysis of the host cell and release of new phage virions

Question 23

Retrovirus livscyklus

Answer 23

1) Entry and uncaring of the retrovirus
2) Reverse transcriptase activity (two steps)
3) Viral DNA enters nucleus and integrates into the host genome
4) Transcription by host RNA polymerase froms viral mRNA and genome copies
5) Translation of mRNA forms viral proteins; new nucleocapsids assembles and released by budding

Question 24

Andre infektiøse elementer

Answer 24

Plasmider
- Cirkulære DNA molekyler

Viroider
- Små cirkulære enkelt strengede RNA molekyler 250-375 nucleotider

Prioner
- kun protein