46-Intro to Medical Microbiology 2 Flashcards Preview

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Flashcards in 46-Intro to Medical Microbiology 2 Deck (63)
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1

What is a virus

Nucleic acid with protein coat
Can have a lipid envelope
Not alive, depend entirely on host cell
Not metabolically active
Smaller than bacteria

2

What is a bacteriophage

Virus that infect and replicate in bacteria

3

DNA in a virus

double stranded, replicates in nucleus

4

RNA in virus

Single stranded, replicate in cytoplasm
Can be positive or negative

5

Positive sense RNA

Ready for translation

6

Negative sense RNA

Requires complementary strand synthesis

7

Lipid envelope

On some viruses
Non enveloped. Viruses are particularly hardy like norovirus

8

virion

Individual virus particle

9

capsid

Proteins associated with nucleic acid

10

capsomers

Individual proteins making up capsid

11

Spike proteins

Specific binding or enzymatic functions
Emerging from capsid of naked virus or membrane of enveloped virus

12

HIV

Reverse transcriptase during replication

13

Shape of capsomers

Helical or spherical (icosahedral)

14

Virus life cycle at cell level

Adsorption
Penetration and uncaring
Synthesis
Assembly
release

15

Virus life cycle at organisms level

Attachment
Spread
Replication
Evasion
transmission

16

adsorption

Interactions between viral proteins and specific host proteins

Have particular tropism

17

Penetration and uncoating

Need to get through cytoplasmic membrane to cytoplasm/nucleus for replication
Enveloped-fuse membrane
Naked-lyse

18

Synthesis and replication

+sense RNA ready to translate
-sense RNA need to generate +sense first
DNA transcribe mRNA

19

Assembly of virions

Helical-capsid proteins form around nucleic acid
icosahedral- capsid assembles and nucleic acid threaded in

20

release

Enveloped-membrane budding
Naked-cell lysis

21

influenza

Enveloped negative sense RNA with 8 genome segments

22

Adsorption of flu

hemagluttinin binds sialic acids

23

Uncoating of flu

Membrane fusion

24

Synthesis of flu

Happens in nucleus, use RNA dependent RNA polymerase to make +mRNA, goes to cytoplasm to make proteins and -mRNA

25

Assembly and release of flu

Virus capsid buds out
Neuraminidase cleanse sialic acid to release virion

26

High mutation rate of RNA virus from RDRP

Help virus evade immunity by causing gradual changes in viral proteins

reason for revaccination every year!

27

Antigenic drift

Gradual changes in viral protiens

28

Antigenic shift

Large changes caused by:
Segmentation of genome
Infection of humans and animals
coinfections

Only type A influenza

29

Immunity to flu

Presence of antibodies against hemaglutanin and neuraminidase

30

sialic acids

Bind hemaglutanin
Human 2-6
Birds 2-3
Pigs 2-3 and 2-6: mixing vessels