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Flashcards in viral genetics Deck (38)
1

viral genome

may consist of double or single stranded DNA, double or single stranded RNA

2

capsid

protein shell enclosing the viral genome built from capsomeres

3

viral envelope

surrounds the capsids and is derived from the membrane of the host cell; contains host cell membrane proteins and phospholipids

4

bacteriophage

viruses that infect bacteria and have the most complex capsids

5

RNA viral genes

include specialized virus encoded polymerase that use RNA as a template

6

lytic cycle

last stage of infection, where bacterium lyses open and releases phages produced within cell

7

virulent phage

bacteriophage that reproduces only by a lytic cycle

8

lysogenic cycle

replicates the phage genome after the viral genome enters by genetic recombination

9

temperate phage

phage capable of using both lysogenic and lytic cycle for replication

10

prophage

after being integrated into the bacterial chromosome the viral DNA is a prophage that blocks transcription of viral genes

11

enveloped viruses

not all viruses have envelopes; reproductive cycle that allows virus to export and infect other cells without lysing cell

12

retrovirus

RNA animal virus equipped with the enzyme reverse transcriptase; HIV is retrovirus

13

provirus

integrated viral DNA from reverse transcriptase that does not leave the hosts genome

14

vaccines

harmless variants or derivatives of pathogenic microbes that stimulate immune response

15

viral horizontal transmission

a plant is infected from an external source of the virus

16

viral vertical transmission

plant inherits a viral infection from a parent

17

viroid

circular RNA pathogenic molecules; only several hundred nucleotides long, that infect plants

18

prions

infectious proteins which appear to cause a number of degenerative brain diseases

19

prion transmission

misfolded protein that induces the correct protein upon contact to assume the incorrect shape

20

transformation

uptake of naked, foreign DNA from the surrounding environment in bacteria capable of natural transformation or induced

21

transduction

phages carry bacterial genes from one host cell to another after incorrect insertion of bacteria DNA into phage

22

conjugation

direct transfer of genetic material between a bacteria with F factor and another bacteria

23

plasmid

small, circular, self replicating DNA molecule separate from bacterial chromosome

24

episome

temperate viruses; genetic element that can replicate either as part or independently of bacterial chromosome

25

transposable element

unlike plasmid or prophage, always part of chromosomal or plasmid DNA

26

insertion sequence

contains only the single gene transposase which recognizes inverted repeats

27

transposon

includes inverted repeats with transposase gene which sandwiches another or multiple genes

28

bacterial operator

controls the access of RNA polymerase to the genes near the promoter

29

operon

the operator, the promoter, and genes they control

30

bacterial repressor

binds to the operator and blocks attachment of RNA polymerase to the promoter

31

corepressor

small molecule that cooperates with a repressor protein to switch an operon off

32

DNA Polymerase III

synthesizes DNA in leading and lagging strand for bacteria

33

DNA Polymerase I

removes RNA primers and fills in with DNA

34

bacteria chromosomes

most bacteria contain circular chromosomal DNA and one chromosome with few million bp

35

bacterial OR

several thousand different genes and one bidirectional origin of replication

36

bacterial DNA compaction

DNA must be compacted 1,000 fold

37

bacterial primosome

DNA helicase+primase

38

bacterial replisome

2 DNA polymerase holoenzymes+primosome