Chapter 19 Flashcards
Viruses & viroids
Not living
Nuclei acid genomes
Viruses are made of
Protin shelf & nuclei acid genome (dna/rna)
1st virus discovered
Tobacco mosaic virus (tmv)
Different host range
Different virus can affect different types of cell
Different structural
Helps infect the host
Capsid
Protein coat
Viral envelope
Part of hosts cell added to virus as a protective layer
Genome
Can have dna/rna,
Attachment
Usually specific virus can attack to specific cell
Entry
Virus DNA gets injected/ The virus fuses with host membrane the entire virus enters
Integration
Cuts host chromosomal DNA & inserts viral genome
Prophase
Stays dormant & May activate later
Reverse transcriptase
RNA to DNA
Provirus
The dormant virus DNA within HOST’S DNA
Sun thesis of viral components
Host cell’s enzymes copy’s makes multiple protein & nucleacic acid of virus particle
Viral assembly
Some viruses self- assembles after viral components are produced.
Release
Virus lives host cell, bacterial cell wall- bacteria burst, enveloped viruses bud from the host cell.
Lysogeny
Latency in bacteriophages
Lysogenic cycle
Integration, replication, & excision
Lyric cycle
Attachment, entry, synthesis, assembly,& release
Temperate
Pages have a lysogenic cycle, environmental condition, influence integration & length of latency
Virulent
Keeps multiplying uncontrollably
Origin of virus
Many Argues cell evolved before virus., others argue viruses evolved in parallel with cellular org.
Virioas
Only random RNA molecule
Prions
Composed entirely of protein that changes shape of other proteins
Bacteria genetic
1 chromosomes found in nucleoid region tightly packed.
Bacterial DNA
2 strands, chromosome usually circular
Bacterial chromosomal
Circular shaped, not wrapped around histone, nucleoside protein forms 100p domains & DNA super coiling (twist)forms.
Plasmids
Small circular pieces of DNAs exist independently of the bacterial chromosome
5 types of plasmids
Resistance plasmids (r factors)- helps resist antibiotic
Degradative plasmids- helps digest & use unusual substance
Col-plasmids- protons that kills other bacteria
Virulence plasmids- turns bacterium into a pathogenic strain
Fertility plasmids- (f factors) - allows bacteria to ”mate” or exchange genetic material
Bateria reproduces by binary fission
Each daughter cell contains identical copy of genetic material, no contribution from parent, cell just divides into 2
Strains
Genetically different forms of same bacteria
2 sources of different strains
Mutations can occur that alter the bacterial genome & affect the traits of bacterial cell,
Genetic transfer
Genetic transfer
Conjugation-direct physical interaction Transfers genetic material from toner to recipients cell
Transformation- DNA released from a dead bacterium into the environment is taken up by another bacteria
Transduction- A virus Transfers genetic information from 1 bacteria to another.
What does donor strains needs to transfer in the recipient
Needs fertility factor
