Unit 1: 6.2 Flashcards
What is the lytic cycle?
Bacteriophage takes over cell reproduces new phages and kills the cell
What are the stages in lytic cycle?
- Attachment
- Penetration
- Biosynthesis
- Maturation
- Lysis
Attachment
Phage attaches to surface of host
Penetration
Viral DNA enters the host cell
Biosynthesis
Phage DNA replicates band phage proteins are made
Maturation
New phage particles are assembled
Lysis
Cell lyses releasing the newly made phages
What is the lysogenic cycle?
Phage integrates into host genome
What is the integrated phage genome called?
Prophage
Lysogeny
Process where a bacterium is infected by a temperate (inactive) phage
Latency
Happens in animal viruses which is similar to lysogeny in bacteriophage
How do bacteriophages infect host cells
Inject their dna
How do animals have infect host cell?
Endocytosis or membrane fusion
Generalized transduction
When a random piece of bacterial chromosome DNA is transferred by page during lyric cycle
-can cause antibiotic resistance or sugar metabolizing gene
Specialized transduction
Happens at the end of lysogenic cycle when prophage leaves cell and the bacteriophage Emeterio the lyric cycle
What happens if a virus has +ssRNA genome
It can be translated to make viral proteins acts as mRNA
What happens if a virus has -ssRNA genome?
Host ribosomes cannot translate it until it turns positive
Retroviruses
+ssRNA viruses that have reverse transcriptase which can turn +ssRNA into dsDNA and become a permanent part of the host
Provirus
Integrated viral genome form retroviruses
What genome do plants have
+ssRNA no DNA genome
Persistent infections
When a virus is not completely cleared from the system but stays in certain tissues or organs of infected person
Latent viruses
Cause an acute infection before becoming dormant and are difficult to detect
-ex: chicken pox causes shingles later
Chronic infection
When body cannot eliminate the virus, makes a chronic infection after a long period of latency
- affect the immune system
- ex HIV
What kind of growth curve do bacteriophage have?
One-step multiplication curve
What are rogue forms of the protein Prp
Prions
What infectious agents do not have a nucleic acid?
Prions
Virulent phages
Lead to the death of the cell through cell lysis
Temperate phages
Become part of the host chromosome and are replicated with genome and make progeny viruses
