Structures
Job of the capsid?
Protects viral genes
Made of capsomeres
In all viruses
Why is uncoating necessary?
The capsid protects and covers viral DNA or RNA. The virus must break down the capsid layer to free genetic material and take over the host.
How do 'naked' cells leave the host?
Lysis
What are the 2 bacteriophage life cycles?
Lytic and Lysogenic/Temperate
Why do we culture viruses?
Prepare vaccines, isolate samples for clinical studies, better understand viral structures/genes/replication
What is the envelope made of?
This is a optional outer layer that surrounds the whole virus and is made of stolen host parts (our lipids)
How do enveloped cells leave the host?
Budding
Wild Card: bet?
Who is the 'father of aseptic technique'?
Do bacteriophages need to uncoat in the lytic life cycle?
No, their complex viral structure directly injects genes into the host.
Looking at a sample of lung tissue, we see that the patient's cells have started to fuse as a direct result of viral damage. This is what viral effect?
Cytopathic Effects (CPEs)
Are viruses cells?
No, they can never have both DNA and RNA and have no independent metabolism.
What is host range.
The number of hosts a virus can infect, usually 1.
Covid-19: humans (1)
Swine Flu: pigs and humans (2)
Animal viruses target what host?
Eukaryotes (animals, like people)
How are viruses released in the lytic cycle?
Lysis: host cell (bacteria) pops open
Example of a virus that stays dormant in the human body?
Herpes
Chicken Pox/Shingles (varicella Zoster Virus)
Job of glycoprotein spikes
Allow virus to find and stick to hosts like a key and lock
Wild Card: bet?
A macroscopic mass of bacteria we can see is called a _____________.
Why can only enveloped viruses do membrane fusion to enter a host cell?
Only enveloped viruses have an extra membrane layer (the envelope) they can use to fuse with the cytoplasm membrane of an animal host cell.
Do the lytic and lysogenic life cycle start the same way?
Yes
Adsorption > Penetration > Taking over host genes > then they act different
Hepatitis causes liver cancer making it a(n) ______________?
Oncovirus
True or False: Viruses can have DNA and RNA.
False, Never Both. (Only one, "or" is key)
3 main steps of assembly:
1. DNA or RNA is made
2. Capsid is formed and DNA/RNA covered
3. Spikes are picked up from the host membrane (either by lysis or stealing it)
In synthesis, the virus takes over which metabolic pathway? (There are 2, they make proteins)
Transcription and Translation
What is lysogenic conversion?
A stable long-term relationship between the phage and its host in which the phage DNA becomes incorporated into the host genome
We work with E. coli in contained petri dishes with no live animal application. This is what type of research?
In vitro