Exam 3 Flashcards
How do we describe the general size of viruses vs bacteria?
Typically, viruses are smaller than bacteria
Do viruses have cells?
No they only have a genome surrounded by a protein coat
What was the first virus to be characterized?
Tobacco Mosaic Virus
What is a virion?
the complete virus particle (protein coat and genome)
What is a capsid?
The protein coat
What is a capsosmeres?
The particles that makeup the capsid
What are complex viruses?
Any virus that has more than just the normal protein coat and genome
Protein spikes are only present in?
Complex viruses
How do protein spikes relate to host specificity?
Because other cells have receptors to these spikes
What is narrow host specificity?
Affecting an organ
What is broad host specificity?
Affecting the body
What is adsorption?
It is step one of the viral infections process and it is when the virus comes into contact with the host cell and fuses through its plasma membrane
What is penetration?
The second step of viral infections and it is when the virusinjects genetic material inside the cell or when a virus is taken up by host cells (both ways)
What is uncoating?
If virus passed stage 2, the viruses will be uncoated and the viral genome is directing the host cell
What is synthesis?
4th step of viral infections and it is when the bacteria (taken over by virus) begins to make new genetic material and capsosmeres
What is assembly?
5th step of viral infections. Once all the materials for viruses are created, we have to assemble them to create virions
What is the final step of the viral infections processing?
The virus that has invaded the host cell is released through lysis and pick up some of the cells membrane to hid/act as a host cell
What are the different genome possibilities that a virus can have?
ssDNA, ssRNA, dsDNA, dsRNA
In order for viruses to go against central dogma, what must they have?
The enzyme reverse transcriptase
What is lytic life cycle?
When a virus infects and takes over the host cell, manipulates it to make new viruses and bursts out
What is lysogenic life cycle?
When a virus takes over the host cell but instead of bursting, it gets out of the nucleus and inserts its genome into the existing host genome
How is viral genome unpackaged in host cell?
It is converted to RNA so that enzymes can replicate the genomes to make new viruses.
What is cytopathic effects?
A term used to describe virus induced advantage
Viruses with reverse transcriptase are referredto as ________
Retroviral virions
What is an acute infection?
Where there is one infections and a distinct beginning and end
What is a latent infection?
This is when there is an acute infection but it doesn’t end, the virus simply hides
What is a chronic infection?
When the virus never really goes away, slightly reduced
What type of viral infection is human papilloma virus?
It is latent infection
What type of viral infection is herpes?
It is an acute viruse that goes latent and then acute
What type of viral infection is ebola?
It is an acute infection
What are prions?
A prion is an infectious protein. These prevent other proteins from forming properly and causing them to not function properly
What are prion infections caused by?
Consumption of abnormal protein or gene mutations
What is human microbiota?
All of the microbes living on or in the human body
How does an infection turn into a disease?
When it begins to compromise the function of our body
What are the 5 requirements that a microbe needs to cause infection?
- Reservoir
- Host, portal of entry and adherence
- Cause infection through multiplication
- Hide from host’s immune cells
- Has to leave through portal of exit
What are the different ways a microbe can be transmitted?
Direct contract Indirect contact Aerosolized Food/water transmission Vector Vertical (mom to baby)
What are the main portals of entry?
Respiratory system, digestive system, urethra, skin, vagina, penis, placenta
What is our first line defense?
Skin
What is ID 50?
Infectious dose is the potential effectiveness of an organism. ID50 refers to the minimum amount of microbes that are required to be transmitted for infection (50% of the population)
What does a lower ID 50 indicate?
It means it is more infectious because it requires less organisms to cause an infection
What is LD50?
It relates to how many cells can cause death in 50% of the population
What microbial anatomy functions can allow microbes to adhere once inside the cell?
Glycocalyx (sticky layer)
Fimbriae
Suckers
receptor activation
What is incubation period?
The time between exposure to microbes and the onset of system