Covid-19 Flashcards
In the corona-virus, whose full name is “severe acute respiratory syndrome coronavirus (SARS-CoV2), where does the name corona come from?
1 - who identified it
2 - the fact it is an intracellular pathogen
3 - appearance resembling a crown (latin)
4 - all of the above
3 - appearance resembling a crown (latin)
- spike proteins present on cell surface resemble a crown
- latin for crown is corona
In order for an individual to become infected by Covid-19, all 6 steps of the chain of infection model need to be met. Which of the following is NOT one of these steps?
1 - pathogen
2 - the reservoir
3 - portal of exit
4 - origin of pathogen
5 - method of transmission
6 - portal of entry
7 - susceptible host
4 - origin of pathogen
- pathogen = covid-19
- the reservoir = unknown, but can be humans
- portal of exit = respiratory tract
- method of transmission = aerosol droplets
- portal of entry = any orifice
- susceptible host = other people
Once infected with Covid-19, what is the usual incubation period?
1 - 1-3 days
2 - 4-5 days
3 - 7-10 days
4 - 10-14 days
2 - 4-5 days
- can be as long as 14 days though
What are the typical early signs of Covid-19?
1 - New and continuous dry cough
2 - Confusion
3 - Fever >37.8 C
4 - Change or loss of taste and smell
2 - Confusion
Typically occurs in severe Covid-19
Moderate and severe symptoms are in the image
What type of genome is Covid-19?
1 - +ssRNA
2- +ssDNA
3 - -dsRNA
4 - +dsDNA
ss = single stranded
ds = double stranded
1 - +ssRNA
- the fact that Covid-19 is a positive ssRNA means that it foes not need to be transcribed into positive RNA
- +ssRNA can be copied by host cell ribosome straight away
Is Covid-19 an enveloped or non-enveloped virus?
- enveloped
- protects viral DNA/RNA, helps virus evade immunity and facilitates cell entry for the virus
What is the main function of the spike protein located on the Covid-19 virus?
1 - inhibits binding to host cell membranes
2 - binds to host cell membranes
3 - evades immunity
4 - kills T and B cells
2 - binds to host cell membranes
Covid-19 is described as zoonotic. What does zoonotic mean?
1 - virus is only found in zoos
2 - virus is only found in humans
3 - virus originated in animals
4 - virus mutated between animals and humans
3 - virus originated in animals
- think zoo and think animals
The S or spike protein located on the corona virus has been linked with what enzyme, and the associated symptoms of Covid-19?
1 - angiotensin-converting enzyme 2
2 - creatine kinase
3 - lactate dehydrogenase
4 - gluconeogenesterase
1 - angiotensin-converting enzyme 2
Covid-19 is a +ssRNA. What does the positive relate to?
1 - signifies virus is inside the cell
2 - identifies that the RNA is actually mRNA
3 - signifies the virus has not infected the host
4 - identifies that the RNA needs to be processed before entering the host DNA
ss = single stranded
2 - identifies that the RNA is actually mRNA
- this is important as it can be copied immediately by the ribosome in the cell
- important for infection so proteins can be produced
Which part of the Covid-19 contains the RNA genome of the virus?
1 - S protein
2 - N protein
3 - Membrane protein
4 - Envelope protein
2 - N protein
Called the Nucleocapsid (N) protein
Covid-19 contains a nucleocapsid (N) protein. In addition to being a structural protein, what other functions does it have?
1 - helps bind to cell membranes and manipulate cell cycle
2 - helps infect cells and manipulate cell cycle
3 - assembly, transcription of proteins and manipulate cell cycle
4 - kills T and B cells and manipulate cell cycle
3 - assembly, transcription of proteins and manipulation of the cell cycle
Covid-19 contains a nucleocapsid (N) protein. In addition to being a structural protein it is also involved in assembly, transcription of proteins and can manipulate the cell cycle. The N protein has also been described as a Viroporins. Viroporins are small virally encoded hydrophobic proteins that oligomerize in the membrane of host cells, loosening of tight junctions and leading to the formation of hydrophilic pores. Why is this important in Covid-19?
1 - allows covid-19 to form granulomas and go undetected
2 - allows covid-19 to spread beyond epithelial basement membranes
3 - allows covid-19 to induce malignancies and increase VEGF
4 - all of the above
2 - allows covid-19 to spread beyond epithelial basement membranes
- means the virus can easily spread
The Covid-19 virus has 2 domains, which are areas of a protein that have a unique function, which is where the name S1 and S2 of the spike protein come from. This is important as this is how Covid-19 has been shown to bind with and infect the host. Is it the S1 or S2 domain that is involved in the interactions with angiotensin converting enzymes-2?
- S1
- protein must be in the up conformation for this to work
The Covid-19 virus has 2 domains, which are areas of a protein that have a unique function, which is where the name S1 and S2 of the spike protein come from. This is important as this is how Covid-19 has been shown to bind with and infect the host. Is it the S1 or S2 domain that is involved in the interactions with host cells leading to infection?
- S2
There are specific parts of the spike 1 protein that facilitate binding to ACE2 in the up confirmation. Using the labels below, label the parts of the spike 1 protein:
- receptor binding motif
- human ACE2
- receptor binding domain
1 - human ACE2
2 - receptor binding motif
3 - receptor binding domain
What is glycan shielding in terms of Covid-19?
1 - gylcans bind immune cells and render them inactive
2 - glycans replace the antigen altogether
3 - glycans are added to virus to hide antigens
4 - glycans release cytokines that are anti-inflammatory
3 - glycans are added to virus to hide antigens
- if no antigens are visible the immune cells cannot target the cell
Anti-genetic drift is the accumulation of random or stimulated mutations over time due to selective pressures for survival, specifically to regions where antibodies would bind. In terms of Covid-19 virus, where would there be the location for mutations to occur?
1 - N protein
2 - M protein
3 - S protein
4 - Envelope protein
3 - S protein (specifically the S1 domain)
- constant mutations ensure antibodies cannot effectively bind
- ensure the virus is very difficult to kill
Glycan shielding is where the virus adds glycans to its structure to hide the S1 domain of the spike protein from antibodies and thus hide the antigens. If no antigens are visible the immune cells cannot target the cell. What can host immune system do to try and tackle this problem?
1 - produce pentraxins (CRP) to bind with glycans
2 - produce ficolins to bind with the glycans
3 - produce mannose binding leptin protein (MBL-P)
4 - produce T cells able to bind sugars
3 - produce mannose binding leptin protein (MBL-P)
- the sugar mannose is present on the glycans on the S1 domain
- MBL-P can bind and active the complement system
- produce membrane attack complex, opsonisation and agglutination
There are specific parts of the spike 1 protein that facilitate binding to ACE2 in the up confirmation. The 3 parts of the spike 1 protein are
- receptor binding motif
- human ACE2
- receptor binding domain
Which part of this structure do antibodies target?
- receptor binding domain
Bind to ACE receptors throughout the body, BUT predominately affects the upper and lower respiratory tracts
