🏷️ LIMITED TIME OFFER: GET 20% OFF GRADE+ YEARLY SUBSCRIPTION →
Log in
HomeClass Notes1,200,000CA670,000

MGY378H1 Lecture : 04 - corona - notes.docx

52 views6 pages
redtermite204
25 Apr 2012
School
UTSG
Department
Molecular Genetics and Microbiology
Course
MGY378H1
Professor
Alan Cochrane

For unlimited access to Class Notes, a Class+ subscription is required.

Document Summary

Bev= berne virus, prototype bovine toroviruses were found to play a role in respiratory, digestive, and reproductive disorders of cattle. Tgev=transmissible gastroenteritis virus (tgev), a major pathogen causing a fatal diarrhoea in newborn pig. Crown look b/c optical slice through virus. Architectures of virus particles of the prototype nidovirales members. Shown are cartoons depicting possible organizations of a coronavirus [21]. D ronivirus (modified from an scheme by peter walker, indooroopilly, Australia [75]) virions as deduced from available results. E, envelope protein; s, spike protein; he, hemagglutinin-esterase; gs, small glycoprotein; Based on genome sequences and antigenic relationships coronaviruses fall into 3 groups. First identified in 60s induce 30% of colds in population colds can be used by rhino or coronaviruses. Procin, bovine, avian coronaviruses attack agriculture, livestock. Common cold limited mortality so little interest in coronavirus until sars. Sars first example of coronavirus with significant pathogenicity in humans.

Get access

Grade+20% off
$8 USD/m$10 USD/m
Billed $96 USD annually
Grade+
Homework Help
Study Guides
Textbook Solutions
Class Notes
Textbook Notes
Booster Class
40 Verified Answers
Class+
$8 USD/m
Billed $96 USD annually
Class+
Homework Help
Study Guides
Textbook Solutions
Class Notes
Textbook Notes
Booster Class
30 Verified Answers

Related Questions

2.)

a.) Are viruses that infect Archaea different from other bacterial viruses?

Yes, they do not have protein coats because of the extreme conditions where they live.
No, they consist of nucleic acid and protein just like other bacterial viruses.
Yes, the structure of archaeal viruses is always completely different from other bacterial viruses.

Yes, they have only DNA genomes.

b.) Of the following examples, which is not a common part of many viral life cycles?

The pox virus genome is replicated by DNA polymerase.
Adenoviruses attach to the cell and the nucleocapsid is taken up by the cell.
Pox viruses replicate in the cytoplasm of the cell.

Once an adenovirus virion is inside a cell, host RNA polymerases transcribe early genes

c.) Some viruses are associated with cancer. There are a variety of ways in which viruses may affect a cell in a way that may lead to cancer. Based on your knowledge of the life cycles of viruses and of molecular genetics, what is one way that this might happen?

Viral genetic material inserts into a host genome close to the termination sequence, far downstream of the promoter, and causes a silent mutation.
Viral genetic material inserts into a host genome in a repetitive noncoding region.
Viral genetic material inserts into a host genome, placing a promoter in a new location and turning on a gene that had previously been turned off.
Viral genetic material inserts into a host genome and causes a mutation in a promoter, turning off a gene that had previously been turned on.

d.) Which statement describes the difference between the normal neuron protein PrPC and the pathogenic version PrPSc?

PrPC is just a protein and the PrPSc is a protein with nucleic acid inside.
The PrPC protein contains more beta sheets while the PrPSc protein contains more alpha helices.
The three-dimensional conformation is identical, but the amino acid sequence is different.
The amino acid sequence is identical, but the three-dimensional conformation is different.

1. A mutation in the gene encoding the integrase enzyme rendersthe protein non-functional. How would the affect the HIV infectioncycle?

Formation of the provirus would bestopped.
Reverse transcription would nolonger be possible.
The gp120 glycoprotein would nolonger be able to bind to the CCR5 receptor.

Cutting and assembling the capsid would be halted.

2. If the viral gene is AUGCCCAGG and the mRNA used to make theviral protein is UACGGGUCC, then the virus is a :

Negative strand RNA virus
Double stranded DNA virus
Retrovirus

Positive strand RNA virus

3. Would treating prions with enzymes that digest nucleotides bean effective neutralization method?

No, prions lack amino acids.
Yes, prion nucleic acids would besusceptible to enzymatic digestion.
No, prions lack phosphodiesterbonds and would not be subject to digestion by these types ofenzymes.

Yes, the bonds between the amino acids would be hydrolyzed.

4. Most Americans born before 1970 have a permanent scar ontheir shoulders from the smallpox vaccine. Why don't youngerAmericans have one?

Smallpox has been eradicated by aworldwide vaccination program.
Smallpox is no longer lethal.
A safer less damaging vaccine wasdeveloped in the early 1970's.

The vaccine is no longer effective due to antigenic shift.

5. What kind of pathogen would retain its ability to causeinfections after being treated with powerful proteolytic chemicalsthat would destroy all proteinaceous material?

A virus
A bacterium
A prion
A fungus

A viroid

6. Select all of the false statements concerning AIDS.

AIDS kills the patient.
Patients die as a result ofopportunistic infections.
AIDS shuts down the immunesystem.
HIV therapy (HAART) can clear thevirus from the bloodstream.

HIV therapy (HAART) can clear the virus from the patient'sbody.

7. Why do viruses only infect specific types of cells?

Viruses only attack epithelialcells, such as the cells lining the lungs.
If a host cell is weakened, viruseshave an easier time infecting it.
The initial choice is random butonce a cell type is chosen it becomes the preferred host.
The host cells have the correctsurface receptor that the virus can fit into.

Viruses infect the first cells they encounter.

8. Nucleotide analogs are a class of drugs that are highlyeffective against many types of viruses. They work by halting thereplication of viral genes. They are equally effective at stoppingthe spread of prion diseases.

True

False

9. An experimental chemical has been shown to selectively cleavephosphodiester bonds. How would the affect a virus?

Dissociate the envelope
Fragment the genome
Hydrolyze the protein coating
Alter the host binding site

Digest the capsid

10. HIV uses cell surface receptors to enter host cells. Whydoes switching from a CCR5 co-receptor to a CXCR4 co-receptoreventually shut down the immune system?

Macrophages have CCR5co-receptors.
T-helper cells have CXCR4co-receptors.
T-helper cells are not involved incoordinating immune responses.
Only macrophages are killed byHIV.

42. Which of the following bacteria that may cause meningitis is Gram-positive and therefore does not cause endotoxin shock in infected individuals?

Escherichia coli

Neisseria meningitidis

Listeria monocytogenes

Haemophilus influenzae type B

None of these

43. Viral meningitis is usually always fatal if untreated, unlike bacterial meningitis, which is always self-limiting and nonfatal. True or false?

44. Which of the following is acid-fast and causes Hansen's disease?

Mycobacterium tuberculosis

Clostridium tetani

Neisseria meningitidis

Haemophilus influenzae

Mycobacterium leprae

45. An immunofluorescent antibody test (IFAT) has replaced the older test for the presence of inclusions in neurons (Negri bodies) for the detection of infections caused by:

Neisseria meningitidis

Enteroviruses

Mumps virus

Rabies virus

Haemophilus influenza

46. The viruses that cause encephalitis are most likely to be:

Togaviruses

Enteroviruses

Mumps virus

Rabies virus

Hepatitis viruses

47. The only bacterium known to damage peripheral nerves is:

Naegleria fowleri

Mycobacterium leprae

Streptococcus pneumoniae

Neisseria meningitidis

Haemophilus influenzae

48. The endospores of this organism are the most heat-resistant known; it is:

Clostridium tetani

Clostridium botulinum

Mycobacterium leprae

Streptococcus thermicos

Listeria monocytogenes

49. All of the following are true about poliomyelitis EXCEPT:

Most poliovirus infections are inapparent or mild and nonparalytic.

Polio can be caused by three strains of picornaviruses.

The Salk vaccine contains live, attenuated polioviruses while the Sabin vaccine contains formalin-inactivated polioviruses.

Transmission is by the fecal-oral route and pharyngeal secretions.

Poliomyelitis has afflicted man for thousands of years.

50. Which of the following stains is used frequently to identify Mycobacterium and other bacteria whose cell walls contain high amounts of lipids?

Gram stain

Schaeffer-Fulton stain

Acid-fast stain

Lipidialar stain

Spore stain