MICB 202 Chapter Notes - Chapter Virology: Immunodeficiency, Polyadenylation, Petri Dish

99 views6 pages

sangriamouse716

22 Mar 2016

School

Department

Course

Professor

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

Document Summary

Define what a virus is, describe its basic structures. Viruses not cell differ in 3 ways: they have simple structure, genetic info encoded by. Dna or rna, need assistance of living cell to replicate (are intracellular parasites). Viruses: genetic elements that exist in extracellular (virus particle/virion) or intracellular form. Viral genome surrounded by capsid (protein coat) and sometimes an envelope (lipid bilayer). Capsid and envelope serve to transfer viral genome from one cell to another. Do not have attributes of living organisms other than they reproduce (replicated) and adapt (mutation/variation). Have limited genome size genes carried allow for replication, production of viral structural proteins, and required functions they cannot adapt from host cell: understand terms naked virus, envelope, capsid, and polymerase. All viruses have a capsid and genome. Naked virus: genome enclosed only in protein shell (capsid) (nucleocapsid): replicate, accumulate, then lyse the cell to escape.

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 PrP^C and the pathogenic version PrP^Sc?

PrP^C is just a protein and the PrP^Sc is a protein with nucleic acid inside.

The PrP^C protein contains more beta sheets while the PrP^Sc 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. Unlike Ebola virus, SARS virus
a. has large spikes that look like a âcrownâ.
b. is enveloped.
c. is helical.
d. is in the family Togaviridae.
e. is a ssRNA virus.

2. Which virus or virus family is described in the followingpassage?
Electron micrographs of the hemagglutinin subunits (in the presenceof SDS) showed
rods approximately 40 Ã wide and 140 Ã long. The neuraminidasesubunits had a quite
different appearance. In the presence of SDS, these were seen asoblong structures about 85 Ã long and 50 Ã wide with a centrallyattached fibre 100 Ã long possessing what appeared to be a diffusetail or small knob about 40 Ã in diameter at its end.1
a. Togaviridae
b. Epstein-Barr virus
c. Smallpox virus
d. Orthomyxoviridae
e. Filoviridae
f. Rabies virus

3-Following is a passage from the New England Journal ofMedicine:
______________________ is an exclusively human herpesvirus that ...becomes latent in
cranial-nerve and dorsal-root ganglia, and frequently reactivatesdecades later to produce shingles and postherpetic neuralgia. Inimmunocompetent elderly persons or
immunocompromised patients, ____________________ may producedisease of the central nervous system.
This passage refers to which virus?
a. West Nile virus
b. Smallpox virus
c. Epstein-Barr virus
d. Ebola virus
e. Varicella-zoster virus

4. Pneumoviruses can cause colds and pneumonia in humans. They aresingle-stranded,
negative-sense, nonsegmented RNA viruses. These enveloped virusesare surrounded by an envelope that is characterized by fusionglycoproteins and host-derived proteins. With this knowledge, it islikely that pneumoviruses
a. enter host cells via endocytosis.
b. leave host cells by budding.
c. enter host cells via membrane fusion.
d. A and B
e. B and C

5. Recall that poliovirus is a positive-sense (+) ssRNA virus. The5â Ã ? 3â strand of RNA,
once uncoating has taken place, can serve as an mRNA and encode forviral proteins.
However, in order for the virus to create more +ssRNA to package indaughter viruses, it must
a. generate a dsRNA molecule that can encode for the synthesis ofmore +RNA.
b. integrate into the host cell DNA.
c. utilize an RNA-dependent DNA polymerase to make aheteroduplex.
d. undergo reassortment
e. All of the above

6. Some influenza hosts, such as humans and pigs, cansimultaneously contract human,
avian and swine influenza viruses at the same time. What can occurduring the maturation phase of virus replication in such ahost?
a. Reassortment
b. RNA of all three sources: human, swine and avian, can bepackaged into a single
virion.
c. Genetic shift
d. All of the above

7. The HIV virion contains enzymes/proteins that do all of thefollowing EXCEPT
a. An enzyme that creates âDNA using +RNA as template.
b. A protein that serves as a chemokine receptor.
c. A DNA-dependent DNA polymerase.
d. An enzyme that allows +/- viral DNA to be spliced into the hostcellâs DNA.
e. A protein that mediates membrane fusion.

8. After a long series of biochemical tests, Kyle and Matt werefinally able to identify their Gram-negative unknowns asPseudomonas aeruginosa and Shigella dysenteriae,
respectively. As they compare notes, they realize that theirunknowns are in the
___________ Pseudomonadaceae and Enterobacteriaceae, respectively.However, they also note that both of their unknowns are in the______________ ? proteobacteria.
a. genera, species
b. phyla, family
c. families, class
d. order, phyla
e. classes, order

9-Hydrogenobaculum acidophilum is a resident of YellowstoneâsNorris Geyser basin. This thermoacidophilic microbe grows instringy, white mats and is a member of the phylum Aquificae.Hydrogenobaculum acidophilum
a. could be further researched in Volume 2 of Bergeyâs Manual ofSystematic
Bacteriology.
b. is in the domain Archaea.
c. is a deeply branching bacterium.
d. is a proteobacterium.
e. All of the above

10-After talking about the Group A Streptococci (GAS) and theircapability to sometimes cause a flesh-eating disease callednecrotizing fasciitis, Derek decides to research this group a bitmore. As he reads, he quickly learns that
a. they are microaerophilic Gram-negative rods.
b. they are in the phylum ?-proteobacteria.
c. they are found Volume 4 of Bergeyâs Manual of SystematicBacteriology.
d. they have less than 50 mol % GC content.
e. none of the above

MICB 202 Chapter Notes - Chapter Virology: Immunodeficiency, Polyadenylation, Petri Dish

Document Summary

Get access

Related Documents

MICB 202 Study Guide - Final Guide: Internal Ribosome Entry Site, Viral Envelope, Rna Virus

MICB 202 Chapter Notes - Chapter 1: Dna Virus, Reverse Transcriptase, Orthomyxoviridae

MICB 202 Study Guide - Inactivated Vaccine, Attenuated Vaccine, Reverse Transcriptase

Related Questions