MICR 2340 Lecture Notes - Lecture 11: Rna Virus, Lipoprotein, Cytopathic Effect

77 views2 pages

indigocaribou704

15 Oct 2016

School

Department

Course

Professor

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

Document Summary

Slide 12- two types of capsid symmetry, helical where the virus is protected by structural subunits called capsomers and icosahedrical symmetry like the adenovirus where the virus is protected by a structure. Slide 13- viral genome is classification we use the most. Inside capsid can only have rna or dna not both. It is important to know how the virus multiplies. The cell has dna, double stranded if we want to make more to have more cells we use replication need template dna dependent dna polymerase. If you want to make proteins from the genetic information need rna (transcription) you need dna dependent rna polymerase. This is what a virus wants to do to assemble more viruses. Because it needs this process to make more viral genome and proteins. Single stranded rna virus, positive (similar to messenger rna) to do genome replication you start with rna (need dna dependent rna polymerase) and you only need rna multiplication.

Related Questions

QUESTION 1: The rabies virus primarily affects the nervous system. The specificity that the rabies virus has for neuronal host cells is primarily dictated by __________________________.

A. the helical shape of its viral capsid

B. the type of nucleic acid used for its viral genome (single-stranded, antisense RNA)

C. the spikes that protrude from its viral envelope

D. the segmented nature of its viral genome

QUESTION 2: Which of the following genome types has been observed in viruses? To be marked correct, you'll need to select all true statements, as there may be more than one correct answer.

A. Single-stranded RNA

B. Single-stranded DNA

C. Double-stranded RNA

D. Protein-based

QUESTION 3: Choose the correct statement about viral evolution.

A. RNA and DNA viral genomes evolve at equal rates.

B. Cellular genomes mutate at a faster rate than viral genomes due to their large size and increased chance of replicative mistakes.

C. DNA viruses mutate faster than RNA viruses because thymine is more susceptible to mutation than uracil.

D. RNA viruses mutate faster than DNA viruses due to a lack of proofreading replicative enzymes.

QUESTION 4: Your elderly patient is affected by shingles. After careful observation, you note that the virus responsible for the infection has an icosahedral capsid, is enveloped, and has double-stranded linear DNA as its genetic material. Based on this information, in which of the following viral families would you group this viral pathogen?

QUESTION 5: Which of the following is a key difference between lytic and lysogenic bacteriophage replication cycles?

A. Lysogenic bacteriophages release via host cell lysis, whereas lytic bacteriophages bud off from the host cell membrane.

B. The lytic replication cycle ends with host cell lysis and release of newly formed bacteriophage particles, whereas lysogenic replication leads to prophage formation.

C. Lytic replication requires an uncoating step, whereas in lysogenic replication, the bacteriophage's nucleic acid is directly injected into the host cell.

D. Whereas lytic replication enables the infection of several hosts, lysogenic replication only allows for infection of a single host cell.

QUESTION 6: Which of the following is an unsuitable culture method for an animal virus?

A. Direct inoculation of virus onto blood agar

B. Live animal inoculation

C. Tissue culture method

D. Injection of virus into embryonated eggs

Below is a paragraph describing HIV infection as they relate to the progress of infection. Please help choose the correct answer in each parentheses.

HIV initially infects (CD4+, or CD8+, or B) cells. These are helper T cells that activate (CD4+ or ,CD8+ or, B) cytotoxic T cells and (CD4+, or CD8+, or B) cells which produce antibodies. If HIV kills (CD4+, or CD8+) T cells then they cannot to do their job of activating these cells thus causing HIV infected people to be immunocompromised. Sometimes HIV infected people enter a latency period where the virus is inactive. This latency period can last for several years. During latency HIV (DNA, or RNA) becomes integrated into the (CD4+ or CD8+, or B) host cells genome and stops producing viral HIV RNA and new HIV virions. However, for some unknown reason, HIV comes out of dormancy and the viral (RNA, or DNA ) that was integrated in the (CD4+ , or CD8+,) T cell genome begins to transcribe more viral (DNA , or RNA) to make more viral (DNA, or RNA) using the host cells machinery. The viral (DNA, or RNA) then gets translated by host cell ribosomes to make viral proteins that eventually become packaged into new HIV virions. Consequently, after the latency period HIV becomes activated in the host cell. These cells present HIV antigen on their cell surface and alert (CD8+ or CD4+ or B) cells to kill them. As they are killed the infected (CD4+, or CD8+, or B) cells release the HIV virions into the blood stream to infect other (CD4+ or CD8+) cells such as macrophages and dendritic cells. This explains why after latency we see (CD4+, or CD8+) T cells continue to decrease while at the same time viral (DNA, or RNA) levels increase.

Based on your answers to the fill in paragraph, which statement is true?

A. Once active in CD8+ T cells, HIV can now replicate with impunity and infect other cells which explains the increase in HIV RNA after latency.

B. The increase in active HIV after latency accounts for why HIV can remain dormant for years after the initial infection.

C. CD4+ levels stabilize after the latency period and explain why there is little increase in HIV RNA levels.

D. Opportunist infections can occur after HIV latency because there are very few helper T cells to left to activate cytotoxic T cells and B cells to mount an immune response.

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.

MICR 2340 Lecture Notes - Lecture 11: Rna Virus, Lipoprotein, Cytopathic Effect

Document Summary

Get access

Related Documents

MICR 2340 Lecture Notes - Lecture 17: Rna Virus, Dna Virus, Retrovirus

MICR 2340 Study Guide - Final Guide: Western Blot, Rna Virus, Reverse Transcriptase

BIOLOGY 2EE3 Lecture Notes - Lecture 17: Lytic Cycle, Petri Dish, Rna Virus

Related Questions