Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

RUSVM Virology Summer 2017 > Effects of Viruses on Host Cells > Flashcards

Effects of Viruses on Host Cells Flashcards

1
Q

Effects of viruses on host cells

A
  1. Cytocidal
  2. Non- cytocidal
  3. Cell transformation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Cytocidal virus effect on host cell

A

= Cell death either via lysis or apoptosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Non- cytocidal virus effect on host cell

A

Persistent infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Cell transformation virus effect on host cell

A

Tumor cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What refers to damage or morphological changes to host cells during virus invasion?

A

Cytopathic Effect or Cytopathogenic Effect (CPE)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Cell fusion (Syncytium or Polykaron formation) results from the fusion of _____(finish the sentence..)____

A

results from the fusion of an infected cell with neighboring infected or uninfected cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

_______ involves fusion of the plasma membranes of four or more cells to produce an enlarged cell with four or more nuclei – they are prone to premature cell death.

A

Cell fusion (Syncytium or Polykaron formation)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

____________ is abnormal structure in a cell nucleus or cytoplasm or both, such as aggregates of proteins, having characteristic staining properties and associated with certain viral infections.

A

Inclusion bodies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

T/F: inclusion bodies help to identify certain viral infection

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Inclusion bodies, in host cell during viral infection, can be all of the following EXCEPT:
A. Accumulation of bacterial components
B. Result from degenerative changes in the cell
C. Crystalline aggregates of virions
D. Intracytoplasmic or Intranuclear (or both)
E. Single or multiple
F. Large or Small
G. Round or Irregular in shape
H. Eosinophilic/ Acidophilic or Basophilic

A

A. Accumulation of bacterial components!!

– should say “Accumulation of VIRAL components!”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

________ stain- recognizes/ has an affinity for acid dyes such as eosin and appear pinkish upon staining.

A

Acidophilic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

_______ stain- recognizes/ has an affinity for basic dyes, such as hematoxylin and appear purplish blue upon staining.

A

Basophilic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

All of the following are general mechanisms of virus - induced cell injury and death EXCEPT:
A. Inhibition of Host- Cell Nucleic Acid Synthesis
B. Inhibition of Host- Cell RNA Transcription (mRNA production and processing)
C. Inhibition of Host- Cell Protein Synthesis
D. Some viruses cause lysosomes to release their hydrolytic enzymes, which then destroy the host cell
E. Interference with Cellular Membrane Function
F. Apoptosis
G. All of the above are general mechanisms of virus - induced cell injury and death

A

G. All of the above are general mechanisms of virus - induced cell injury and death

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

_________ describes the process of programmed cell death, which is essentially a mechanism of cell suicide that the host activates as a last resort to eliminate viral factories before progeny virus production is complete.

A

Apoptosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

______ describes the process when viral replication is complete, host cell is destroyed and new virions are released.

A

Lysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

________ pathways is when: activation of host- cell caspase enzymes mediate death of the cell.Once activated, caspases are responsible for degradation of the cell’s own DNA and proteins.

A

Apoptotic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the two Apoptotic Pathways?

A

1) The Intrinsic (Mitochondrial Pathway)

2) The Extrinsic (Death Receptor Pathway)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

The mitochondria pathway is also known as the ______ pathway

A

Intrinsic (Its an apoptotic pathway)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

The Death receptor pathway is also know as the ________ pathway

A

Extrinsic (Its an apoptotic pathway)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What apoptotic pathway is activated as a result of increased permeability of mitochondrial membranes subsequent to cell injury, such as that associated with viral infection?

A

The Intrinsic (Mitochondrial Pathway)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What apoptotic pathway is activated by engagement of specify cell- membrane receptors, which are members of the TNF receptor family (TNF, Fas, and others)?

A

The Extrinsic (Death Receptor) Pathway

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

T/F: Binding of the cytokine TNF to its cellular receptor can tigger apoptosis in the Intrinsic pathway.

A

FASLE!

Binding of the cytokine TNF to its cellular receptor can tigger apoptosis in the EXTRINSIC pathway.

23
Q

T/F: Cytotoxic T lymphocytes and Natural Killer cells can also initiate apoptosis of virus- infected target cell.

A

True

24
Q

Cytotoxic T lymphocytes and Natural killer cells utilize preformed mediators such as ________ and ________ that directly activate caspases to initiate apoptosis of virus- infected target cell.

A

perforin and granzyme

25
Q

Membrane/ Surface Fusion is only in (Envelope or Non- enveloped) Viruses?

A

Enveloped Viruses!

26
Q

T/F: Viral glycoproteins are retained on the cell surface, and since these are antigenic, the cell can become a target of the immune system of the host (this is during antibody- dependent cell mediated cytotoxicity resulting from surface membrane fusion of enveloped viruses).

A

True

27
Q

What order do the following occur in during Antibody- Dependent Cell Mediated Cytotoxicity?

  1. Cross- linking of Fc receptors signals the NK cell to kill the target cell
  2. Antibody binds antigens on the surface of target cell
  3. Target cell dies by apoptosis
  4. Fc receptors on NK cell recognize bound antibody
A
  1. –> 4. –> 1. –> 3.
28
Q

The changing of a normal cell into a cancer cell is known as _____ ___________.

A

cell transformation

29
Q

T/F: Tumor antigens are antigens that appear on the surface of tumor cells that may provoke an immune response.

A

true

30
Q

What is an example of the expression of tumor antigens?

A

FCOMA- Feline Oncornavirus Membrane- Associated Antigen.

31
Q

_________ is a descriptive term that denotes an abnormal tissue overgrowth that my be either localized or disseminated.

A

Neoplasia

32
Q

________ is the process that leads to the formation of neoplasms (syn. carcinogenesis)

A

Neoplasia

33
Q

The study of neoplasia and neoplasms is called what?

A

Oncology

34
Q

A growth produced by abnormal cell proliferation that remains localized and does not invade adjacent tissue is referred to as ?

A

Benign Neoplasm

35
Q

____________ is locally invasive and may also be spread to other parts of the body.

A

Malignant Neoplasm (cancer)

36
Q

____________ is the spread of cancer cells from the part of the body where it started (the primary site) to other parts of the body.

A

Metastasis

37
Q

Which of the following is NOT true about oncogenic viruses:
A. Viruses that cause or give rise to tumors
B. Viruses that cause cancer
C. Generally, have a RNA genome, or generate a RNA provirus after infection (Retrovirus)
D. All of the above are true about oncogenic viruses

A

C.

– Generally have a DNA genome, or generate a DNA provirus after infection (Retrovirus)

38
Q

____________ Viruses have the viral oncogenes in the viral DNA. These oncogenes cause cancer in host cells, and also may help in the virus replication process.

A

Oncogenic DNA

39
Q

DNA tumor viruses can interact with cells in which two ways?

A
  1. Productive Infection

2. Non- productive Infection

40
Q

Productive Infection

A

When oncogenic DNA viruses infect PERMISSIVE cells, they CAN replicate –> NO CANCER!
- the virus complete its replication cycle resulting in cell lysis.

41
Q

Non- Productive Infection

A

When Oncogenic DNA viruses infect NON- PERMISSIVE cells, they can NOT replicate. It results in CANCER!!

42
Q

T/F: Viral DNA, or a truncated version, integrates into host DNA. In some viruses, the viral DNA persists as an autonomously replicating plasmid (episome) during Non- productive Infection. Virus transforms the cell without completing its replication cycle which leads to cancer.

A

True

43
Q

Oncogenic RNA Viruses- what are the two types of transforming retroviruses?

A

1) Acutely Transforming Retroviruses

2) Slow/ Chronic Transforming Retroviruses

44
Q

_________ transforming retroviruses steal the proto- oncogene from the infected host cell DNA, and then the virus converts the proto- oncogene into the oncogene.

A

Acutely transforming retrovirus

45
Q

The following are all apart of which transforming retrovirus?

  • The virus genome gets inserted into the regulatory (enhancer region) gene of the host cell DNA
  • As a result of this insertion, the regulatory gene cannot function properly
  • There is no control of proto-oncogene of the host DNA
  • The RESULT is EXCESSIVE CELL DIVISION or CANCER.
A

Slow/ Chronic transforming retrovirus

46
Q

What is the cancer causing gene in Acutely transforming retroviruses?

A

V-onc

47
Q

What encodes proteins to function in normal cellular growth and differentiation.

A

Proto- oncogenes

48
Q

_________ _________ genes: play a key role in keeping cell division in check; Encodes proteins that regulates and inhibits uncontrolled growth.

A

Tumor Suppressor

49
Q

What are the two important tumor suppressor genes?

A

1) Rb (Retinoblastoma) protein

2) P53 protein

50
Q

What protein blocks E2F and keeps cell division in check? (Note: E2F facilitates cell division).

A

Rb (Retinoblastoma) protein

51
Q

What protein prevents cells with damaged DNA from entering into cell division; tries to mediate repairing of the damaged host cell DNA?

A

p53 protein

52
Q

If damaged DNA cannot be repaired, ______ mediates apoptosis of the cell with damaged DNA.

A

p53

53
Q

________ are mutated forms of proto- oncogenes or aberrantly expressed proto-oncogenes.

A

Oncogenes

RUSVM Virology Summer 2017 (23 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions