Week 4

Question 1

What is Pyknosis?

Answer 1

A degenerative condition of a cell nucleus marked byte clumping of the chromosomes, hyperchromatism, and shrinking of the nucleus.

Question 2

What are inclusion bodies?

Answer 2

Abnormal structure in a cell nucleus and/or cytoplasm that have characteristic staining properties and are associated with certain viral infections.

Question 3

What are Negri bodies?

Answer 3

Consist of ribonuclear proteins produced by the rabies virus

Question 4

What is the Owl’s Eye for?

Answer 4

Seen in herpes virus infection

Question 5

What are crystalline aggregates of virons?

Answer 5

Usually found in adenovirus infections

Question 6

What are the 3 effects of viruses on host cells?

Answer 6

Cytocidal, Non-cytocidal, AND Cell Transformation

Question 7

Cytocidal leads to…

Answer 7

Cell death by Lysis or Apoptosis

Question 8

Non-Cytocidal leads to..

Answer 8

Persistent Infection

Question 9

Cell Transformation leads to…

Answer 9

Tumor cells

Question 10

What is Apoptosis?

Answer 10

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

Question 11

What is Lysis?

Answer 11

Where a host cell is destroyed and new virions are released

Question 12

There are 2 different ways of Apoptosis. There is the intrinsic mitochondrial pathway and there is the extrinsic death receptor pathway. T or F>

Answer 12

TRUE

Question 13

What activates the mitochondrial pathway?

Answer 13

Increased permeability of mitochondrial membranes due to cell injury

Question 14

What activates the death receptor pathway?

Answer 14

Engagement of specific cell membrane receptors. Binding of cytokine TNF to its cellular receptor triggers apoptosis

Question 15

Cytotoxic T lymphocytes and natural killer cells can trigger apoptosis by utilizing what mediators?

Answer 15

Performing AND Granzyme

Question 16

Neoplasia is..

Answer 16

Abnormal tissue overgrowth, leads to the formation of neoplasms

Question 17

Proto-oncogenes do what?

Answer 17

Encode proteins that function in normal cellular growth and differentiation

Question 18

Tumor Suppressor genes do what?

Answer 18

Keep cell division in check. Encodes proteins that regulate and inhibit uncontrolled growth.

Question 19

How do Proto-oncogenes become oncogenes?

Answer 19

Viruses, UV rays, or Chemicals

Question 20

What was one of the first tumor-suppressor genes discovered?

Answer 20

Rb gene, Retinoblastoma protein

Question 21

What does Rb do?

Answer 21

Un-phosohorylated Rb will bind to the transcription factor E2F and prevent its activity—- this will not allow cell division to proceed from G1 to S phase

Question 22

Why is phosphorylated Rb not good?

Answer 22

Bc it cannot bind with E2F, which releases E2F from its inhibition and the cell cycle progresses.

Question 23

What does P53 do?

Answer 23

Activates the DNA repair system and stops the cell cycle at the G1 checkpoint (before DNA replication)

Question 24

What does an Enhancer gene do?

Answer 24

A transcription regulatory sequence located some distance from the promoter; it increases the rate of initiation of transcription

Question 25

What does a Promoter Gene do?

Answer 25

DN sequence at which DNA-deep RNA polymerase binds to initiate transcription