Viruses

Question 1

Structure of a Virus

Answer 1

• Protein Coat (some have a lipid envelope)

- Genetic Material (DNA or RNA)

Question 2

Lytic Cycle Steps (Cell lysis)

Answer 2

1. Attachment to the membrane
2. Injection of DNA into the cell and degradation of Host DNA. - Viruses takeover and turn cells into a virus factory.
3. Cell Synthesizes viral genome and proteins
4. Assembly of new viruses
5. Cell Lysis and release of viruses

Question 3

What do viruses target?

Answer 3

Particular cells or cell types

Question 4

Lysogenic Cycle

Answer 4

• DNA doesn’t take over cell, but stays dormant.
• Cell splits, now two cells have virus DNA and so on
• Eventually, the DNA is triggered and the cell enters the 3rd step of the lytic cycle.

Question 5

Life cycle of viruses with lipid envelope.

Answer 5

• Lipid coat allows them to enter the cell
• Lipid envelope fuses with cell membrane, DNA infection, new viruses sent out via exocytosis.
• -some viruses are harmful and some less so

Question 6

Human Immunodeficiency Virus (HIV)

Answer 6

• transmitted through bodily fluid
• -can’t survive outside of bodily fluid
• targets CD4 cells (Helper T cells) of the immune system which helps to stimulate every other aspect of the immune system.

Question 7

Enterovirus D68

Answer 7

• Enters through GI tract
• Found in respiratory secretions
• Cold/flu like symptoms

Question 8

Ebola Virus

Answer 8

• Initially from wild animals, then human to human

- Targets some immune cells, cells lining the blood vessels, and liver cells.

Question 9

Problems with viruses

Answer 9

• Not cells
• -Cells provide targets for medications (membrane protein etc.) ,(which viruses don’t have).
• Constantly Mutating
• -medication works on one strain, but not another.