Exam 2 Virus and Prions PT 2

Question 1

Prions

Answer 1

proteins found in our brain that misfold

Question 2

What occurs during the five major steps of viral replication

Answer 2

1.) Virus attaches to cell
2.) Virus Enters cell
3.) Virus synthesis. Gathers its parts to make more
4.) Viruses assembles the parts and puts them together
5.) Virus releases itself from the cell

Question 3

What are the two mechanisms of bacteriophage replication

Answer 3

Lytic Replication(all phage can do this)
Lysogenic Replication (only some phage can do this)

Question 4

Lytic Replication

Answer 4

1.) Attachment
2.) Entry
3.) Bacterial Chromosome is broken up/destroyed
4.) Synthesis new phage proteins and genomes
5.) Assemble
6.) Release

Question 5

Lysogenic Replication

Answer 5

1.) Attachment
2.) Entry
3.) Provirus binds with chromosome
4.) Replication of chromosome and virus ->Multiple times
5.) Induction (Lysogenic cycle is converted into the lytic cycle)
6.)Synthesis new phage proteins and genomes
5.) Assemble
6.) Release

Question 6

Describe Major Mechanisms of virus entry

Answer 6

Direct Penetration

Membrane Fusion

Endocytosis

Question 7

Assembly of DNA

Answer 7

• Looks like human DNA
• DNA assembles in the Nucleus
  Genome is replicated by cell DNA polymerse
  Proteins host RNA Polymerse transcribes DNA to RNA
  Ribosome translate RNA to Proteins
• Both happen in the cytoplasm

Question 8

Synthesis of DNA

Answer 8

1.) Attachment
2.) Entry
3.) Synthesis
- viral genomes with cell DNA polymerase
- viral proteins with ribosomes
4.) Assembly
5.) Release

Question 9

Assembly of RNA

Answer 9

-Genome does not look like human DNA
- RNA assembles in the cytoplasm
-Viruses need a special viral enzyme
Genome is replicated by viral RNA polymerase
-Happens in the cytoplasm
Proteins ribosomes translate RNA to protein
-Happens in the cytoplasm

Question 10

Synthesis of RNA

Answer 10

1.) Attachment
2.) entry
3.) Synthesis new viral RNA to new capsid protein
4.) Assemble
5.) Release

Question 11

How are non-envelope virus’s releases from a cell

Answer 11

Lysis- Plasma Membrane ruptures
Exocytosis- vesicle with virus inside fuses with plasma membrane

Question 12

How are enveloped virus’s releases from a cell

Answer 12

Budding- cell pushes through plasma membrane

Question 13

Diseases Prions Cause

Answer 13

• Spongiform encephalopathies
• Scrapie
• Mad cow Disease
• Kuru
• Creutxfeldt-Jakob Disease

Question 14

How are prions transmitted and replicated

Answer 14

Transmitted by ingestion, transplantation, and contact with mucous membrane

Replicated by converting normal proteins to misfolded form

Question 15

How are prions destroyed

Answer 15

Destroyed by Incineration and or autoclaving in concentrated sodium hydroxide

Question 16

How can proteins, that cannot replicates itself, be a transmissible pathogen and cause disease?

Answer 16

-Converts normal protein into misfolded form
- prions build up causing neuronal death
-Indivisual dies

Question 17

Direct Penetration

Answer 17

Non-enveloped viruses do this

Capsid stays out, genome goes

Question 18

Membrane Fusion

Answer 18

Enveloped virus can do this

Membrane comes together, Releases Capsid

Question 19

Endocytosis

Answer 19

triggered

Non-enveloped virus can do this