Unit 8-Microbiology (Notes)

Question 1

Virus Structure

Answer 1

All have: 
   -DNA or RNA (not both like cells)
   -Capsid
Some have:
   -Protein envelope outside capsid
   -Spikes on outside
          -help recognize and attach to cells

Question 2

Virus Shape

Answer 2

1) Rod-Shaped
Ex: tobacco mosaic virus
2) Many-sided
Ex: adenovirus that causes common cold
3) Combination
Ex: bacteriophages that attack bacteria

Question 3

Virus Size

Answer 3

• measured in nanometers
• nanometer
  
  • one-billionth of a meter
    
    • 20-400nm long (really tiny)

Question 4

Virus Specificity

Answer 4

Most attack only one specific cell.

Ex) HIV only attacks helper T-cells

Question 5

Virus Replication

Answer 5

(Reproduction)

• only in a cell
• virus “docks” on site on cell membrane
• enters one or two cycles of replication

Question 6

Origin

Answer 6

1) From inside cells

2) From space

Question 7

Viral Diseases

Answer 7

• smallpox
• hepatitis (inflammation of the liver)
• aids
• common cold
• flu
• mononucleosis
• polio
• chickenpox
• mumps
• cancer triggers? (hpv)
• herpes
• rabies
• some pneumonia (fluid build up in lungs)
• emerging viruses: bird flu, marburg, sars, Ebola

Question 8

Controlling Disease

Answer 8

1) anti-viral drugs
- usually designed to slow replication
- acyclovir, interferon
- AZT and Protease inhibitors
- used to help slow HIV
2) vector control
- disrupt mosquito breeding by not having standing water
3) vaccination
- take a virus and weaken it (attenuate) or chop it up (inactivated)
- inject it into body
- body (immune system) turns on and forms antibodies
- it was not in danger from the vaccine
- next time you are exposed
- antibodies wipe out virus before it gets a “foothold”

Question 9

Smallpox Vaccine

Answer 9

• Chinese 1000 AD
• Africa 1500 AD
• Edward Jenner 1790
• last smallpox case in world was 1977 in Somalia thanks to WHO

Question 10

Problem with Vaccines

Answer 10

• Viruses mutate

- Vaccines no longer work

Question 11

Gene Therapy

Answer 11

• Insert good DNA into a virus
• Virus injects DNA into cell it infects
• Cure for genetic diseases?

Question 12

Antibiotics

Answer 12

DO NOT help a viral illness (flu, colds)

Question 13

Aseptic Technique

Answer 13

1) People
2) Lab
3) Samples

Question 14

Virus Characteristics

Answer 14

• not made of cells
• no cell membrane
• no organelles
• no cytoplasm
• not active outside living cells
• not living