Culture Club

Question 1

What size is a virus?

Answer 1

10-100nm

Question 2

What genome do viruses have?

Answer 2

DNA or RNA

• ss or ds
• linear or circular

Question 3

How metabolically active are viruses?

Answer 3

Metabolically inert

Question 4

What detects PAMPs?

Answer 4

Toll-like receptors

Question 5

What is tropism?

Answer 5

The idea that specific cells, tissues and hosts can support the growth of particular microbes

Question 6

What does HIV normally infect?

Answer 6

Macrophages, but not neurons (cellular tropism)

Question 7

What does the influenza virus infect?

Answer 7

lung tissue but not brain tissue (tissue tropism)

Question 8

How do viruses exit a host cell?

Answer 8

They can bud from the surface

Question 9

Why will some viruses immortalise their host cell?

Answer 9

To use it for their benefit

Question 10

What do some viruses come pre-packaged with?

Answer 10

With enzymes required for their replication, which are virus specific (targets for anti-viral drugs)

Question 11

What is the range for virus host cells>

Answer 11

Can be very specific or broad (multiple cell types/different host species)

Question 12

What does the virus do in the host cell?

Answer 12

Replicate

Question 13

What is the function of a capsule on a bacterium?

Answer 13

• surrounds the cells

- prevents phagocytosis

Question 14

What is the function of a cell wall on a bacterium?

Answer 14

Prevents the cell from bursting
(antibiotic target)
(not always present)

Question 15

What is the function of the plasma membrane on a bacterium?

Answer 15

Site of ATP synthesis

not always present

Question 16

What ribosomes are present on a bacterium?

Answer 16

70s

target for antibiotics

Question 17

What is a plasmid?

Answer 17

Mobile DNA

can carry antibiotic resistant genes

Question 18

What is the function of flagella on a bacterium?

Answer 18

Required for motility

not always present

Question 19

What is the function of pili on a bacterium?

Answer 19

-facilitate DNA transfer between cells
-helps cells move and adhere to surfaces
(not always present)

Question 20

Is the nucleoid always present in a bacterium?

Answer 20

Yes

DNA and RNA polymerases are antibiotic targets

Question 21

What are the 3 groups of bacteria?

Answer 21

• gram positive
• gram negative
• atypicals/acid fast

Question 22

How are bacteria divided?

Answer 22

Based on the structure of their cell wall

Question 23

How are atypicals/acid fast visualised?

Answer 23

Using acid based stains

Question 24

What is present in the membrane of gram negative?

Answer 24

• Lipopolysaccharide
• outer membrane
• peptidoglycan (thin)
• inner (plasma) membrane

Question 25

What is present in the membrane of gram positive?

Answer 25

• (lipo)teichoic acid
• peptidoglycan (thick)
• inner (plasma) membrane

Question 26

What is significant about finding out whether a bacterium is gram negative or positive?

Answer 26

Certain antibiotics can selectively target Gram negative/positive (narrow spectrum antibiotics). Some can target both (broad spectrum)

Question 27

Why can broad spectrum antibiotics be useful?

Answer 27

• if the patient has an unknown infection

- multiple bacteria infecting at once

Question 28

In which bacteria is it easier for water to leave?

Answer 28

Gram negative

Question 29

Which bacteria finds it easier to live on the skin?

Answer 29

Gram positive e.g. streptococcus, staphylococcus

skin is generally dry, and water finds it difficult to leave gram positive

Question 30

Why do gram negative find it difficult to live on the skin?

Answer 30

they will dry out - water finds it easier to leave

Question 31

What is LPS?

Answer 31

Lipopolysaccharide = endotoxin

Question 32

What effect does LPS have on the host?

Answer 32

• induces a strong inflammatory response (can lead to sepsis)
• can induce clotting
• is pyrogenic (leads to fever)

Question 33

What colour does Gram positive stain?

Answer 33

Purple

Question 34

What colour does Gram negative stain?

Answer 34

Pink