Session 2 - Microbes

Question 1

what are prions

Answer 1

proteins which can make copies of themselves and spread from person to person

Question 2

what must be used to see viruses

Answer 2

electron microscope

Question 3

how does the genetic material differ in viruses

Answer 3

• single or double stranded

- RNA or DNA

Question 4

what does it mean when viruses have an envelope

Answer 4

they have a lipid bilayer on the outside which makes it less easy to disrupt the virus

Question 5

why are there spikes on the outside of the virus

Answer 5

to allow it to attach to specific cell surfaces as they must bind to a cell before they can enter it

Question 6

what is a bacteriophage

Answer 6

a virus that infects and replicates within a bacteria

Question 7

what is the capsule of a bacteria made up of

Answer 7

polysaccharides

Question 8

what Is the cell wall of a bacteria made from

Answer 8

peptidoglycan

Question 9

true or false: the bacterial capsule is a virulence factor

Answer 9

true, as it enhances the bacteria’s ability to cause disease

Question 10

What are the 3 bacterial shapes

Answer 10

1. coccus (round)
2. Spirillus (spiral)
3. Bacillus (rod)

Question 11

what are the 2 arrangements of bacteria

Answer 11

1. clusters

2. chains

Question 12

what are aerobes

Answer 12

microbes that can survive in the presence of oxygen

Question 13

what are obligate aerobes

Answer 13

microbes that require oxygen for survival

Question 14

what are anaerobes

Answer 14

microbes that survive in the absence of oxygen

Question 15

what are obligate anaerobes

Answer 15

microbes that require an oxygen free environment for survival

Question 16

what is used to name bacteria, fungi and parasites

Answer 16

Linnaean taxonomy

Question 17

what are organisms named using Linnaean taxonomy

Answer 17

Genus + species

Question 18

give 3 examples of virulence factors

Answer 18

1. polysaccharide caspule
2. pili (structure to allow attachment
3. iron sequestration

Question 19

give an example of a substance which causes iron sequestration

Answer 19

siderophores

Question 20

what are exotoxins

Answer 20

toxic substances secreted by the bacteria deliberately to cause damage to the host and allow bacterial replication

Question 21

what are endotoxins

Answer 21

substances such as lipopolysaccharides that are released when the bacteria breaks down

Question 22

how does the ribosome size differ in prokaryotes and eukaryotes

Answer 22

70S in prokaryotes and 80S eukaryotes

Question 23

true or false: prokaryotes have membrane bound organelles

Answer 23

false

Question 24

true or false: fungi and parasites are prokaryotes

Answer 24

false

Question 25

what is the genetic information like in prokaryotes

Answer 25

• single stranded (usually), circular

- plasmids (extra, small, circular pieces of DNA)

Question 26

what are single celled fungi called

Answer 26

yeast

Question 27

what are multicellular fungi called

Answer 27

Molds

Question 28

what are single celled parasites called

Answer 28

Protozoa

Question 29

what are multi-cellular parasites called

Answer 29

Helminths

Question 30

what allows bacteria to have a gram negative stain

Answer 30

the bacteria have a lipopolysaccharide capsule and a thinner peptidoglycan layer

Question 31

what are gram stains

Answer 31

technique used to differentiate 2 groups of bacteria based on their cell wall constitutes

Question 32

how are gram stains carried out

Answer 32

• flood slide with the fixed specimen with crystal violet solution
• rinse slide then flood with iodine
• rinse off excess iodine with acetone
• wash slide with water (only gram positive will be seen at this point)
• apply safranin counterstain to see gram negative
• wash in water

Question 33

what colour is a positive gram stain

Answer 33

purple

Question 34

what colour is a negative gram stain

Answer 34

red

Question 35

true or false: gram negative bacteria have a larger peptidoglycan layer

Answer 35

false

Question 36

What does Helicobacter pylon cause

Answer 36

Stomach ulcers and stomach cancer

Question 37

What does human papillomavirus cause

Answer 37

Warts and cervical cancer

Question 38

True or false: staphylococcus is a common bacteria found on the skin

Answer 38

True