Microorganisms

Question 1

What is a Protozoa?

Answer 1

Single celled organisms without a cell wall (mostly) and some move around freely

Question 2

What is an example of a Protozoa?

Answer 2

Plasmodium spp.

Transmitted by mosquito (vector) and infects RBC in humans

Causes malaria

Question 3

What is a microorganism?

Answer 3

Microscopic organism

Mostly unicellular

Eg bacteria, fungi, Protozoa, algae abs viruses

Question 4

What are fungi?

Answer 4

Microorganisms that are generally non motile with cell walls

Question 5

What are fungus cell walls mostly comprised of?

Answer 5

Chitin

Question 6

What are moulds?

Answer 6

Multicellular

Composed of cells arranged in branching filaments- hyphae

Question 7

What is yeast?

Answer 7

Unicellular microorganisms

Question 8

What is the function of spores?

Answer 8

Produced by fungi

Utilised by fungi to reproduce

Question 9

What is immunosuppression?

Answer 9

When the host has a weakened immune system

Question 10

What does bacilli mean?

Answer 10

Rod shaped bacteria

Question 11

What are cocci?

Answer 11

Sphere shaped bacteria

Question 12

What does spirochetes mean?

Answer 12

Spiral shaped bacteria

Question 13

What does diplo mean?

Answer 13

Two bacteria are joined together

Question 14

What does strepto mean?

Answer 14

Chains of bacteria

Question 15

What does staphylo mean?

Answer 15

‘Grape-like’ clusters of bacteria

Question 16

What does gram positive and gram negative relate to?

Answer 16

Whether bacteria retain a stain when the grab mmm stain technique is applied

Question 17

What is Gram positive bacteria?

Answer 17

Retain the stain

Result of high levels of peptidoglycan in their cell walls

Question 18

What is gram negative bacteria?

Answer 18

Do not retain the stain

Smaller concentrations of peptidoglycan in their cell wall

Question 19

What is binary fission?

Answer 19

How bacteria reproduce

Divide into 2 once they have doubled their size and replicated their chromosomes

Asexual process

Question 20

What are the major components of a bacteria cell?

Answer 20

1) has a cell wall and usually capsule/slime layer outside of this
2) cell (plasma) membrane
3) do not have membrane bound organelles
4) have ribosomes
5) pili present to enable attachment to surfaces
6) singular circular molecule of DNA (nucleoid) found in cell cytoplasm

Question 21

What is vegetative bacteria?

Answer 21

Growth and reproduction form of the bacteria

Question 22

What happens to bacteria when conditions become unfavourable?

Answer 22

Resistant to desiccation, extreme temp. and many chemicals

Some produce spores- survive extreme environmental conditions

Spores remain viable- only germinate once conditions become favourable

Eg clostridium difficile

Question 23

What she’s commensal organism mean?

Answer 23

Bacteria benefit from host environment while host is neither harmed nor benefited

Question 24

What does normal flora mean?

Answer 24

Populations of organisms that live in various parts of the body but don’t cause disease

Question 25

What does pathogen mean?

Answer 25

Parasite that can cause disease

Question 26

What does mutualism mean?

Answer 26

Both microorganism and host benefit from living together

Question 27

What are the 5 characteristics of viruses?

Answer 27

1) generally smaller than bacteria
2) contain small amounts of nucleic acid (DNA or RNA)
3) genome surrounded by protein coat (capsid) which protects it
4) viruses may be enveloped or non-enveloped
5) many shapes- helix, spiral, cuboid and icosihedral

Question 28

What are prions?

Answer 28

Infectious proteins

They are extremely hardy and resistant to disinfection,m, heat etc

Antivirals/antibiotics have no effect

Infectious form of protein causes diseases eg new variant Creutzfeldt Jacob disease (CJD)