Bacteria

Question 1

what are prokaryotes

Answer 1

An organism whose DNA is not enclosed within a nuclear membrane and lacks membrane-bound organelles

Question 2

what are the 6 subgroups of microbes

Answer 2

bacteria, archaea, algae, fungi, protozoa, viruses

Question 3

what is the envelope function

Answer 3

outer membrane: protection via lipopolysaccharide

cell wall: cell shape & withstand turgor pressure via peptidoglycan

cytoplasmic membrane: regulate the movement of molecules in & out of the cell

Question 4

what is the function of the cytoplasm

Answer 4

90% water, the primary site of chemical activity and no cytoskeleton

Question 5

What is the function of the nucleoid

Answer 5

irregular localization of genetic material (DNA)

Question 6

what is the function of ribosomes

Answer 6

protein synthesis

Question 7

what is the function of storage granules

Answer 7

nutrient reserves (carbon, phosphate)

Question 8

what is the function of pili

Answer 8

surface attachment, bacterial mating conjugation

Question 9

what is the function of the flagellum

Answer 9

motility can move faster

Question 10

what is the function of the capsule

Answer 10

• protection from drying out
• protection from phagocytosis, cell lysis
• protection from oxygen
• adherence virulence

Question 11

what are colonies without capsules

Answer 11

rough colonies

Question 12

what are colonies with capsules

Answer 12

smooth colonies

Question 13

what are colonies with capsules filled with water

Answer 13

mucoid colonies

Question 14

Pili structure

Answer 14

hairlike appendages used for attachment

Mainly common in Gram-negative bacteria

Question 15

Flagella structure

Answer 15

corkscrew-shaped projection(s)
Rotate & propel the cell
Important for chemotaxis

Question 16

what is chemotaxis

Answer 16

movement of bacteria according to a chemical stimulus

• From a low-to-high nutrient/favorable environment
• Away from a toxin or repellent
  also: aero-, photo-, magnetotaxis

Question 17

what are endospores

Answer 17

A resting structure formed inside some bacteria

Question 18

what are endospores resistant to

Answer 18

Extreme heat, dehydration, toxic chemicals, radiation, toughest biological structures to destroy.

Question 19

do endospores tend to be gram-negative or gram-positive

Answer 19

gram-positive

Question 20

what human pathogens are endospores

Answer 20

Bacillus anthracis

clostridium

Question 21

what is archaea

Answer 21

Single-celled organisms lacking nuclear membrane,

Question 22

are archaea extremophiles

Answer 22

yes many are

Question 23

what are thermophiles

Answer 23

live in high-temperature environments

Question 24

what are methanogens

Answer 24

live in anaerobic environments, produce methane

Question 25

what are halophiles

Answer 25

live in extreme salt environments

Question 26

what is taxonomy

Answer 26

science of naming and classifying organisms

Question 27

what is the taxon

Answer 27

domain, kingdom, phylum, class, order, family, genus, species

Question 28

what is a variant

Answer 28

genetic variant or subtype of the same species, altered by mutation or genetic exchange

Question 29

what is a species

Answer 29

related organisms that can freely interbreed and share a common gene pool

Question 30

how do prokaryotes reproduce

Answer 30

asexual reproduction

Question 31

Can bacteria breed with other bacteria

Answer 31

Genetic exchange of genes amongst bacteria is sporadic & can occur between distantly related organisms

Question 32

what are the traditional microbial classifications

Answer 32

morphology, biochemical, physiological, and serological

Question 33

what is a modern classification

Answer 33

comparing genetic material

Question 34

what are spherical bacteria called

Answer 34

coccus

Question 35

what is an oval shape bacteria called

Answer 35

bacillus

Question 36

what do you call bacteria in a line

Answer 36

streptococci or streptobacili

Question 37

what do you call bacteria in a cluster

Answer 37

staphylococci

Question 38

what do you call two spherical bacteria

Answer 38

diplococci

Question 39

Physiological classification

Answer 39

aerobic, anaerobic

temperature range, pH, osmotic strength

Question 40

Biochemical classification

Answer 40

Carbon source
Able to utilise specific carbon sources to support growth
fermentation of glucose, lactose, mannitol, etc.
Enzyme activity

Question 41

what is the indole test

Answer 41

Tests the presence of Tryptophanase

- separate E.coli (positive) from Klebsiella-Enterobacter-Hafnia-Serratia (mostly negative)

Question 42

what is the coagulase test

Answer 42

Tests the ability to clot plasma

- separate S.aureus, from other Staphylococcus spp.

Question 43

what is the catalase test

Answer 43

Ability to decompose hydrogen peroxide to water & O2

- found in most aerobes & facultative anaerobes (main exception is Streptococcus spp.), absent in anaerobes

Question 44

what is serology

Answer 44

study of serum (non-cellular fraction of blood)

the test can detect whether someone has had a bacteria previously

Question 45

what are antisera

Answer 45

sera that inactivate particular bacteria

Question 46

how many layers do gram-negative bacteria have

Answer 46

3 layers:

1. cytoplasmic membrane
2. surrounded by a thin peptidoglycan & periplasm cell wall
3. surrounded by an outer membrane of lipopolysaccharides.

Question 47

how many layers do gram-positive bacteria have

Answer 47

2 layers:

1. cytoplasmic membrane
2. thick cell wall of peptidoglycan