Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

a. SL12100: Health and disease > L28B - Introduction To Microbiology And Bacterial Cells > Flashcards

L28B - Introduction To Microbiology And Bacterial Cells Flashcards

1
Q

What are the 2 cell types?

A
  • prokaryotes - bacteria, archea
  • eukaryotes - fungi, protozoa, helminths, slime moulds, algae
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are facts about prokaryotes? (6)

A
  • 1-5mcm
  • haploid
  • asexual reproductions
  • unicellular
  • no true nucleus
  • cell wall
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are facts about eukaryotes? (5)

A
  • > 10mcm
  • diploid
  • sexual reproduction
  • unicellular/multicellular
  • true nucleus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are facts about viruses? (2)

A
  • no cellular structure
  • genetic material surrounded by protein
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are facts about prions?

A
  • no nucleic acid
  • pieces of infectious protein
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are examples of prions? (3)

A
  • bovine
  • spongiform
  • encephalopathy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are facts about bacteria? (5)

A
  • unicellular
  • huge diversity (size, shape, habitat and metabolilsm)
  • majority are harmless/even beneficial
  • some cause disease (pathogenic)
  • some are pharmaceutical contaminants
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the bacterial classification? (3)

A
  • morphology - cell shape, size, motility, spore forming
  • metabolism - use of energy sources/nutrients
  • molecular characteristics - protein, lipid structure, seq of gene encoding 16S RNA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the bacterial shapes in cocci? (4)

A
  • coccus
  • diplococcus
  • chains
  • clusters
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the bacterial shapes in rods?

A
  • single rod
  • paired rod
  • chains
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the different bacterial shapes? (3)

A
  • cocci
  • rods
  • spirals
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the classification of 70S bacterial ribosome?

A
  • 50S subunit (23S rRNA, 5S rRNA + proteins)
  • 30S subunit (16SRNA + proteins)
    = 70S bacterial ribosome
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is important about 16S rRNA gene seq? (4)

A
  • all bacteria have ribosomes = essential gene
  • 16S gene highly conserved
  • hypervariable regions (variation between species)
  • organisms identified by their sequence
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the parts in bacteria cell structure? (6)

A
  • plasma (cytoplasmic) membrane
  • cytoplasm
  • the nucleoid
  • plasmid
  • prokaryotic cell wall
  • ribosomes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the plasma (cytoplasmic) membrane like? (4)

A
  • selective semi-permeable barrier
  • mediates nutrient transport
  • site of secretion and respiration
  • site of environment response regulators
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the cytoplasm? What does it contain? What does it not contain?

A
  • between plasma membrane and nucleoid
  • ribosomes (protein translation, 70S), inclusion bodies (contain important nutrients C, P, N, S)
  • no mitochondria, no true nucleus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the double stranded DNA (dsDNA) like? (4)

A
  • not enclosed by nuclear membrane
  • usually single closed circular chromosome
  • DNA supercoiled
  • 1 copy of each gene
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are plasmids like? (3)

A
  • extrachromosomal, small circular dsDNA
  • replicate independently (multiple copies)
  • encode auxiliary functions
19
Q

What is the prokaryotic cell wall like (3)? What is it composed of?

A
  • protects from the environment
  • rigidity, strength
  • unique to bacteria
  • composed of peptidoglycan cross linked to form mesh
20
Q

What is the peptidoglycan structure? (4)

A
  • glycan backbone made of chain of sugar residues joined by glycosidic bonds
  • every other sugar linked to short peptide
  • peptides crosslink to another on adj glycan backbone
    = strong mesh like structure formed
21
Q

What does the mesh like structure of the peptidoglycan structure allow?

A

Molecules to pass in and out

22
Q

What 2 types of bonds make it strong and rigid?

A
  • glycosidic bonds
  • peptide bonds
23
Q

What are the 2 division of pathogenic baceria due to difference in PG structure?

A
  • gram positive
  • gram negative
24
Q

What is gram positive bacteria like? (3)

A
  • stain purple
  • thick PG layer (20-80nm)< 60-80% cell wal
  • X-linked to form thick mesh
25
Q

What is gram negative bacteria like? (3)

A
  • stain pink
  • thin PG layer (1-3nm), 10-20% cell wall
  • surrounded by outer membrane
26
Q

What do gram positive cell walls contain? (4)

A
  • teichoic acids - acidic polysacchs bonded to PG, transport metal cations
  • lipoteichoic acids - teichoic acids bonded to membrane lipids, release by killed bacteria during infection = inflammatory response
  • plasma membrane
  • PG
27
Q

What do gram negative cell walls contain? (6)

A
  • lipopolysaccharide - stabilises membrane structure
  • porins
  • outer membrane - impermeable to large molecules
  • periplasm - gel-like, contains proteins
  • PG
  • plasma membrane
28
Q

What are lipopolysaccharides (endotoxin) like?

A
  • strong immunogenic
  • extremely toxic to animal cells
  • heat resistant
29
Q

What are the parts of the lipopolysaccharides?

A
  • lipid A - embedded in outer membrane, toxic = endotoxin
  • core polysacch - 10 sugars linked to lipid A
  • O-specific polysacch - surface of outer membrane - immunogenic
30
Q

What are examples of gram positive bacteria? (3)

A
  • staphylococcus // S. aureus
  • streptococcus // S. pneumoniae
  • clostridioides // C. Difficile
31
Q

What are examples of gram negative bacteria? (3)

A
  • escherichia coli, E. Coil
  • pseudomonas // P. Aeuroginosa
  • salmonella // S. enterica
32
Q

What are pathogenic bacteria not classified by gram stain?

A
  • atypicals
  • acid-fast bacilli
  • bacteria lacking peptidoglycan
33
Q

What are acid-fast bacilli like?

A
  • cell wall thick waxy lipidic layer
  • // mycobacteria tuberculosis
34
Q

What are bacteria lacking PG like?

A
  • cause intracellular infections
  • // mycoplasma pneumoniae (atypical pneumonia, problems for tissue culture Chlamydia spp)
35
Q

What are examples of bacterial cell components associated with some bacterial cells? (3)

A
  • (endo)spores
  • capsules and slime layers
  • pili and fimbriae
36
Q

What are bacterial endospores?

A
  • highly resistant dormant structures
  • form inside bacteria in response to adverse conditions (nutrients/oxygen)
37
Q

What are the types of bacterial endospores?

A
  • dormant - survive w/o water and nutrients
  • non reproductive - single ensospore within bacteria, reactivates in response to more favourable conditions
38
Q

What is the structure of bacterial endospores?

A
  • tough outer coat - layers of proteins and PG (resistant UV radiation, desiccation, freezing, high temp and most disinfectants)
  • dehydrated core - cytoplasm and DNA
39
Q

What are capsules and slime layers?

A
  • capsule - firm, rigid hard to remove
  • slime layer - loose layer which is easier to remove
40
Q

What are slime layers and what are their functions (3)?

A

Network of polysachh secreted outside of the PG cell wall
- give protection
- aid attachment
- contribute to virulence (evade body defences)

41
Q

What are fimbria (p-pili)?

A

Aid attachement to surfaces

42
Q

What are F-pili?

A

Used in bacterial conjugation (transfer of genetic material between cells)

43
Q

What are P-pili and F-pili like? (2)

A
  • morphologically and chemically similar
  • hair like structures composed of protein subunits

a. SL12100: Health and disease (38 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions