Brainscape's Knowledge GenomeTM

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


See full index

Year One: Pesky Things > Bacterial Morphology and Growth > Flashcards

Bacterial Morphology and Growth Flashcards

1
Q

Summarise the methods for clarifying bacteria

A
  • Size
  • Gross structure
  • Cell wall structure
  • Differential stains
  • Morphology
  • Growth requirement
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the range of bacteria size?

A

0.3μm - 3μm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Summarise the structural components of bacteria

A 
•	Haploid (single chromosome) DNA (circular)
•	DNA in nucleoid region : NOT bound in a nucleus, 
•	Ribosomes in cytoplasm
•	Peptidoglycan membrane
•	No mitochondria
•	No membrane bound organelles
•	+/-  Capsule
•	+/-  Pilli / Flagella
\+/-  Spore to sleep,
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Summarise the steps in staining bacteria

A
  1. Fixed
  2. crystal violet
  3. iodine
  4. alcohol
  5. carbol Fuschin or Safranin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what does the alcohol do to gram negative bacteria

A

the alcohol step damages the outer membrane and allows the BLUE/PURPLE crystal violet dye out.
• - The second safranin/carbol fuschin dye then stains the cell wall RED/PINK

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the colours for gram positive and negative bacteria stains?

A
  • o Gram Positive ▪ Blue/Purple

* o Gram Negative ▪ Red/Pink

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How are acid fast stained and what do the stains indicate?

A

Ziehl-Neelson stain

Use acid not alcohol to wash off stain.

RED or FLUORESCENT if Acid Fast
- NO STAIN if Non-Acid Fast

o Non-Acid Fast = they do not retain the carbol fuschin/auramine stain on the cell surface when washed with acid.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Name 4 gram +ve cocci

A
  • Gram positive cocci in pairs (diplococci) eg. Streptococcus pneumoniae (pneumonia)
  • Gram positive cocci (in chains)- Streptococcus pyogenes (pharyngitis)
  • Gram positive cocci in clusters Staphylococcus aureus (toxic shock syndrome)
  • Gram positive rods (bacillus)- Corynebacterium diphtheriae (diphtheria)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Name 4 gram+ve rods with spores

A
  • Clostridium tetani (tetanus)
  • Clostridium perfringens (gangrene)
  • Clostridium difficile (pseudomembranous colitis)
  • Bacillus anthrax (anthrax)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Gram negative rods (bacilli)…

A 
•	Escherichia coli (colitis)
Salmonella typhi (typhoid fever)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Gram -ve Spiral (helical) shaped

A
  • Treponema pallidum (syphilis)
  • Helicobacter pylori (stomach ulcers)
  • Vibrio cholerae (cholera)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Name a bacteria with no cell wall. What does it have instead?

A

Mycoplasma pneumoniae (atypical pneumonia)

• Have only lipoprotein outer coat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Factors affecting growth(8)

A
  • Division rate
  • Lag phase time
  • Oxygen availability
  • Carbon availability
  • Temperature
  • pH
  • Inhibitors
  • Growth Factors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Name a bacteria that are rapid growers

A

Vibrio cholerae

• Division every 20-40 minutes = 1,073,741,824 bacteria from 1 starting cell overnight

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Name a slow grower

A
  • Treponema pallidum (syphilis)

* Division every 30 hours

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Name a dormant bacteria

A
  • Mycobacterium tuberculosis

* Division every 18 hours (min) - 80 years

17
Q

Describe Obligate Aerobes

A
  • Require SOME oxygen to make ATP (energy/growth)
  • Most tolerate O2 ( Air = 21% O2 : 0.04% CO2 ) eg Pseudomonas aeruginosa
  • Some (Microaerophiles) only tolerate 5% O2 eg Helicobacter pylori
  • Some (Capnophiles) require CO2 higher than in air (5-10%) eg. Neisseria gonorrhoeae
18
Q

Describe facultative anaerobes

A

• Use oxygen or fermention or anaerobic respiration eg. E.coli

19
Q

Aerotolerant Anaerobes…

A

• Cannot use oxygen but can tolerate it eg. Clostridium botulinum (botulism)

20
Q

Obligate Anaerobes

A

• Oxygen is toxic eg. Clostridium tetani (tetanus). Overcomes by spores tso it doesn’t need to grow

21
Q

Summarise some temperatures types of bacteria and give examples

A
  • Psychrophiles (-20ºC to 20ºC) Campylobacter jejuni (food poisoning)
  • Mesophiles (2ºC to 45ºC) Most animal pathogens
  • Thermophiles (42ºC to 80ºC) Bacillus stearothermophilus (used for sterilisation strips)
  • Extreme (hyper) thermophiles (60ºC to 250ºC) Thermus aquaticus (source of Taq for PCR)
22
Q

What are bacteria that work in acidic, neutral and alkaline called. Give examples

A

Acidophile- Helicobacter plyori

Neutral- most human pathogens

Alkaliphile Bacillus cereus- food poisoning

23
Q

• Bacteria with the Lac gene can…

A

• Bacteria with the Lac gene can ferment Lactose

24
Q

Why systemic classification?

A
  1. Shows how much is present ( + culture : shows viability)
    Important from normally sterile samples (blood, CSF)
    Quantification can give a measure of risk
  2. Pathogen confirmation
    Not all bacteria are pathogens (Commensals)
    Commensals in one host can cause disease in another
  3. Indicates treatment options
    Clinico-pathological manifestations are often species specific
    Antibiotic selectivity for bacterial targets
  4. Speciation enables epidemiological study

Year One: Pesky Things (20 decks)

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