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41 Cards in this Set

  • Front
  • Back
1. Capsules
- Loose polymer of _____
- Exact chemical structure varies between species
- Highly viscous → colonies appear “mucoid” (slimy, wet)
- Found in gram pos, neg (& most pathogens)
- Require special stains to be seen (eg. Negative stain)
polysaccharide + protein
____ is a population of cells on a surface held together by capsule
Biofilm formation involves cell to cell communication (known as “_____”)
Quorum sensing
Formation of Biofilm: Free-living cells attach and secrete a chemical signal called _____
homoserine lactone
Flagella have a complex, 3 - part structure:
• ___ → “rings” buried in cell envelope
• ___ + ___ → appendage extending outward from cell
⇒ Complete structure able to rotate (propeller - like) and move cell
Basal body

Hook + Filament
___ are required for attachment of bacteria to other cells
Pili aka Fimbriae
Two Types of Pili: ___ pili - attachment of bacteria to other bacteria; ____ pili - attachment of bacteria to eucaryotic cells (used by
many pathogens to attach to host tissues)
Sex, Common pili
Spores are mostly gram ___
Two steps of Spore life cyle:
Sporulation, Germination
In Sporulation: Multi-layered “wall” (___ + ___)
forms around bacterial DNA
PG + protein
____ is the orderly increase in cell components, followed by DNA replication and cell division to create two identical “daughter” cells
Binary Fission
G= Generation Time = ___ time

in min or hr/ gen
Growth rate = number of __ per ___
generations per hour
In Growth Stages of Populations the time during which cells are most sensitive to antibiotics,
external stresses, etc. is ___
Exponential/ Log Phase
In Growth Stages of Populations, During death phase we See decrease in viable count, but ___ is unaffected
Most bacteria (and all pathogens) are “____”
→ aka use organic material (sugars, fats, proteins) as a
source of carbon and to generate energy
pH level: Some species tolerate extremes (generally not human pathogens):
- ___ → pH 1.0 - 5.0
- ___ → pH > 9.0

Osmotolerant bacteria (eg.____ ) - up to 10% NaCl
- often present on skin
____- (“salt-loving”) - up to 30% NaCl
- mostly Archaebacteria in extremely salty environments
- increase intracellular potassium to balance external salt
Classification of bacteria based on Temperature requirements:
-___ opt. ≈ 10°C
-___ opt. ≈ 37°C
-___ opt. ≈ 70°C
-___ opt. > 80°C
Classification of bacteria based on O2 requirements:
-____ have absolute requirement for atmospheric oxygen
-____killed by O2 (grow only if O2-free) (eg. intestinal bacteria)
-___ grow best if O2 present, but do not require it (eg. E. coli)
-___don’t use O2 for metabolism, but survive in its presence
-___ grow best at low [O2]
Obligate Aerobes
Obligate Anaerobes
Facultative Anaerobes
Free Radicals + Hydrogen => ___ + ____ (catalyzed by ___)

Hydrogen Peroxide => ___ and oxygen (catalyzed by ___)
Hydrogen Peroxide and Oxygen (catalyzed by superoxide
Water and oxygen (catalyzed by catalase)
Anaerobic (“Gas-Pak”) Jar:
- chemical rx. generates H2 + CO2
- H2 reacts with __ to generate water
- O2 removed & replaced by __ and __
O2, CO2 & H2O
Bismuth Sulfite Agar
- sulfite inhibits growth of gram ___ and most gram ___
- will not inhibit ____ (intestinal pathogen)→ use to select for ___ from a specimen containing
a mixed bacterial population (eg. fecal sample)
Pos., Neg.

Salmonella typhi
S. typhi
Blood Agar differentiates “___”(zone of clearing because ____) vs. “____” bacteria(no toxin, no zone of clearing)
hemolytic, hemolysin
vs non-hemolytic
MacConkey Agar
- Contains ___ & ___ ⇒ inhibits growth of gram ___ but not gram ___ (selective)
- Contains ___ & pH indicator
⇒ if ___ metabolized → acidic wastes → pH drops
⇒ if ___ not metabolized → no pH drop (differential)
bile salts & crystal violet
pos. but not neg.

lactose, lactose, lactose
Mannitol Salt Agar
-salt inhibits everything except osmotolerant species
(eg. ___ )-selective
-differentiated on basis of ability to metabolize mannitol and produce acidic wastes:
-__ metabolizes mannitol
-__ non metabolizer
Staphylococcus species

S. aureus metabolizes
S. epidermidis doesn't
sum total of genetic information in organism
outward appearance of organism, as directed by genotype
___discovers “transformation”using smooth and rough capsule experiment (Strep pneumoniae)
“Smooth” - has capsule → lethal
“Rough” - no capsule → not lethal
___ - creates supercoils
___ - removes supercoils
DNA gyrase

Topoisomerase I
Chromosome replication in bacteria:Begins at _____ point(s) on chromosome vs. ___ point(s) on euc. chromo.

Proceeds bi-directionally
from origin

Euc. export mRNA from nucleus → cytoplasm prior to translation vs. Proc. - No export - mRNA translated as soon as it is produced
(“coupling” of transcription & translation)
Euc. genes have non-coding “____” → transcribed into mRNA, but removed before translation (Proc. genes do not have _____)
introns, introns
___ is a physical change in DNA sequence (genotype)
Gain of function mutants = “____ Selection” method (create an environment where mutant can grow)

Loss of function mutants = “____ Selection” method (create an environment where mutant can't grow)
Indirect=>replica plating

____ is unable to
synthesize proline and only grow if proline supplied in media
proline auxotroph
Identification of chemical carcinogens using the The __ Test (a “reversion” mutation)
____ is joining of DNA from two separate sources
Transduction→ DNA transfer via _____
Three Mechanisms of Gene Transfer:
___ is an enzyme used by phage to escape host bacteria by degrading peptidoglycan, resulting in osmotic lysis of cells
-Less effective against gram ____ (can’t penetrate OM)