1.1 Flashcards

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1
Q

Microorganisms and the human body (5)

A
bacteria
viruses
fungi
protozoa
helminths (worms)
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2
Q

microbiome (4)

A

bacteria
viruses
fungi
protozoa

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3
Q

Parasitic organisms

A

Symbionts that harm or live at the expense of their host

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4
Q

Commensal organisms

A

Normal microbiota - microbes frequently found on or within

the bodies of healthy persons

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5
Q

Infection

A

–growth and multiplication of parasite on or within host

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6
Q

Infectious disease

A

–disease resulting from infection

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7
Q

Pathogen

A

–any parasitic organism that causes infectious disease

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8
Q

primary (frank) pathogen –

A

causes disease by direct

interaction with host

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9
Q

opportunistic pathogen –

A

causes disease only under certain

circumstances

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10
Q

Pathogenicity

A

–ability of parasite to cause disease

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11
Q

Virulence factor

A
  • any component of a pathogenic microbe that is required for

or that potentiates its ability to cause disease

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12
Q

steps in infectious disease (6)

A
encounter 
entry
spread
multiplication
damage
outcome
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13
Q

Encounter (3)

A

Exogenous
Endogenous
Congenital

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14
Q
  1. Entry (2)
A

ingress

penetration

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15
Q

Ingress:

A

inhalation, ingestion

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16
Q

Penetration:

A

microbes pass through epithelia directly (via
attachment and internalization), insect bites, cuts
and wounds, organ transplants and blood
transfusions

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17
Q

Spread (3)

A

lateral propagation versus dissemination
anatomical factors
active participation by microbes

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18
Q

Multiplication (2)

A
environmental factors (e.g. temperature)
subversion of host defenses
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19
Q

Mucormycosis (fungal infection) in

rhinocerebral form, almost always with (2)

A

hyperglycemia and metabolic acidosis

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20
Q

Damage (2)

A

direct damage

immune response

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21
Q

Outcome (3)

A

microbe wins, host wins, or they learn to coexist

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22
Q

Normal microbiota-

A

microbes frequently found on or within
the bodies of healthy persons
commensal organisms

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23
Q

Colonization by bacteria occurs rapidly after

A

birth

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24
Q

— of bacterial species are part of the normal flora.

A

Thousands

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25
Q

The Human Microbiome

A

the collection of all the microorganisms living
in association with the human body
eukaryotes, archaea, bacteria and viruses

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26
Q

Bacteria in an average human body number — times more than human cells

A

ten

contain a total of about 1000 more genes than are present in the human genome because of their small size bacteria make up only about 1-3% of our body mass
2 to 6 pounds of bacteria in a 200-pound adult

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27
Q

Bacteria in the microbiome of a healthy individual are essential for maintaining —

A

health

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28
Q

Bacteria in the microbiome of a healthy individual are essential for maintaining health (6)

A

produce some vitamins that we do not have the genes to make
break down our food to extract nutrients we need to survive
teach our immune systems how to recognize dangerous invaders
produce helpful anti-inflammatory compounds that fight off other disease-causing microbes
occupy space to crowd out disease-causing microbes
detoxification of carcinogens but sometimes are the source of carcinogen production

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29
Q

Changes in the composition of our microbiomes correlate with

A

numerous disease states

source of infection
manipulation of these communities could be used to treat disease

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30
Q

Locations in body with largest amounts of bacteria (5)

A
skin (especially moist areas)
respiratory tract (nose and oropharynx)
digestive tract (mouth and large intestine)
urinary tract (anterior parts of urethra)
genital system (vagina)
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31
Q

Other body locations have small numbers of bacteria.

A

Remainder of respiratory and digestive tracts

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32
Q

Some body locations are sterile. (4)

A

blood, cerebrospinal fluid, synovial fluid, deep tissues

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33
Q

Transient vs. resident organisms

A
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34
Q

Pathogenicity/virulence also depend on the

A

host

Definition of pathogen not so certain

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35
Q

periodontitis -

A

overgrowth of particular bacteria in gingival

crevices

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36
Q

pneumonia -

A

defenses lowered and microaspirations of

pneumococci

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37
Q

catheter-associated infections -

A

staphylococci

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38
Q

Oral flora includes (4)

A

bacteria (and archeae)
fungi
protozoa (eukaryotes)
viruses

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39
Q

~— different species of bacteria are estimated to

be present in the oral cavity

A

700

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40
Q

Oral habitats (5)

A
buccal mucosa
dorsum of tongue
tooth surfaces
crevicular epithelium
dental appliances
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41
Q

Issues for microbial cells (3)

A

Nutritional fluxes
Maintaining occupancy
Resistance to damage

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42
Q

anatomical features that create areas that are

difficult to clean (4)

A
  • shape and topography of teeth
    e. g. fissures
  • malalignment of teeth
  • poor quality of restorations (e.g. fillings and bridges)
  • non-keratinized sulcular epithelium
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43
Q

saliva fxns (7)

A

mixture of inorganic ions
organic constituents
salivary pellicle
source of food
promotes aggregation of bacteria, facilitating their clearance from mouth
inhibits growth of microbes by non-specific defense factors
maintains pH

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44
Q
saliva 
organic constituents (2)
A

proteins

glycoproteins (e.g. mucin)

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45
Q

salivary pellicle

A

promotes adhesion of bacteria on tooth surfaces

organic components form a coating on tooth surfaces

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46
Q

gingival crevicular fluid (5)

A
flushing microbes out of crevice
source of nutrients for microbes
maintains pH
specific and non-specific defense factors
phagocytosis
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47
Q

phagocytosis

— main phagocyte

A

neutrophils

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48
Q

microbial factors (4)

A

competition for adhesion receptors
toxin production
metabolic end products
coaggregation

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49
Q

metabolic end products

A

negative vs. positive effects

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50
Q

local pH

will vary with diet as a result of

A

bacterial metabolism

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51
Q

redox potential

A

a measure of oxygen levels in locality

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52
Q

Factors modulating oral microbial growth (9)

A
anatomical features that create areas that are difficult to clean
saliva 
GCF
microbial factors 
local pH
redox potential 
antimicrobial therapy 
diet 
iatrogenic factors
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53
Q

iatrogenic factors

A

dental scaling

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54
Q

— are an absolute requirement for

all living organisms

A

membranes

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55
Q

plasma membrane encompasses the —

A

cytoplasm

56
Q

some prokaryotes also have

A

internal
membrane systems

most DO NOT

57
Q

The Plasma Membrane contains (2)

A

lipids and proteins

– lipids usually form a bilayer
– proteins are embedded in or associated with lipids

58
Q

PM characteristics (4)

A

highly organized, asymmetric, flexible, and

dynamic

59
Q
The asymmetry of most
membrane lipids 
polar ends (2)
nonpolar ends (2)
A
• polar ends
– interact with water
– hydrophilic
• nonpolar ends
– insoluble in water
– hydrophobic
60
Q

peripheral proteins

A

– loosely associated with the membrane and

easily removed

61
Q

integral proteins

A

– embedded within the membrane and not easily

removed

62
Q

Functions of the plasma

membrane (4)

A

• separation of cell from its environment
• selectively permeable barrier
• location of crucial metabolic processes
• detection of and response to chemicals in
surroundings with the aid of special
receptor molecules in the membrane

63
Q

selectively permeable barrier (2)

A

– some molecules are allowed to pass into or out
of the cell
– transport systems aid in movement of
molecules

64
Q

Inclusion Bodies

A

• granules of organic or inorganic material

that are stockpiled by the cell for future use

65
Q

Inclusion Bodies

some are enclosed by a

A

single-layered
membrane
– membranes vary in composition
– some made of proteins; others contain lipids

66
Q

Ribosomes

A

• complex structures consisting of protein and

RNA

67
Q

Ribosomes site of

A

protein synthesis

68
Q

Ribosomes

p vs e

A

prokaryotic are smaller than eukaryotic ribosomes

69
Q

– prokaryotic ribosomes =

A

70S

70
Q

– eukaryotic ribosomes =

A

80S

71
Q

S =

A

Svedburg unit

72
Q

The Nucleoid (3)

A

• irregularly shaped region
• location of chromosome
– usually 1/cell
• not membrane bound

73
Q
In actively
growing cells,
the nucleoid
has projections;
these probably
contain
A

DNA
being actively
transcribed

74
Q

The prokaryotic chromosome (3)

A

• a closed circular, double-stranded DNA
molecule
• looped and coiled extensively
• nucleoid proteins probably aid in folding

75
Q

– nucleoid proteins differ from —

A

histones

76
Q

some prokaryotes have > - chromosome

A

1

77
Q

some prokaryotes have chromosomes

composed of

A

linear double-stranded DNA

78
Q

a few genera have — nucleoids

A

membrane-delimited

79
Q

Plasmids (4)

A
• usually small, closed circular DNA
molecules
• exist and replicate independently of
chromosome
• not required for growth and reproduction
• may carry genes that confer selective
advantage (e.g., drug resistance)
80
Q

The Prokaryotic Cell Wall

A

• rigid structure that lies
just outside the plasma
membrane

81
Q

Functions of cell wall (4)

A
  • provides characteristic shape to cell
  • protects the cell from osmotic lysis
  • may also contribute to pathogenicity
  • may also protect cell from toxic substances
82
Q

Bacteria are divided into two major groups
based on the response to Gram-stain
procedure

A

– gram-positive bacteria stain purple

– gram-negative bacteria stain pink

83
Q

• staining reaction due to

A

cell wall structure

84
Q

Periplasmic space

A

• gap between plasma membrane and cell
wall (gram-positive bacteria) or between
plasma membrane and outer membrane
(gram-negative bacteria)

85
Q

periplasm

A

– substance that occupies periplasmic space

86
Q

Periplasmic enzymes

• found in

A

periplasm of gram-negative

bacteria

87
Q

Periplasmic enzymes fxn (4)

A

– nutrient acquisition
– electron transport
– peptidoglycan synthesis
– modification of toxic compounds

88
Q

Exoenzymes (2)

A

• secreted by gram-positive bacteria
• perform many of the same functions that
periplasmic enzymes do for gram-negative
bacteria

89
Q

Peptidoglycan Structure (3)

A

• important component of both gram-positive
and gram-negative bacteria
• polysaccharide formed from peptidoglycan
subunits
• two alternating sugars form backbone

90
Q

two alternating sugars form backbone (2)

A

– N-acetylglucosamine

– N-acetylmuramic acid

91
Q

Gram-Positive Cell Walls (2)

A
• composed primarily
of peptidoglycan
• also contain large
amounts of teichoic
acids
92
Q

teichoic acids

A

• polymers of glycerol
or ribitol joined by
phosphate groups

93
Q

Gram-Negative Cell Walls (3)

A

• consist of a thin layer of peptidoglycan
surrounded by an outer membrane
• outer membrane composed of lipids,
lipoproteins, and lipopolysaccharide (LPS)
• no teichoic acids

94
Q

Braun’s lipoproteins connect outer

membrane to —

A

peptidoglycan

95
Q

Adhesion sites (2)

A

– sites of direct contact (possibly true membrane
fusions) between plasma membrane and outer
membrane
– substances may move directly into cell through
adhesion sites

96
Q

Lipopolysaccharides (LPSs)

• consist of three parts

A

– lipid A
– core polysaccharide
– O side chain (O antigen)

97
Q

Importance of LPS (4)

A

• protection from host defenses (O antigen)
• contributes to negative charge on cell
surface (core polysaccharide)
• helps stabilize outer membrane structure
(lipid A)
• can act as an endotoxin (lipid A)

98
Q

Other characteristics of outer
membrane
• more permeable than plasma membrane due
to presence of

A

porin proteins and transporter

proteins

99
Q

porin proteins form channels through which

A

small molecules (600-700 daltons) can pass

100
Q

Capsules, Slime Layers, and SLayers

• layers of material lying — the cell wall

A

outside

101
Q

capsules (2)

A
  • usually composed of polysaccharides

* well organized and not easily removed from cell

102
Q

slime layers (1)

A

• similar to capsules except diffuse, unorganized and

easily removed

103
Q

glycocalyx (2)

A

– network of polysaccharides extending from the
surface of the cell
– a capsule or slime layer composed of
polysaccharides can also be referred to as a
glycocalyx

104
Q

More functions of outer membrane (4)

A

• protection from viral infection or predation
by bacteria
• protection from chemicals in environment
(e.g., detergents)
• motility of gliding bacteria
• protection against osmotic stress

105
Q

fimbriae (2)

A

– short, thin, hairlike, proteinaceous appendages
• up to 1,000/cell
– mediate attachment to surfaces

106
Q

sex pili (2)

A
– similar to fimbriae except longer, thicker, and
less numerous (1-10/cell)
– required for mating
107
Q

• monotrichous –

A

one flagellum

108
Q

• polar flagellum –

A

flagellum at end of cell

109
Q

amphitrichous –

A

one flagellum at each end

of cell

110
Q

lophotrichous –

A

cluster of flagella at one or

both ends

111
Q

peritrichous –

A

spread over entire surface of

cell

112
Q

Flagellar Ultrastructure

• 3 parts

A

– filament
– basal body
– hook

113
Q

The Bacterial Endospore (3)

A

• formed by some bacteria
• dormant
• resistant to numerous environmental
conditions

114
Q

resistant to numerous environmental

conditions (4)

A

– heat
– radiation
– chemicals
– desiccation

115
Q

An Overview of Eukaryotic Cell Structure (4)

A
• membrane-delimited nuclei
• membrane-bound organelles that
perform specific functions
• more structurally complex than
prokaryotic cell
• generally larger than prokaryotic
cell
116
Q

The Endoplasmic Reticulum

A
irregular network of
branching and
fusing membranous
tubules and
flattened sacs
(cisternae – s.,
cisterna)
117
Q

rough (granular) ER (2)

A

– ribosomes attached

– synthesis of secreted proteins by ER-associated ribosomes

118
Q

smooth (agranular) ER (2)

A

– devoid of ribosomes

– synthesis of lipids by ER-associated enzymes

119
Q

Functions of ER (3)

A

– transports proteins, lipids, and other materials within cell
– major site of cell membrane synthesis
– synthesis of lysosomes

120
Q

The Golgi Apparatus

A

• membranous organelle
made of cisternae
stacked on each other

121
Q

dictyosomes

A

– stacks of cisternae

122
Q

The Golgi Apparatus

• involved in (3)

A

modification,
packaging, and
secretion of materials

123
Q

lysosomes (2)

A

– membrane-bound vesicles
– contain hydrolytic enzymes needed for
digestion of macromolecules

124
Q

endocytosis

A

– uptake of solutes or particles by enclosing them
in vesicles or vacuoles pinched off from the
plasma membrane

125
Q

• Phagocytosis –

A

particles or bacterial cells

126
Q

• Pinocytosis -

A

solutes

127
Q

Mitochondria (2)

A
• site of tricarboxylic
acid cycle activity
• site where ATP is
generated by
electron transport
and oxidative
phosphorylation
128
Q

Mitochondrial structure (3)

A
  • outer membrane
  • inner membrane
  • matrix
129
Q

inner membrane (2)

A

– highly folded to form cristae (s., crista)
– location of enzymes and electron carriers for electron transport and
oxidative phosphorylation

130
Q

matrix (2)

A

– contains ribosomes, mitochondrial DNA, and large calcium
phosphate granules
– contains enzymes of the tricarboxylic acid cycle and the β- oxidation pathway for fatty acids

131
Q

nucleus

A

– membrane-bound structure that

houses genetic material of cell

132
Q

chromatin (3)

A

– dense fibrous material within nucleus
– contains DNA
– condenses to form chromosomes
during cell division

133
Q

nuclear envelope (2)

A

– double membrane structure that
delimits nucleus
– penetrated by nuclear pores

134
Q

pores allow materials to be

A

transported into or out of nucleus

135
Q

The molecular unity of

prokaryotes and eukaryotes (3)

A
  • same basic chemical composition
  • same genetic code
  • same basic metabolic processes