Chapter 1: Intro to Microbiology Flashcards
(179 cards)
1
Q
What is microbiology?
A
The study of the microbial world
2
Q
What are microorganisms?
A
Living organisms that include bacteria, protozoa, fungi and some algae that are not visible to the the naked eye.
cellular in structure
3
Q
What is a microbe?
A
Includes all microorganisms along with viruses and prions
Viruses and prions are not made up of living organisms
4
Q
Who is Robert Hooke?
A
1665 English Scientist
5
Q
Who is Anthony van Leeuwenhoek?
A
1674 Dutch fabric merchant
6
Q
What are living microorganisms?
A
Bacteria, protozoa, fungi, and some algae
7
Q
What helped develop the scientific method?
A
Spontaneous generation
8
Q
Who made the first “microscope” and observed animalcules?
A
Leeuwenhoek
9
Q
Who hypothesized that invisible organisms may cause disease?
A
Fracastoro
10
Q
Who made the first “modern microscope” and coined the word “cell”?
A
Hooke
11
Q
What scientist created the “swan neck flask” experiment?
A
Pasteur
12
Q
Who formulated the germ theory of disease?
A
Pasteur
13
Q
Who discovered penicillin?
A
Hooke
14
Q
Who studied causative agents of disease?
A
Robert Koch
15
Q
What is the gold standard for determining disease causation?
A
- The same organism must be present in every case of the disease
- The organism must be isolated from the diseased host and grown in pure culture
- isolate must cause disease in healthy host
- must be re-isolated from diseased host
16
Q
Who disproved Pasteur about spontaneous generation?
A
John Tyndall and Ferdinand Cohn
17
Q
Who discovered endospores?
A
Ferdinand Cohn
18
Q
What is etiology?
A
causative agents of disease
19
Q
Who discovered agars?
A
Robert Koch
20
Q
What did Robert Koch do?
A
- first pictures of bacteria
- staining techniques
3.use of steam to sterilize - petri dishes
- sterile lab techniques to transfer bacteria
21
Q
What does zoonotic mean?
A
comes from animals
22
Q
What are the good parts of microbes?
A
nitrogen fixing
carbon fixing
photosynthesis
decomposition
fermentation
bioremediation
digestion
23
Q
What is nitrogen fixing?
A
-Process by which nitrogen gas (N2) is converted into ammonia (NH3)
-Nitrogen can then be incorporated into cellular material (amino acids-protein)
24
Q
What is fermentation?
A
-Lactic acid producing bacteria
-Cheese, pickles, sour kraut
-Wine, beer
25
What is bioremediation?
-Use of microorganisms to remove toxins and pollutants from the environment
-Water waste treatment
-Oil spills
26
What are prokaryotes?
bacteria and archaea
27
What is the difference between bacteria and archaea?
Bacteria- have peptidoglycan cell walls
Archaea- don't have peptidoglycan or cell walls
28
What constitutes a nomenclature name?
1) Capitalized genus
2) Lowercase species
29
How is prokaryotic digestion different from eukaryotic?
Prokaryotic bacteria secrete digestive enzymes out of the cell to get macromolecules and deposit pieces back into the cell.
30
What are bacteria?
gram positive and gram negative
31
What is an example of an archaea?
halophiles
32
What are some examples of eukarya?
Fungi, animals, plants, algae, and protozoa
33
What do bacteria have?
1. no nuclear membrane
2. cell wall/ peptidoglycan
3. ubiquitous
4. no membrane-bound organelles
34
What do archaea have?
1. no nuclear membrane
2. no peptidoglycan
3. ubiquitous
4. no membrane bound organelles
35
What do eukarya have?
1. nuclear membrane
2. no peptidoglycan
3. membrane bound organelles
4. non-extreme environments
36
What does ubiquitous mean?
can live in almost any environment
37
What do algae have/ do?
1. single-celled and multicellular
2. photosynthetic
3. primarily aquatic
38
What do fungi have/do?
1. single celled and multicellular
2. degradation/fermentation
3. primarily terrestrial
39
What do protozoa have/do?
1. single celled
2. found anywhere
40
What are some non-living organisms?
Viruses, viroids, and prions
41
What describes a virus?
-RNA or DNA
-protein coats
-obligate intracellular pathogen
-infect plants, animals and microorganisms
42
What describes viroids?
-short RNA
-no protein coat
-infect plants
43
What describes prions?
-protein
-transfer a misfolded protein to healthy proteins
44
What is the cell structure of a prokaryote?
Cell envelope
-cytoplasmic membrane
-cell wall
-possibly a capsule
45
What does the cytoplasmic membrane of prokaryotes contain/do?
-separates in from out
-phospholipids
-trans-membrane proteins
---gates nutrients and waste
--- fluid mosaic model
-selectively permeable through simple diffusion
---gases
---water by osmosis
---small hydrophobic molecules
46
How does water diffuse through the cytoplasmic membrane of a prokaryote?
water moves from hypotonic to hypertonic through osmosis
47
How does transport work in the cytoplasmic membrane?
Transport is performed by proteins embedded in the membrane
48
What is transported through the cytoplasmic membrane?
enzymes and extracellular proteins
49
What are enzymes?
secreted to digest saccharides that the cell can take in for nutrients
50
What does extracellular proteins do?
used for flagella and other proteins for motility
51
What is NAG?
N-acetylglucosamine
52
What is NAM?
N-acetylmuramic acid
53
What are NAG and NAM similar to?
glucose
54
What is NAM linked by?
linked by a peptide interbridge in gram + bacteria
55
What is NAM linked by?
has a tetrapeptide chain that directly links in gram -
56
List 5 characteristics of gram-positive bacteria
1. Thick layer of peptidoglycan
2. Teichoic Acids
3. Single inner membrane
4. Gel membrane underneath peptidoglycan layer
5. NAG-NAM cross bridge
57
List 5 characteristics of gram-negative bacteria
1. Thin layer of peptidoglycan
2. Porins
3. Two membranes, with periplasmic space in between
4. LPS (endotoxin PAMP)
5. NAG-NAM direct linkage
58
What is lipid A?
an endotoxin which causes inflammation
59
Where are porins in a gram - bacteria?
in the upper membrane
60
Differentiate capsules, slime layers, and biofilms
A: A gel capsule is a gel-like layer for protection/adherence (whipped cream)
B: Slime layers + Capsules contain glycocalyx (sugar shell), providing uniform, strong protection. (icing)
C: Biofilm: Polymer-encased community. Many layers. (Bunker for protection) Example: dental plaque
61
What is the importance of pili?
Pili help bacteria adhere to specific surfaces and move on solid surfaces. They also facilitate DNA transfer. Hide close to the surface to avoid leukocytes.
62
What is the functions of periplasm in gram - bacteria?
-nutrient degradation
-enzyme secretion
-electron transport
-xenobiotic metabolism
has the same function as the gel-like layer of gram + peptidoglycan layer
63
What is LPS?
lipopolysaccharide which is also an endotoxin
64
What is in a LPS?
O antigen and lipid A
65
Where is lipid A in LPS?
Anchored in the outer membrane
66
Where is the O antigen in LPS?
outer portion and is variable among bacteria
67
What are plasmids?
Plasmids are small loops of extra DNA that aren't part of the chromosome. Plasmids contain genes for things like drug resistance and can be passed between bacteria.
68
What constitutes an endospore?
Sugar + Chromosome + Protein
69
What key features help differentiate eukaryotic cells from prokaryotic cells?
Eukaryotic: membrane-bound organelles (mostly), nucleus, most lack cell walls, plant cell walls have chitin and cellulose, single chromosome versus multiple.
70
What is different about eukaryotic cytoplasmic membrane transports compared to prokaryotes?
Eukaryotes can perform endocytosis, exocytosis, and fusion with lysosomes.
71
What eukaryotic structure is similar to cyanobacteria?
Chloroplasts. Plants and algae have mitochondria and chloroplasts.
72
What was Leeuwenhoek's contribution to the science of microbiology?
He developed the first microscope.
73
The investigations of which researcher finally disproved that living organisms can come from nonliving substances?
Pasteur
74
Microbes that cause infectious diseases are called...
Pathogens
75
One of the main differences between a Gram-positive and a Gram-negative bacterial cell wall is that the peptidoglycan portion of a Gram-positive cell wall is _____ as compared to a Gram-negative cell wall.
Thicker
76
The region between the outer and inner membranes of a Gram-negative bacterial cell is known as the __________, and it is the location of nutrient degradation.
Periplasm
77
What does penicillin do?
inhibits the linkage of peptidoglycan. fungal product
78
What does lysozyme do?
hydrolyzes the NAM-NAG linkages. It is the first line of defense. Made int he body
79
True or false
Penicillin and Lysozymes are not more effective against gram + bacteria.
False
80
What are mycoplasms?
They have no cell wall and are difficult to kill
81
What are archaea?
They have a diverse cell wall structure and lack peptidoglycan.
82
________________has a high number of sterols that provide rigidity
cytoplasmic membrane
83
What describes the capsules of the cell envelope of prokaryotic cells?
-gel-like layer for protection and adherence
-Slime layers and capsules are outside the cell wall
-contain glycocalyx
-contain biofilm
84
What is glycocalyx?
a sugar shell
85
What is biofilm?
polymer-encased community
-Ex) dental plaque
86
What are flagella?
-major form of propulsion
-anchored into cytoplasm and cell wall
-Pathogenic bacteria can have powerful flagella that allow them to penetrate host mucus membranes
87
What are flagellum?
-driven by a proton gradient
-have three components
88
What are the three components of flagellum?
1. basal body
2. hook
3. filament
89
What does the basal body do?
anchors flagella to cell wall and cytoplasmic membrane
90
What does the hook do?
connects basal body and filament
91
What is chemotaxis?
movement induced by the sensing of certain chemicals or nutrients
-RUN, TUMBLE, RUN
92
Which direction does the nutrient concentration gradient move in for Chemotaxis?
lower to higher
93
What are pili?
-adherence to specific surfaces
--fimbriae
--pathogenesis
-movement on solid surfaces
94
What does a nucleoid contain?
chromosomes
-circular DNA
-supercoiled
-nucleoid-associated proteins
95
What does a plasmid contain?
Is smaller than chromosomes
-accessory/non-essential
-antibiotic-resistant gene
96
What are ribosomes?
Have two subunits
-50s and 30s = 70s
70s is distinct from the eukaryotic 80s allowing for therapeutic targeting
-phylogenetic identification
97
What are endospores?
-dormant cells
INVINCIBLE
98
What types of bacteria contain endospores?
bacillus, clostridium
99
What do eukaryotes contain in the cell structure?
-organelles
-nucleus
-lack cell wall
-cell wall (chitin, cellulose)
-simple or multicellular
-cytoplasmic membrane
100
What does a eukaryotic cytoplasmic membrane contain?
-lipid and protein composition
-cytoplasmic is different on the inside of the cell than on the outside
-higher variety of receptors for functioning as a cohesive unit
-contain sterols for membrane integrity (cholesterol or ergosterol)
101
What are eukaryotes?
animals, plants, and fungi
102
What are the different ribosomes present in eukaryotes?
60s, 40s, = 80s
103
Do you eukaryotes have a cytoskeleton?
Yes
104
What does the nucleus do?
-DNA storage, RNA synthesis
-linear DNA
--wound around histones
-MITOSIS
-diploid cells
105
What does the mitochondria do?
Synthesizes ATP
106
What does mitochondria and chloroplasts have?
interior folds to maximize surface area and thus maximizing ATP generation
107
What do Chloroplast do?
Synthesize ATP- photosynthesis
-similar to cyanobacteria
108
What is the emdosymbiotic theory?
mitochondria and chloroplasts look and act like prokaryotes. Theory of endosymbiosis suggests they began as symbionts, then became indispensable.
109
What is the ER?
-has ribosomes
-protein synthesis
110
What is the Golgi?
protein modification and delivery
111
What are lysosomes and peroxysomes?
Lysosomes are enzymes
-peroxysomes are a reactive oxygen species
112
How do prokaryotes grow?
binary fission
113
What is binary fission?
-compete doubling
-exponential growth
-generation time
114
What is generation time?
-time it takes for a population to double
-implications for contamination and public health
-growth refers to population not size
115
What is the log phase equation?
Nt = N0 x 2n
exponential
-start with 10 cells
-doubles every 20 minutes
116
What does Nt stand for?
number of cells at a given time
117
What does N0 stand for?
starting number of cells
118
What does n stand for?
number of generations
119
What are the stages of microbial growth and the growth curve?
-lag phase
-log phase
-stationary phase
-death
-prolonged decline
120
What is the lag phase?
-enzyme synthesis
-primary target of drugs
-production of metabolites
121
What is the log phase?
-exponential growth
122
What is the stationary phase?
-exhaustion of nutrients
-find new nutrient option
-take nutrients from dead cells
CANNIBALS
123
What is the death phase?
exponential (slower than growth)
124
What is prolonged decline?
-adaptation to adversity
-population survives death
125
What is EPS?
Extracellular Polymeric Substances
-many are optimized for life in a biofilm
-infections, water systems, environments
126
What are extremophiles?
Dominated by archaea
-temp
-pH
-salt
-water
127
What do salt and sugar react with?
Water, making it unavailable to bacteria
OSMOSIS
128
What is a halotolerant?
tolerates dissolved NaCl up to 10%
129
What is a halophile?
requires NaCl, usually 3% like sea water
130
What is an extreme halophile?
>9% NaCl
131
What is obligate aerobe?
requires O2
132
What is a microaerophile?
2-10% O2 but above that O2 is TOXIC
133
What is facultative anaerobe?
best with O2 but doesn't need it
134
What is obligate anaerobes?
O2 is TOXIC
TOXIC
135
What is aerotolerant anaerobes?
DO NOT USE O2
136
How is oxygen reactive?
-Superoxide dismutase
-catalase (sometimes)
137
What is a carbon source?
-heterotroph
-autotroph
-nitrogen
-phosphorus, Iron
138
What is a heterotroph?
use organic carbon
139
What is a autotroph?
use CO2
-carbon fixation
-plants do the same
140
What does nitrogen do?
-essential component of amino acids
-used to make ammonia
141
What is phosphorus and iron used for?
it is necessary and limited
142
How do phototrophs get energy?
sunlight
143
How do chemotrophs get energy?
chemical compounds
144
What is oxidation?
loss of electrons
145
What is reduction?
gains electrons
146
What reactions will precursor metabolites be used for?
anabolic
147
What are the central metabolic pathways?
1. Glycolysis
2. Pentose Phosphate Pathway (PPP)
3. Tricarboxylic Acid Cycle (TCA) or the Kreb's cycle
148
What happens during the central metabolic pathways?
-ATP by substrate-level phosphorylation
-reducing power in the form of NADH, FADH2, and NADPH (biosynthetic)
-precursor metabolites are produced
149
What is glycolysis?
glucose oxidation in order to obtain ATP
150
What is the pentose phosphate pathway?
synthesis of pentose and release of the reducing power needed for anabolic reactions
151
What is catabolism?
obtaining energy and reducing power from nutrients
152
What is anabolism?
production of new cell components, usually through processes that require energy and reducing power obtained from nutrient catabolism
153
What is the Kreb's cycle?
acetyl-CoA oxidation in order to obtain GTP and valuable intermediates
154
What are some key molecules of the central metabolic pathways?
-glucose
-many enzymes
-Pyruvate/ Acetyl-CoA
-NAD+/ NADH
NADP+/NADPH
-FAD/FADH2
-ATP
155
How are the reactions of metabolism possible?
Through enzymes
156
What are the functions of enzymes?
organic catalysts/rapid acting, regulate all cell activities, and are highly selective
157
What are enzymes?
proteins that speed up chemical reactions
158
What are cofactors?
non-protein assistants (magnesium, copper, zinc, and other trace elements)
159
What are coenzymes?
organic cofactors that loosely carry molecules or electrons, FAD, NAD, NADP, and are often derived from vitamins
160
What are some factors that influence enzyme reactions?
temperature, pH, enzyme and substrate concentrations, and presence of inhibitors
161
As _______ _________ increases, the temperature also increases.
enzyme activity
162
What control enzymatic activity?
activators, inhibitors, and feedback inhibition
163
What are activators?
some enzymes are activated when a cofactor binds to site other than an active site
164
What are inhibitors?
- a substance that blocks enzyme activity
-include competititive and noncompetitive inhibitors
165
What is feedback inhibition?
controls the action of some enzymes
166
Glycocalyces such as capsules help bacteria adhere to a host cell or an environmental surface. What other external structure of bacterial cells help with adherence?
Fimbriae or pili
167
Tetracycline is an antibiotic that targets protein synthesis. Which structure would tetracycline bind to in a bacterial cell?
Ribosome
168
Which of the following statements regarding active transport is false?
It powers the diffusion of water across the cell membrane
169
How are bacteria and archaea different from all other cellular microbes?
They have no nucleus
170
The ________________________ theory explains why mitochondria and chloroplasts have 70S ribosomes and two membranes and DNA.
Endosymbiotic
171
Microbial growth is at its maximum rate during which of the following phases of the microbial growth curve?
log phase
172
A(n) ________ is a complex community of various types of microbes that adhere to surfaces.
biofilm
173
The use of salt and sugar in preserving various types of foods is an application of which of the following concepts?
osmotic pressure
174
A bacterial culture that grows only near the surface of a thioglycolate broth is an example of what type of organism?
obligate aerobes
175
The reactions involved in producing larger compounds from smaller compounds is called
anabolism
176
What is meant by substrate-level phosphorylation?
Production of ATP by transferring phosphates directly from metabolic products (organic molecules) to ADP
177
The final electron acceptor in aerobic respiration is _________________________.
oxygen
178
Redox reactions....
transfer energy, transfer electrons, involve oxidation and reduction
179
What carbon molecules remain at the end of glycolysis
pyruvic acid
