1
Q
This field of science is all about microorganisms
A
Microbiology
2
Q
Microbes are a diverse group of generally minute, simple life-forms that include:
A
- Bacteria
- Algae
- Fungi
- Protozoa
- Archaea
- Viruses
3
Q
2 interconnected themes that the science of microbiology revolves around:
A
- Understanding the nature and functioning of the microbial world
- Applying our understanding of the microbial world for the benefit of humankind and planet earth
4
Q
Evidence shows that microbial cells first appeared between…?
A
3.8 and 3.9 billion years ago
5
Q
Group of cells derived from a single parental cell by successive cell divisions
A
Population
6
Q
Immediate environment in which microbial population lives
A
Habitat
7
Q
Population of cells interact with other populations
A
Microbial communities
8
Q
Microbe that live in extreme heat
A
Hyperthermophile (archaea)
9
Q
Microbe that lives in extreme cold
A
Psychrophile (eubacteria)
10
Q
Microbe that lives in low pH
A
Acidophile (archaea)
11
Q
Microbe that lives in high pH
A
Alkaliphile (archaea)
12
Q
Microbe that lives in extreme pressure
A
Barophile (piezophile) (eubacteria)
13
Q
Microbe that lives in extreme salt
A
Halophile (archaea)
14
Q
Impact of microorganisms on humans:
A
- Produce valuable human products
- Generate energy
- Clean up the environment
15
Q
Microbial ecosystem in which large population of microorganisms digest and ferment cellulose
A
Rumen
16
Q
Microbial cell pH level and microbe growth in the digestive system:
A
- Stomach (pH 2) = low
- Small intestine (pH 5) = about 108/g
- Colon (pH 7) = maximal numbers
17
Q
A group of archaebacteria that produces methane (CH4) through anaerobic metabolism
A
Methanogens
18
Q
Microorganisms can be used to clean up pollution in a process called?
A
Bioremediation
19
Q
Elements of microbial structure:
A
- Cell wall
- Cytoplasmic membrane
- Nucleoid
- Cytoplasm
- Plasmid
- Ribosomes
20
Q
Separates the inside of the cell from the outside
A
Cytoplasmic membrane
21
Q
An aqueous mixture of macromolecules, small organic molecules, various inorganic ions, and ribosomes
A
Cytoplasm
22
Q
Lends structural strength to a cell; is a relatively permeable structure located outside the membrane
A
Cell wall
23
Q
Circular, double stranded piece of DNA, not surrounded by a nuclear membrane
A
Nucleoid
24
Q
Small, circular, independent double-stranded DNA molecule. Can frequently be transmitted from one bacterium to another
A
Plasmid
25
Has a single circular chromosome of 4,639,221 base pairs of DNA arranged into 4288 genes
Escherichia coli
26
Activities of microbial cells:
- Growth
- Metabolism
- Motility
- Differentiation
- Evolution
- Communication
27
An illness from an infection with the RABV virus
Rabies
28
A bacterial infection caused by Mycobacterium tuberculosis that can affect your lungs or other organs
Tuberculosis
29
First to describe microorganisms in his famous book “Micrographia” where he illustrated the fruiting structures of mold
Robert Hooke
30
The first person to see bacteria
Antoni van Leewenhoek
31
Constructed extremely simple microscopes containing a single lens to examine various natural substances for microorganisms
Antoni van Leewenhoek
32
Botanist, and his interest in microscopy led him to the study of unicellular algae and later to bacteria, including large sulfur bacterium Beggiotoa
Ferdinand Cohn
33
Effective methods for preventing the contamination of culture media such as the use of cotton for closing flasks and tubes
Ferdinand Cohn
34
First medical microbiologist
Robert Koch
35
Made rapid progress in the isolation and characterization of several disease-causing bacteria
Robert Koch
36
Associate of Robert Koch, developed the transparent, double-sided dish that quickly became the standard tool for obtaining culture
Richard Petri (petri dish)
37
Initiated studies on the mechanism of the alcoholic fermentation, which in the nineteenth century was assumed to be a strictly chemical process
Louis Pasteur
38
What year did Louis Pasteur counter their objection simply and brilliantly by constructing a swan-necked flask, now called a Pasteur flask
1864
39
Louis Pasteur also developed:
Vaccines for anthrax, fowl cholera, and rabies
40
Pasteur’s fame from his rabies research was legendary and led the french government to establish…
Pasteur Institute in Paris in 1888
41
First administration of a rabies vaccine to a human
July 1885
42
If a bacteria is grown away from other bacteria, it is called?
Pure culture
43
Minute living things that individually are usually too small to be seen with the unaided eye
Microbes
44
Anatomy of Eukaryotic Cell:
- DNA usually found in the cell’s nucleus
- DNA is associated with histones
- Membrane-enclosed organelles
- Cells walls, when present, are chemically simple
- Cell division usually involves mitosis
45
Anatomy of Prokaryotic Cell:
- DNA is NOT enclosed within a membrane and is usually a singular circularly arranged chromosome
- DNA is not associated with histones
- Lack membrane enclosed organelles
- Cell walls almost always contain the complex polysaccharide structure
- Usually divide by binary fission
46
Major cell morphologies:
- Coccus
- Rod
- Spirilla
47
Spherical or ovoid
Coccus
48
Cylindrically shaped cell
Rod
49
Some rods form spiral shapes called __
Spirilla
50
Cell shape
Morphology
51
Largest known prokaryote
Thiomargarita namibiensis
52
Small cells have __ surface-to-volume ratio
Higher
53
The more chromosome replications that occur, the greater the total number of __ in the cell population
Mutations
54
The “raw material” of evolution
Mutation
55
If this is compromised, the integrity of the cell is destroyed
Cytoplasmic membrane
56
The general structure of the cytoplasmic membrane is a?
Phospholipid bilayer
57
Phospholipid are composed of:
- Hydrophobic tail (fatty acid)
- Hydrophilic head (glycerol-phosphate)
58
Sterol-like molecules that function to strengthen the membranes of bacteria
Hopanoids
59
Sterol in plants
Phytosterol
60
Sterol in fungi
Ergosterol
61
Sterol in animals
Cholesterol
62
Protein that is firmly i
embedded in the membrane
Integral membrane protein
63
Typically interact with integral membrane proteins in important cellular processes such as energy metabolism and transport
Peripheral membrane proteins
64
One substance that freely pass the membrane in both directions
Water
65
Equal solute concentration
Isotonic
66
Lower solute concentration
Hypotonic (water moves into the cell)
67
Higher solute concentration
Hypertonic (water moves out of the cell)
68
100% permeability or can move in/out of the cell
Water, oxygen, carbon dioxide
69
Function to accumulate solutes against the concentration gradient
Transport proteins
70
High to low and doesn’t require energy
Along the concentration gradient
71
Low to high and requires energy (ATP) for transport
Against the concentration gradient
72
Consist only of a membrane spanning transport protein
Simple transport
73
Employs a series of proteins in the transport event
Group translocation
74
Three components of ABC transport system:
1. Substrate-binding protein
2. Membrane integrated transporter
3. ATP-hydrolyzing protein
75
Consist of 3 components: a substrate-binding protein, a membrane integrated transporter, and an ATP-hydrolyzing protein
ABC transport system
76
Are proteins that carry a substance unidirectionally across the membrane, either in or out
Uniporters
77
Are co-transporters; they transport a molecule along with a second substance, typically a proton
Symporters
78
Proteins that transport one substance into the cell while simultaneously transporting a second out of the cell
Antiporters
79
A region in a gram-negative bacteria that lies between the cytoplasmic membrane and a second membrane layer
Periplasm
80
The periplasm contains many different proteins, several which function in transport and are called __
Periplasmic binding proteins
81
As much as __% of the gram-positive cell wall is composed of peptidoglycan. While gram-negative cell wall consists of at least __ layers
90%
2 layers
82
Two sugar derivatives of peptidoglycan and their glycosidic bond
N-acetylglucosamine, N-acetylmuramic acid B-1,4
83
Backbone of pseudomurein and its glycosidic bond
N-acetylglucosamine, N-acetyltalosaminuronic acid B-1,3
84
Peptidoglycan can be destroyed by certain agents, such as __
Lysozyme
85
The outer membrane is relatively permeable to small molecules because if proteins called __ that function as channels for the entrance and exit of solutes
Porins
86
Similar to peptidoglycan, a polysaccharide called __ is present in cell walls of certain methanogenic bacteria
Pseudomurein
87
Always the outermost wall layer, the layer that is in direct contact with the environment
S-layer
88
If the layer is organized in a tight matrix that excludes small particles, such as india ink, it is called a?
Capsule
89
Enables cells to stick to surfaces, including animal tissues in the case of pathogenic bacteria
Fimbriae
90
Two very important functions of pili:
1. Facilitating genetic exchange between cells in a process called conjugation
2. Enabling the adhesion of pathogens to specific host tissues that they invade
91
Highly differentiated cells that are extremely resistant to heat, harsh chemicals, and radiation
Endospores
92
2 grouping system (plants/animals)
Aristotle
93
Proposed a third kingdom, which he called protista
Ernst Haeckel (1834-1919)
94
Proposed a four-kingdom scheme, the kingdom Monera (prokaryotic organisms; bacteria and blue-green algae)
Herbert Copeland (1902-1968)
95
A French marine biologist introduced the terms prokaryotes and eukaryotes in 1937
Edouard Chatton (1883-1947)
96
Proposed a fifth kingdom called kingdom fungi
Robert Whittaker (1969)
97
Proposed the division of prokaryotes into eubacteria and archaebacteria
Carl Woese
98
Woese’s Six-Kingdom Classification System:
- Kingdom Animalia
- Kingdom Plantae
- Kingdom Protista
- Kingdom Fungi
- Kingdom Eubacteria
- Kingdom Archaebacteria
99
American biologist who proposed the creation of new taxon called Domain in 1990, a rank higher than Kingdom
Carl Woese
100
3 domains:
1. Domain Bacteria
2. Domain Archaea
3. Domain Eukarya
101
This group includes all prokaryotic single-celled bacteria whose cell walls are composed of a polysaccharide called peptidoglycan
Domain bacteria
102
Organisms that are classified under this domain are perceived to be more primitive; they live in extreme environmental conditions
Domain archaea
103
The main characteristic of the members of this group is the presence of membrane-bound nucleus and other membrane-bound organelles
Domain eukarya
104
Energy yielding reactions are a part if metabolism called __
Catabolism
105
Organisms that conserve energy from chemicals
Chemotrophs
106
Use organic chemicals
Chemoorganotrophs
107
Inorganic compounds are oxidized
Chemolitotrophs
108
Classified as sulfur bacterium
Thiomargarita namibiensis
109
Convert light energy into chemical energy
Phototrophs
110
Contain pigments that allow them to convert light energy to chemical energy
Phototrophic microorganisms
111
Oxygen is produced
Oxygenic photosynthesis (cyanobacteria, and algae)
112
Does not yield O2
Anoxygenic photosynthesis (purple and green bacteria and the heliobacteria)
113
Its cell carbon is obtained from some organic chemica
Heterotroph (chemoorganotroph)
114
Uses CO2 as its carbon sourced
Autotrophs (chemolitotrophs, and phototrophs)
115
Are substances that can speed up chemical reactions without being altered
Catalysts
116
Serve as biological catalysts, act on a specific substance
Enzymes
117
Specific substance that enzymes act on
Enzyme subtrate
118
Protein portion (inactive)
Apoenzyme
119
Nonprotein portion (activator)
Cofactor
120
Whole enzyme (active)
Holoenzyme
121
Apoenzyme + Cofactor (coenzyme) -> __
Holoenzyme
122
Factors influencing enzymatic activity
- Temperature
- pH
- Substrate concentration
123
Metabolic reactions that involve the transfer of electrons from one molecule to another
Oxidation-Reduction reaction or Redox reaction
124
Maximum rate of enzymatic activity can be obtained when there is a high __
Substrate concentration
125
When a molecule loses an electron, it is said to be __
Oxidized
126
When an electron is gained, the recipient is __
Reduced
127
In photosynthesis, __ is oxidized, and __ is reduced
Water, glucose
128
When biological oxidations involve the loss of hydrogen atoms
Dehydrogenation reactions
129
Means attaching a phosphate group ((PO4)^3) to an ion or molecule
Phosphorylation
130
The breakdown of carbohydrate molecules to produce energy
Carbohydrate catabolism
131
The most common carbohydrate energy source used by cells
Glucose
132
To produce energy from glucose, microorganisms use two general processes:
- Cellular respiration
- Fermentation
133
Within each plant cell, glucose abd other fuel molecules are broken down during __
Cellular respiration
134
Cells that live in environments where oxygen is plentiful to use
Aerobic pathway
135
Cell that live on oxygen-poor environment must use __
Anaerobic pathway
136
In anaerobic pathways, the final electron acceptor is
- Nitrate (NO3)
- Sulfate (SO4^2)
137
Degrades glucose and other organic molecules without oxygen
Fermentation
138
Two common types of fermentation
- Alcoholic fermentation
- Lactate fermentation
139
Degrade glucose and pyruvate through glycolysis
Alcoholic fermentation
140
Pyruvate produced from glycolysis is converted to lactate
Lactate fermentation
141
Alcoholic fermentation:
Glucose is converted to pyruvate through glycolysis. Pyruvate is converted to acetaldehyde which finally turns into ethanol (ethyl alcohol)
142
Lactate fermentation:
Glucose is broken down into pyruvate and is directly converted to lactate
143
Requirements for Growth:
Physical requirements
- Temperature
- pH
- Osmotic pressure
Chemical requirements
- Carbon
- Nitrogen, Sulfur, and Phosphorus
- Oxygen
144
Moderate temperature loving microbes
Mesophiles
145
Temperature - best growth
Optimum temperature
146
The most common method for preserving food
Refrigeration
147
Few bacteria grow at an ___
Acidic pH (
148
Most bacteria grow best
pH 6.5 to 7.5
149
Inhibits microbial growth
Alkaline
150
__% water concentration optimum for most bacteria
80-90%
151
Osmotic loss of water or shrinkage of the cell’s cytoplasm
Plasmolysis
152
Adapted to high salt concentration
Obligate Halophiles
153
Do not require high salt concentration (able to grow at salt concentration up to 2%)
Facultative Halophiles
154
One of the most important for microbial growth requirement
Carbon
155
Protein synthesis
Nitrogen
156
Synthesize sulfur-containing amino acids and vitamins such as thiamine and biotin
Sulfur
157
Synthesis of nucleic acids and phospholipids of cell membranes
Phosphorus
158
Different tolerance of microorganisms to Oxygen
- Obligate aerobes
- Obligate anaerobes
- Facultative anaerobes
- Aerotolerant anaerobes
159
Organisms that require oxygen to live
Obligate Aerobes
160
Can use oxygen when it is present but are able to continue growth by using fermentation or anaerobic respiration when oxygen is not available
Facultative Anaerobes
161
Unable to use oxygen for energy yielding reactions
Obligate Anaerobes
162
Cannot use oxygen for growth but they tolerate it fairly well
Aerotolerant Anaerobes
163
Culture media:
- Chemically defined media
- Complex media
- Anaerobic growth media
- Special culture techniques
- Selective and differential media
- Enrichment culture
164
Prepared by adding precise amounts of pure inorganic or organic chemicals to distilled water
Chemically defined media
165
Is made up of nutrients including extracts from yeast, meat, or plants
Complex media
166
If a complex medium is in liquid form
Nutrient broth
167
A complex medium in solid form due to addition of agar
Nutrient agar
168
Contain the nutrients sodium thioglycolate + dissolved oxygen (deplete the oxygen in the culture medium)
Reducing media
169
Use tightly capped test tubes to maintain pure cultures of obligate anaerobes
Anaerobic growth media
170
Some bacteria are cultured in a living host cell; or use special carbon dioxide incubators
Special culture media
171
Use to suppress the growth of unwanted bacteria and encourage the growth of the desired mucrobes
Selective media
172
Use to distinguish colonies of the desired organism from other colonies growing on the same plate
Differential media
173
Use to isolate gram negative Salmonella typhi from feces
Bismuth sulfite agar
174
Use to identify bacterial species that destroy red blood cells
Blood agar medium
175
Is a selective and differential agar used to recover Salmonella and Shigelia
Hektoen Enteric Agar
176
Discourage the growth of other microorganisms and favor the growth of S. aureus
High sodium chloride and mannitol salt agar
177
Is used when desired bacteria is in a small numbers out of large numbers
Enrichment culture (alkaline peptone water formato)
178
The time required for a cell to divide
Generation time
179
Phases of Growth
1. Lag phase
2. Log phase
3. Stationary phase
4. Death or decline phase
180
Period of little or no cell division
Lag phase
181
Cells begin to divide and enter the period of growth or increase
Log phase
182
Is the period of equilibrium; rate of cell division and death roughly equal
Stationary phase
183
When number of deaths exceed new cells
Death phase
184
Physical controls of microbial growth:
- Heat sterilization
- Autoclave and pasteurization
- Ultraviolet and ionizing radiation
185
Chemical controls of microbial growth:
1. Sterilants
2. Disinfectants
3. Sanitizers
4. Antiseptics
186
Destroy all microorganisms, including endospores; used for decontamination
Sterilants
187
Are chemicals that kill microorganisms but not necessarily endospores and are used on inanimate objects
Disinfectants
188
Are less harsh chemicals than disinfectants and function to reduce microbial numbers but not necessarily sterilize the object
Sanitizers
189
Are chemicals that kill or inhibit growth of microorganisms but are sufficiently nontoxic to animals to be applied to living tissues
Antiseptics
190
An anabolic, endergonic, CO2 requiring process that uses light energy (photons) and H2O to produce organic macromolecules (glucose)
Photosynthesis
191
Complete equation of photosynthesis
6CO2 + 6H2O + Light energy -> C6H12O6 + 6O2
192
Photosynthesis is a redox process where __ is oxidized and __ is reduced
Water, carbon dioxide
193
Adding O, removing H, loss of electrons, exergonic (releases energy)
Oxidation
194
Removing O, adding H, gain of electrons, endergonic (stores energy)
Reduction
195
Can use diverse electron donors but cannot use water
Anoxygenic phototrophs
196
Site of photosynthesis
Chloroplast
197
Membrane-bound compartments inside chloroplasts and cyanobacteria
Thylakoid
198
Chloroplast is derived from __
Cyanobacteria
199
Stack of thylakoid
Granum/grana
200
Space between granum, outside thylakoid
Stroma
201
Thylakoid space
Lumen
202
2 processes of photosynthesis:
1. The light reactions (light-dependent, photochemical processes)
2. The dark reactions (light-independent or carbon fixation processes)
203
Conversion of light (solar) energy to chemical energy (ATP and NADPH)
The light reactions
204
Consists of certain particles called photons
Light
205
Includes the colors of light we can see
Visible light spectrum (380-750 nm)
206
Photosynthetic pigments:
- Chlorophyll
- Chlorophyll a
- Chlorophyll b
- Carotenoids
207
Main photosynthetic pigment; found in all autotrophic organisms efficient in absorbing blue and red regions of the visible spectrum
Chlorophyll
208
Absorb different wavelengths of light and pass the energy to chlorophyll a
Accessory chlorophyll pigments
209
A pigment that initiates photosynthesis
Chlorophyll a
210
Pigment in all true plants
Chloropyll b
211
Pigment, yellow and orange
Carotenoids
212
This is where the photosynthetic pigments are contained
Thylakoids
213
Light energy is converted to chemical energy
Light-dependent reactions
214
Uses carbon dioxide; energy molecules from light dependent reactions are used to build high-energy compounds (carbohydrates)
Light-independent reactions
215
The light-dependent reaction occurs in the __
Thylakoid membrane
216
Contains pigment-binding proteins where chlorophyll and accessory pigments are attached
Antenna complex
217
Reaction centers:
1. Photosystem II (P680)
2. Photosystem I (P700)
218
Electron transport chain occurs; NADPH and ATP will form
Photosystem I
219
H2O is oxidized; oxygen molecule is produced
Photosystem II
220
Formation of ATP is known as?
Chemiosmosis
221
The ultimate structure for capturing energy from low light
Chlorosome
222
Also known as carbon fixation; uses the energy produced in light-dependent stage for producing carbohydrates in large amounts, as stored energy for future use
Light-independent reaction
223
Light independent phase occurs in the __
Stroma
224
3 Phases of the Calvin Cycle:
1. CO2 uptake
2. Carbon reduction
3. RuBP regeneration
225
Calvin cycle is named after the scientist __
Melvin Calvin
2C
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