Final Flashcards
(164 cards)
1
Q
Chitin cell walls are characteristic of which taxonomic group?
A
Fungi
2
Q
who is known for realizing that people who had been infected by the Athenian plague had immunity to reinfection?
A
Thucydides
3
Q
Bergey’s Manual of systematic bacteriology is used primarily for..
A
a reference for bacterial classification
4
Q
Describe phylogeny
A
phylogenies show evolutionary relatedness between organisms
5
Q
what produces mycotoxins..
A
Molds
6
Q
Why are viruses not included in phylogenetic trees?
A
They are acellular and nonliving
7
Q
Who is the Swedish botanist known for having developed an important biological classification system?
A
Carolus Linnaeus
8
Q
For taxonomic classification of microbes, serological tests typically are used to do….
A
identify proteins on the basis of their reaction with specific antibodies
9
Q
bacteria are generally identified to species by using…
A
a combination of genetic, biochemical, and microscopic approaches
10
Q
who first observed unicellular organisms, which he called “animalcules”?
A
Antonie Van Leeuwenhoek
11
Q
What is the purpose of a microincinerators?
A
to reduce the risk of open flame, for easy, rapid benchtop sterilization of small pieces
12
Q
what type of organism causes oral thrush?
A
fungi
13
Q
Diatoms are classified within which type of domains?
A
Eukarya
14
Q
Which of the following is true of the microbial world?
A
Many microbes are helpful
15
Q
What is classified distinct from the three-domain system?
A
viruses
16
Q
describe horzontal gene transfer..
A
the transfer of genes from one individual to another, including from one species to another, but not from parent to offspring
17
Q
what are the three currently accepted domains?
A
Archaea, Bacteria, and Eukarya
18
Q
yeast are part of…
A
Unicellular fungi
19
Q
Based just on the name, which of the following groups of bacteria contains entirely species that consume organic compounds for food?
A
nonphotosynthetic bacteria
20
Q
What do the cell walls of archaeans contain?
A
Pseudopeptidoglycan
21
Q
T/F In flurescence, emitted photons have the same amount of energy as absorbed photons.
A
False
22
Q
What structure can negative stains be used to visualize?
A
Capsules
23
Q
T/F Iodine is used for chemical fixation
A
False
24
Q
List the steps to gram staining in order?
A
- Crystal Violet stain
- Iodine mordant
- decolorization
- safranin
25
T/F a wet mount is used when preparing a slide for Gram staining?
False
26
What type of microscopy is best to visualize internal cell structures?
Transmission Slectron Microscopy (TEM)
27
Why are dyes used during microscopy?
to increase contrast
28
T/F A microscope with a very high magnification and low resolution would allow you to clearly see small structures?
False
29
Who first used the term 'cells'
Robert Hooke
30
T/F all cells have cell membranes
True
31
What is the function of the nucleolus within the eukaryotic cells?
It is where ribosomal RNA is synthesized and ribosome assembly begins
32
Which scientist performed an elegant series of experiments that finally and definitively disproved the theory of spontaneous generation?
Louis Pasteur
33
T/F Archael cells contain PTG linkages attaching their membranes to their cell walls
False
34
T/F E. coli is a spore-forming bacterium
false
35
Organelle ribosomes and prokaryotic ribosomes are __, whereas eukaryotic cytoplasmic ribosomes are ___
70s, 80s
36
What is the role of inclusions within Prokaryotic cells
to store excess nutrients
37
When a bacterial cell with a cell wall is placed in salt water with a higher-solute concentration than the cell cytoplasm, the cell will undergo...
Plasmolysis
38
What type of bacteria contain lipopolysaccharide within its cell membrane?
Gram-negative bacteria
39
What type of structures are capsules and slime layers?
glycocalyces
40
Which scientist thought spontaneous generation had occurred in flasks of broth after the broth had been boiled?
John Needham
41
What is the name for a curved rod?
Vibrio
42
What are Koch's postulates?
a series of steps for determining the causative agent of a particular disease
43
Define the theory of spontaneous generation
the idea that life could appear from nonliving materials
44
Where is the bacterial chromosome located?
The nucleoid
45
Which physician realized that doctors were causing maternal deaths by failing to wash their hands while assisting during childbirth?
Ignaz Semmelweis
46
What domains are prokaryotes classified in?
Archaea & Bacteria
47
T/F Mitochondria are a part of the endomembrane system
False
48
List the stages of sporulation
1. DNA replication
2. formation of a double layer of membrane
3. cortex formation
4. spore release
49
How do bacteria use flagella to move purposefully toward or away from a chemical?
by increasing the length of runs and decreasing the length of tumbles
50
How did Joseph Lister dramatically improve surgical outcomes?
by using phenol as an antiseptic and disinfectant during surgery
51
The first known use of epidemiology to trace the source of a disease outbreak was the identification of contaminated water as the cause of cholera transmission in London. which physician accomplished this?
John Snow
52
Reverse transcriptase is used to generate which nucleic acid from RNA?
cDNA
53
An acellular entity composed of a small circular RNA molecule without a capsid and capable of replicating its genome is a...
Viroid
54
Define capsomeres
Capsomeres are protein subunits of nucleic acids
55
Define Induction
the excision of the viral genome from the host chromosome
56
In the lysogenic cycle of bacteriophages, the integrated phage genome is known as...
a prophage
57
What mechanism of horizontal gene transfer relies on the use of viruses?
transduction
58
a novel enzyme found in retroviruses
Reverse transcriptase
59
What is a virusoid?
an acellular entity composed of a small circular RNA molecule without a capsid and it cannot replicate its genome.
60
What is the purpose of fermentation?
To regenerate NAD+
61
which of the following is not a common electron acceptor in anaerobic respiration?
-FE3+
-H2S
-NO3-
-PO43-
PO43- (phosphate ion)
62
what is the net gain for glycolysis production?
2 ATP, 2 NADH, 2 pyruvates
63
What is a common electron acceptor in catabolic reactions?
-ATP
-FADH2
-NAD+
-NADPH
NAD+
64
What type of inhibitor binds to the active site of an enzyme?
a competitive inhibitor
65
define metabolism
all the reactions in a cell or organism
66
T/F Pyruvate is a product of the Krebs cycle
False
67
Where do chemotrophs obtain their energy?
organic & inorganic chemical reactions
68
Describe catabolic pathways
They break down large molecules into smaller components
69
Where do substrates bind to the enzyme?
The active site
70
Define cofactors
Inorganic molecules that bind to enzymes
71
When is ATP produced through oxidative phosphorylation?
When H+ moves through ATP synthase
72
Where is the most acidic location in the mitochondrion?
The intermembrane space
73
What molecule is often called the cell's energy currency?
Adenosine Triphosphate
74
What happens during fixation?
the step when CO2 enters the light-independent reactions (Calvin cycle)
75
Describe a exergonic reaction?
The reaction that breaks down ATP to form ADP and inorganic phosphate
76
Describe a endergonic reaction
it absorbs energy from the environment
77
what group do all lithotrophs belong to?
Microbes
78
When is the pentose phosphate pathway favored over other pathways to break down glucose?
When the synthesis of nucleic acids and proteins is needed
79
In what set of reactions is fatty acids degraded
B-oxidation
80
What enzyme breaks down proteins?
Proteases
81
When happens when a molecule is oxidized?
an electron is removed
82
What happens when molecules are broken down using b-oxidation?
Two carbon acetyl groups are removed
83
Describe the Entner-Doudoroff pathway
It breaks down glucose in some microbes
84
Why is the actual ATP yield of aerobic respiration often less than the maximum possible yield of 38 ATP?
In eukaryotes, energy is used to move molecules across membranes
85
What separates new daughter cells in binary fission?
The division septum
86
Define the inoculum
the initial cells added to a batch culture
87
What is the best choice for distinguishing living & dead bacteria in a cell count
Primary & secondary fluorescent stains
88
What microbial pathogen has an unusually long doubling time?
Mycobacterium leprae
89
What microbe used light energy to pump hydrogen and sodium?
Halobacterium
90
What is the most common category of bacteria?
Neutrophiles
91
why are extracellular polymeric substances important?
They are components of a biofilm secreted by the microbes present
92
List the phases of the growth curve
Lag-->Log-->Stationary-->death/decline
93
What type of microbes thrive in the Great Salt Lake?
extreme halophiles
94
What type of media is commonly used to determine the oxygen requirements of a bacterial species?
Thioglycolate medium
95
What is the goal number of CFUs on a spread plate if a serial dilution is done correctly?
30-300 per plate
96
What is another term for generation time?
doubling time
97
what type of system is used to maintain bacteria in a relatively constant environment, allowing them to stay in the log phase of growth?
chemostat
98
Define persisters
cells with relatively slow metabolic rates that survive longer than others during the death phase and that can cause chronic infections
99
Human pathogens are what type of microbe?
mesophiles
100
How would a microaerophile grow in a thioglycolate tube culture?
A short distance below the top of the medium, but not at the top.
101
List three common ways bacteria can divide
-Binary fission
-budding
-fragmentation
102
Describe FtsZ
a protein that assembles the Z ring, which forms a division before division by binary fission a cytoskeletal protein in eukaryotic cells
103
how do most bacteria commonly reproduce?
binary fission
104
Describe bacterial growth during the log phase of the growth curve?
Exponential
105
T/F Turbidity measurements is an indirect method of measuring numbers of the bacterial cells
True
106
T/F Atmospheric oxygen is a reactive oxygen species
False
107
What are the components of a DNA nuleotide?
A deoxyribose sugar, a phosphate, and a nitrogenous base
108
What does a nucleoside contain?
a sugar and a base
109
Define a purine
a nitrogenous base with a double-ring structure
110
list three phenotypes of an organism
-A behavioral response to certain condition
-an organisms observable characteristics
-which enzymes are being synthesized
111
Who presented the evidence that DNA was the genetic material rather than protein?
Alfred Hershey & Martha Chase
112
Who first demonstrated horizontal transmission of genetic information?
Fredrick Griffith
113
What did James Watson & Francis crick do?
published the first description of DNA as a double helix
114
Which researcher produced X-ray diffraction images of DNA that were critical to determining its structure but did not receive a Nobel prize with colleagues because it is not awarded posthumously?
Rosalind Franklin
115
One strand of DNA runs from 5′ to 3′ and the opposing strand runs 3′ to 5′, meaning that the strands are oriented in which way?
Antiparallel
116
Describe reannealing
the rejoining of two previously separated strands DNA
117
How do would you denature the proteins within DNA strands in a laboratory?
increasing the temperature
118
Describe vertical gene transfer
Transmission of genetic information from parent to offspring
119
List three differences between DNA & RNA
- DNA is usually double stranded and RNA is single stranded
-RNA contains uracil and DNA contains thymine
-RNA is usually less stable than DNA
120
What produces an RNA copy of a DNA molecule?
Transcription
121
in eukaryotes, where do rRNA synthesis and ribosome assembly occur?
in the nucleolus
122
What is located on the 5' end of a DNA strand?
a phosphate group
123
What happens to a pyrophosphate released during phosphodiester bond formation?
it is hydrolyzed to release energy
124
Who suggested that the DNA molecule may have three strands?
Linus Pauling
125
What enzyme helps prevent supercoiling?
Tpopisomerases
126
T/F all contact with a pathogen will result in infection
FALSE
127
Which virulence factor, produced by Staphylococcus aureus, allows the bacterium to be coated in fibrin that protects it from phagocytes?
Coagulase
128
Describe bacteremia
The blood contains actively dividing bacteria
129
Which surface molecules do helminths commonly express that protect them from the host immune system?
Glycans
130
What cells do enterotoxins target?
Intestinal cells
131
At what period of disease is when the patient begins to feel general signs and symptoms?
Prodromal period
132
Which toxin inhibits the release of glycine and GABA at the neuromuscular junction, thus preventing the relaxation of muscles?
Tetanus
133
Which period of disease is a patient most susceptible to developing a secondary infection?
Period of decline
134
T/F bacteria, fungi, and protozoa often use similar virulence factors and mechanisms of pathogenicity
True
135
T/F Facultative intracellular pathogens can reproduce both inside and outside host cell
True
136
In the A-B toxin, which subunit is necessary for making the initial attachment to the host cell?
The B subunit
137
What is the toxic component of entotoxin?
lipid A
138
Define pathogenicity
the ability of a microbial agent to cause disease
139
What is the CDC responsible for?
Monitors notifiable diseases
140
The components of a virus that is extended from the envelope for attachment is...
Spikes
141
Which of the following does a virus lack? select all that apply
-Ribosomes
-Metabolic processes
-nucleic acid
-glycoprotein
Ribosomes & Metabolic processes
142
Where is the envelope of a virus derived from?
The host's membrane structures
143
What do you call a nonenveloped virus?
a naked virus
144
What cycle leads to the destruction of the host cell?
The lysogenic cycle
145
What phase does a virus obtain its envelope?
during release
146
What is the name for the transfer of genetic information from one bacterium to another bacterium by a phage?
Transduction
147
Which of these infectious agents do not have nucleic acid?
Prions
148
Who is credited for first finding an antimicrobial agent?
Alex Fleming
149
T/F Isoniazid is an antimetabolite that can be used to treat mycobacterial infections
True
150
T/F The Kirby-Bauer disk diffusion assay can distinguish between bacteriostatic and bactericidal agents
False
151
Continued use of quinolones can lead to hallucinations, cardiac complications, and, potentially, anemia.
True
152
Alexander Fleming first observed a mold (now known as Penicillium notatum) that was able to inhibit which organism?
Staphylococcus
153
Which of the following was the first broad-spectrum antibiotic to be approved by the FDA?
chloramphenicol
154
Who is credited for first finding a naturally occurring antimicrobial agent?
Alexander Fleming
155
Which was the first antimicrobial agent discovered to treat syphilis?
compound 606
156
What removes the primers during DNA replication in bacteria?
DNA polymerase I
157
What medication targets DNA gyrase and topoisomerase IV?
Quinolones
158
DNA polymerase III adds DNA nucleotides in what direction?
In the 5' to 3' direction only
159
____ in humans is generally active in stem cells and germ cells
Telomerase
160
The steps of gene expression is known as...
Central dogma
161
Describe uracil and where it is found.
It is a nitrogenous base found in RNA only
162
During bacterial DNA replication, what holds open the replication bubble?
Single-strand binding proteins
163
Which researchers provided evidence that DNA replication was semiconservative?
Matthew Meselson & Franklin Stahl
164
