Midterm #2 (lectures 12-21) Flashcards
1
Q
What was Mendel’s primary contribution to genetics?
A
Documents patterns of heredity in pea plants
1
Q
Which experiment was the final confirmation that DNA is responsible for transformation, not protein?
A
Hershey and Chase experiment
2
Q
What was Griffith’s primary contribution to genetics?
A
“Transformation experiments” transform non-pathogenic bacteria strains to pathogenic
3
Q
What was Chargaff’s primary contribution to genetics?
A
Discovers that A = T and C = G
4
Q
What was Watson and Crick’s primary contribution to genetics?
A
Proposed the double helix structure of DNA
5
Q
What are the 4 components of the structure of DNA?
A
- Deoxynucleotides 5’-triphosphate
- Free hydroxyl group from ‘ end to the 3’ end
- Double helix
- Antiparallel, which is complimentary and reverse
6
Q
How can the structure of DNA be denatured?
A
By heat or other chemicals
7
Q
True of False: DNA provides structural function?
A
False
8
Q
DNA is organized into into a _____, which is a genetic element where carrying genes essential for cellular function
A
chromosome
9
Q
What is the differences between prokaryote chromosomes and eukaryote chromosome?
A
Prokaryote: generally circular
Eukaryote: almost all linear
10
Q
The chromosome is much _____ than the cell
A
bigger
11
Q
Because the chromosome is much bigger than the cell, how do bacteria/eukarya/archaea deal with this?
A
Bacteria: supercoil by topoisomerase
Eukarya: histone to wrap around proteins
Archaea: supercoil + histone
12
Q
What is extrachromosomal DNA?
A
Genes that are non-essential
13
Q
Where is extrachromosomal DNA found?
A
Plasmids, mitochondrion, and chloroplasts
14
Q
What is the central dogma?
A
DNA to RNA via transcription, and RNA to Protein via translation
15
Q
What is the information functional unit?
A
Gene, which is made up of nucleic acid sequence
16
Q
What are the 3 kinds of RNA?
A
Messenger RNA (mRNA)
Transfer RNA (tRNA)
Ribosomal RNA (rRNA)
17
Q
What are the 3 kinds of DNA replication?
A
- Semi-conservative replication: results in two DNA molecules with one original strand and one new strand.
- Conservative replication: results in one molecule that consists of both original DNA strands and another molecule that consists of two new strands
- Dispersive replication: results in two DNA molecules where each individual strand is a patchwork of original and new DNA
18
Q
Which of the 3 DNA replication models is correct?
A
Semi-conservative
19
Q
What is the function of DNA polymerase I?
A
Removes RNA primer and replaces it with newly synthesized DNA
20
Q
What is the function of DNA polymerase II?
A
Main enzyme that adds nucleotides in the 5’ to 3’ direction
21
Q
What is the function of helicase?
A
Opens the DNA helix by breaking hydrogen bonds between the nitrogenous bases?
22
Q
What is the function of ligase?
A
Seals the gaps between the Okazaki fragments on the lagging strand to crease one continuous DNA strand
23
Q
What is the function of primase?
A
Synthesizes RNA primers needed to start replication
24
What is the function of single-stranded binding proteins?
Bind to single-stranded DNA to prevent hydrogen bonding between DNA strands, reforming double-stranded DNA
25
What is the function of topoisomerase II (DNA gyrase)?
Relaxes supercoiled chromosome to make DNA more accessible for the initiation of replication; helps relieve the stress on DNA when unwinding, by causing breaks and then resealing the DNA
26
What is the function of topoisomerase IV?
Introduced single-stranded break into concatenated chromosomes to release them from each other, and then reseals the DNA
27
What is the structure and function of mRNA?
Structure: short, unstable, single-stranded
Function: serves as an intermediary between DNA and protein
28
What is the structure and function of rRNA?
Structure: longer, stable RNA molecules
Function: ensures the proper alignment of mRNA and ribosome during protein synthesis
29
What is the structure and function of tRNA?
Structure: short, stable RNA
Function: carries the correct amino acid to the site of protein synthesis in the ribosome
30
What is a sigma factor?
A protein needed for initiation of transcription in bacteria, enables specific binding of RNA polymerase to gene promoters
31
What are promoter regions?
Where DNA polymerase initiates the process
32
Th stronger the match, the stronger the sigma factor, the stronger the _______ will be
transcription
33
What are alternative sigma factors?
Response to different environments/stresses/signals
34
The more sigma factors you have, the more you can respond to the environment by modifying the sigma factor sequence, you are changing how ?
genes are expressed
35
What is an Open Reading Frame (ORF)?
Spans of DNA sequence between the start and stop codons
36
What is the term polycistronic mean?
describes the situation in which two or more separate proteins are encoded on a single molecule of messenger RNA (mRNA). In prokaryotes, polycistronic expression is common
37
What is an operon?
A cluster of genes that are transcribed together to give a single messenger RNA (mRNA) molecule, which therefore encodes multiple proteins
38
What are the 2 different ways of Termination of a specific sequence?
1. Stem loop: GC-rich sequence, inverted loop, RNA pol pauses
2. Rho-dependent: termination site, Rho cause RNA release
39
Compare the promoters in bacteria vs archaea vs eukarya
Bacteria: sigma box, -10 and -35 box
Archaea: TATA box
Eukarya: Similar to archaea
40
Compare the termination in bacteria vs archaea vs eukarya
Bacteria: stem loop and Rho
Archaea: Stem loop but no Rho
Eukarya: no loop, several factors
41
Compare the processing in bacteria vs archaea vs eukarya
Bacteria: absent
Archaea: some processing
Eukarya: exons and introns
42
Compare the cistonic in bacteria vs archaea vs eukarya
Bacteria: polycistronic
Archaea: polycistronic
Eukarya: monocistronic
43
Compare the chromosomes in bacteria vs archaea vs eukarya
Bacteria: single, circular; multiple linear, haploid, lack histone
Archaea: single, circular; multiple, histone
Eukarya: multiple, linear; haploid, multi, histone
44
Compare the replication in bacteria vs archaea vs eukarya
Bacteria: single origin, replisome (gyrase)
Archaea: single, multiple, machinery similar to eukarya + gyrase
Eukarya: no gyrase
45
Compare the transcription in bacteria vs archaea vs eukarya
Bacteria: protein + structure, unique machinery
Archaea: protein + structure, eukarya-like machinery
Eukarya: protein-termination, unique machinery
46
What is the Wobble position?
3rd nucleic acid on the codon, can change but it is still the same amino acid
47
What is codon bias?
One bacteria may prefer one sequence compared to another, even if they give the same amino acid
48
To get a functional protein, you need ?
1. Protein folding (spontaneous, requires assistance, misfolding)
2. Chaperones (energy dependent process, folding and refolding, add cofactors, help secretion)
49
Describe Type I gram-negative secretion system
ABC transporter
One step: cytoplasm to outside
50
Describe Type II gram-negative secretion system
Sec and Tat dependent
Two step: secrete from periplasm
51
Describe Type V gram-negative secretion system
Autotransporter
Sec and Tat dependent
Two step: secrete from periplasm
52
Describe Type III gram-negative secretion system
One step
Syringe-like
Bacterial pathogens
Inject proteins into eukaryotic cells
53
Describe Type IV gram-negative secretion system
One step
Pilus-like
Transfer DNA
54
Describe Type VI gram-negative secretion system
One step
Spear-like
Bacteriophage tail
Pierce the membrane
Bacteria-bacteria competition
55
What is genetic regulation?
Control mRNA production through transcription
56
What is post-transcription?
Control mRNA stability, and control translation
57
What is post-translation?
Control protein activity
58
What is the difference between genes that are constitutively expressed and genes that are expressed when needed?
Constitutively: essential function
Expressed when needed: under specific condition
59
What is the main function of effectors?
Change binding affinity
60
Operon vs regulon
Operon: 1 promoter with many genes, polycistronic
Regulon: 1 regulator, many promoters. Disperse through the chromosome
61
What are regulatory RNAs?
RNA that are not translated, small RNA (sRNA)
62
What is the intergenic region?
Low degree of complementary, needs a helper (protein)
63
What are the 3 different mechanisms of RNA-based regulation?
1. Affect mRNA stability (protect RNA from degradation, target RNA for degradation)
2. Block RBD (block translation)
3. Change the secondary structure
64
What is attenuation in terms of RNA-based regulation?
A secondary structure that in the mRNA that will allow translation or not based on the level and speed of translation
65
What are riboswitches in terms of RNA-based regulation?
Secondary structures found in the RNA strand that will allow for transcription or translation to proceed. But they need a cofactor to bind to that structure or not to bind.
66
What are the 2 ways to remove a protein?
Degradation and sequestration
67
What are the 2 parts of Two-component regulatory systems?
Sensor histidine kinase
Response regulator
68
How do two-component regulatory systems?
Stimuli induces autophosphorylation at the histidine residue. Transfer of phosphate to regulator, and has a feedback loop
69
What is Quorum Sensing?
a process of cell–cell communication that allows bacteria to share information about cell density and adjust gene expression accordingly
70
How do bacteria acquire genetic diversity?
Vertical: new mutation
Horizontal: gene expression and acquisition, and selfish genetic elements
71
What are mutations?
Changes in the nucleotide sequence
72
What is a wild-type mutation?
Parental, isolated from nature
73
What is a mutant?
Carries change, has a different genotype
74
How do you increase the mutation rate?
Stresses and mutagens, which are naturally found in the environment
75
How do we determine mutagenic potential?
The Ames test: ability of a chemical to induce a revertant in an auxotroph. The higher the number of colonies, the higher the potential
76
What is a point mutation?
Substitution, deletion or insertion of a single base pair
77
What is a silent mutation?
Substitution of a 3rd base of codon. There is no change in amino acid
78
What is a missense mutation?
Substitution of 1st and 2nd base of codon. Amino acid change in protein
79
What is a nonsense mutation?
Amino acid change to a stop codon. Causes an incomplete/truncated protein
80
What is a frameshift mutation?
Single nucleotide inserted or removed, and causes a shift in the reading frame
81
What is reversion?
A second mutation that can reverse the effect of a mutation
82
What is a revertant?
The phenotype is restored to the wild-type
83
What is a true revertant?
Genotype is restored to the wild-type
84
What is transformation?
Genetic transfer of free DNA to competent cells that are able to take said DNA
85
What is conjugation?
Genetic transfer requiring cell-cell contact. Plasmid encoded
86
What is transduction?
Phages pick up host DNA and transfer into a new host
87
What are the 2 kinds of transduction?
1. Generalized: lytic phage/defective phage
2. Specialized: temperate phage
88
What is phage conversion?
Alteration of phenotype by prophages. Harmless bacteria can become pathogens
89
What are 4 ways that prokaryotes defend themselves?
Mutation in receptors
Restriction enzymes
Phage exclusion
Programmed cell death
90
What is CRISPR?
Cluster Regularly Interspaced Short Palindromic Repeats
Seek and destroy foreign nucleic acid
91
What is genetic engineering?
Using in vitro techniques to alter genetic material in the lab
92
What is a vector?
DNA molecule (often plasmid or virus) that is used as a vehicle to carry a particular DNA segment into a host cell as part of a cloning or recombinant DNA technique
93
What is heterologous?
Expressing a gene in a different host
94
What is a thermocycler?
Automated PCR machine
95
What is the proper order in the steps in PCR amplification:
1. Synthetic piece of DNA flanking sequence of interest to the reaction mixture is added
2. Heat and cool -repeat many similar cycles
3. Repeat 20-30x
4. DNA to be amplified is denatured by heating
5. Add DNA polymerase which extends primers using DNA
4, 1, 5, 2, 3
96
PCR requires DNA ______ and artificial oligonucleotide _____ made of DNA and uses ______ DNA polymerase
polymerase, primers, thermostable
97
Reverse Transcription PCR makes DNA from an mRNA _____, detects gene expression or produced intron-free eukaryotic gene for expression in bacteria, uses the enzyme reverse _______ to convert RNA into complementary DNA
template, transcriptase
98
Agarose gel electrophoresis separates DNA molecules based on ___ and _____, nucleic acids migrate through the gel towards the ______ electrode, and ____molecules move _____ than large ones
size , charge, positive, small, faster
99
Agarose gels can be stained with ? and DNA is visualized under ___ light
ethidium bromide, UV
100
The same DNA cut with different _______ enzymes
will have different banding patterns on an agarose gel
restriction
101
Nucleic acid hybridization is used to detect a certain nucleic acid sequence, from ___ different sources to give a hybrid, occurs usually with ______/_______ products.
2, colored, fluorescent
102
What is a nucleic acid probe?
a single-stranded DNA or RNA fragment of known structure or function and is used to detect a target sequence of DNA in a sample
103
How does a nucleic acid probe work?
DNA probes will bind to the gene of interest if it is present in the sample
104
What is a southern blot?
Hybridization procedure where DNA is in the gel and probe is RNA or DNA
105
What is a northern blot?
RNA is in the gel and the Probe is DNA or RNA
106
What is FISH?
Fluorescent In Situ Hybridization, uses a fluorescent probe attached to oligonucleotide
107
What is synthesized DNA used for?
For primers and probes, and site-directed mutagenesis
108
What is cloning?
Movement of a gene from original source to small and manipulable genetic element (vector)
109
What are the 2 main enzymes used for cloning?
1. Restriction endonucleases
2. DNA ligase: catalyzes the joining of two strands of DNA between the 5' phosphate and 3' OH
110
What are two other enzymes used for cloning?
Reverse transcriptase: converts RNA into DNA
DNA polymerase: Mostly used for 5’to 3' polymerizing activity. May also have 3’to 5' and 5’ to 3' exonuclease activity
111
What are restriction endonucleases?
Recognize specific DNA sequences and cut DNA, widespread among bacteria but rare in eukaryotes
112
What is the main function of Type II restriction endonucleases?
Cleave DNA within recognition sequence; most useful for specific DNA manipulation. Recognize inverted repeat sequences (palindromes)
113
Molecules with complementary sticky ends can easily ____ or form
hydrogen bonds between complementary bases. Annealing step allows ______ of the single stranded overhangs
anneal, hybridization
114
_____ by DNA ligase can rejoin the two sugar-phosphate backbones of DNA through covalent binding
Ligation
115
Each restriction enzyme is partnered with a corresponding modification enzyme that shares the _____ recognition sequence
SAME
116
What is the overall 7 steps in gene cloning:
1. Allows insertion of foreign DNA at a restriction site on a cloning vector by restriction enzymes/endonucleases
2. Isolation and fragmentation of source DNA
3. Expression of cloned gene and selection of gene product
4. Insertion of DNA fragment into cloning vector
5. Gene to be cloned can be amplified by polymerase chain reaction, synthesized by reverse transcriptase, or synthetic DNA made in vitro
6. Introduction of cloned DNA into host organism
7. Small, independently replicating genetic elements than can carry and replicate cloned DNA
2, 5, 4, 7, 1, 6, 3
117
What is recombineering?
Allows foreign DNA to be inserted into
vectors/chromosome
118
Biggest limitation of cloning is ?
modifications can only be
made at restriction enzyme sites
119
Why plasmids as cloning vectors?
Small size; easy to isolate DNA, Independent origin of replication, Multiple copy number; get multiple copies of cloned gene per cell
120
What is Blue-White screening?
Bacteria with cloning vector which may or may not
contain “insert” DNA. Blue colonies do not have vector with foreign DNA inserted, white colonies have foreign DNA inserted
121
Plasmids specifically for cloning DNA products made by ___ in PCR, adds template-independent adenosine to 3'-end
Taq
122
Linearized vectors containing overhanging thymidine allow _____ ____ and ____
base paring, ligation
123
What are shuttle vectors?
It can propagate in two different host species. Therefore, DNA inserted into a shuttle vector can be tested or manipulated in two different cell types.
124
If cells express the foreign gene expression might be detected using: ?
Antibodies, usually fluorescently labelled
125
Ideal hosts should be: ?
Capable of rapid growth in inexpensive medium
Nonpathogenic
Capable of incorporating DNA
Genetically stable in culture
Equipped with appropriate enzymes
126
What are expression vectors?
Allow experimenter to control the expression of cloned genes
127
Obstacles in ways to express foreign genes include need for bacterial _____, _____ must be removed, codon usage/bias, post-translational ______
promoter, introns, modifications
128
Recombinant proteins may cause problems like..?
Degradation by proteases, toxicity, insoluble inclusions
129
What is site-directed mutagenesis?
Performed in viro and introduced mutations at a precise location, and can be used to assess the activity of a specific amino acid in a protein
130
What are DNA cassettes/cartridges?
Synthetic fragments that can make more than a few base pair changes or replace sections of a gene via cassette mutagenesis
131
What is gene disruption?
Inserts cassettes in middle of a gene, disrupting coding sequence
132
What is a knockout mutation?
Loss of function if a gene in which cassette is inserted
133
Gene ______ determine whether a gene is essential
knockouts
134
What is a reporter gene?
Encodes protein, easy to detect and assay
135
What are operon fusions?
Coding sequence with its own translational start site and signals are fused to transcriptional signals of another gene
136
What are protein fusions?
Genes encoding two proteins are fused to share the same transcriptional and translational start and stop and yield one hybrid polypeptide
137
What is a generation?
Refers to a successive major changes in sequencing technology
138
The first generation of DNA sequencing used the ______ method
Sanger
139
The Sanger method required that ?
Labeled dideoxynucleotides were added to a reaction so that the elongation of new DNA chains would terminate when the dideoxynucleotides were incorporated
140
Second generation sequencing used similar chemistry, but ______ the reactions and improved ______ methods and computation so that more sequence information could be collected very rapidly
miniaturized, detection
141
Third generation sequencing improved detection such that _____ molecules could be detected, thus even more _____ could be generated
single, sequence
142
________ (second-generation) uses luciferase to detect incorporation of dNTPs
Pyrosequencing
143
Describe 3rd Generation Nanopore Minion
When DNA molecules pass through or near the nanopore, there will be a change in the magnitude of the current in the nanopore, which is measured by a sensor
144
What is annotation?
Converting raw sequence data into a list of genes present in the genome
145
What are hypothetical proteins?
Uncharacterized ORFs; proteins that likely exist but whose function is currently unknown
146
What is metagenomics?
Analyzes pooled DNA or RNA from environmental sample containing organisms which have not been isolated/identified
147
What is the metagenome?
Total gene content of microbial community
148
What is transcriptomics?
The study of the complete set of RNA transcripts that are produced from genomic DNA in cells or tissues
149
What is the transcriptome?
The entire complement of RNA produced under a given set of growth conditions
150
What are microarrays?
Small solid-state supports to which gene or portions of genes are fixed and arrayed spatially in a known pattern
151
DNA segments/fragments on arrays are ______ with mRNA from cells grown under specific conditions and analyzed to determine
patterns of gene expression
hybridized
152
Arrays are large and dense enough that the transcription pattern of an ____ genome can be analyzed
entire
153
What kind of information can be derived from microarrays?
Global gene expression
Expression of specific groups of genes under different conditions
Expression of genes with unknown function, can yield clues to possible roles
Comparison of gene content in closely related organisms
Identification of specific organisms
154
What is proteomics?
Study of the entire protein complement of a cell
155
Proteins with >__% sequence similarity typically have similar functions; proteins with >__% sequence similarity almost certainly have similar functions
50, 70
156
What are protein domains?
Distinct structural modules within proteins and have characteristic functions
157
What are Interactomes?
Complete set of interactions among macromolecules, and the data expressed in the form of network diagrams
158
What is metabolomics?
Study of the set of metabolites present within an organism, cell, or tissue
159
What is the metabolome?
The complete set of metabolic intermediates and other small molecules produced in an organism
160
What is systems biology?
Integration of different fields of "omics" research
161
What is genetic drift?
The change in frequency of an existing gene variant in the population due to random chance, may cause gene variants to disappear completely and thereby reduce genetic variation
162
Duplication and deletion has major evolutionary roles: ?
Govern genome size and content
Must classify genes based on shared ancestry for comparison
163
What are Orthologs?
Genes which evolved from a common ancestral gene by speciation that usually have retained a similar function in different species
164
What are Paralogs?
Genes related by duplication within the genome and often they acquire a new function
165
What is a homolog?
Gene inherited in two species from a common ancestor. While homologous genes can be similar in sequence, similar sequences are not necessarily homologous
166
How do duplication mutations increase
microbial fitness?
A duplication mutation creates a redundant copy of a gene sequence in the genome. The original gene copy retains its function, making it possible for the second copy to accumulate mutations freely without a loss of gene function in the cell so evolution can “experiment” with one copy of the gene
167
What is horizontal gene transfer?
The transfer of genetic information between cells, as opposed to vertical inheritance from parental organism(s)
168
What are the 3 mechanisms of horizontal gene transfer?
Transformation, transduction, and conjugation
169
______ counters effect of deletions, preserving genes that benefit fitness
Selection
170
What is the mobilome?
All kinds of transferrable elements, which includes plasmids, bacteriophage, transposons, integrations, etc
171
Horizontally transferred genes typically do/do not encode core metabolic functions?
do not
172
Comparative genomic analyses show entire genetic pathways (chromosomal/genomic islands) can be acquired via ?
horizontal gene transfer
173
What is the core genome?
Consists of genome of genes shared by all the strains studied and probably encode functions related to the basic biology
174
What is the pan-genome?
The sum of the core genome and the dispensable genome
175
What is phylogeny?
The relationship of all organisms on the earth and assumes a common ancestor. It encompasses the genetic and genomic diversity of evolutionary lineages. Can be defined on the basis of genes or organisms
176
More than 90 percent of characterized genera and
species come from four phyla: ?
Proteobacteria
Actinobacteria
Firmicutes
Bacteroidetes
177
80+ phyla can be distinguished based on ____ ribosomal RNA
16S
178
Place these categories into the proper order:
1. Phylum
2. Genus
3. Domain
4. Order
5. Class
6. Species
7. Family
3, 1, 5, 4, 7, 2, 6
179
_______ largest and most metabolically diverse phylum
Proteobacteria
180
______ make up the majority of known medically, industrially, and agriculturally significant bacteria
Proteobacteria
181
_______ are all gram-negative
Proteobacteria
182
________ have diverse energy generation mechanisms, diverse relationships with oxygen, and a variety of morphologies
Proteobacteria
183
Proteobacteria is divided into six classes: ?
Alpha-, Beta-, Delta-, Gamma-, Epsilon-, Zeta-
184
________ most are obligate aerobes or facultative aerobes, and many are oligotrophic
Alphaproteobacteria
185
Describe Rickettsia
Alphaproteobacteria
Typhus; Rocky Mountain spotted fever
Ticks, fleas, lice, and mites
Unable to synthesize some metabolites, cell walls, host cell bursts and frees cells
186
______ is the third-largest class of Proteobacteria and has much functional diversity
Betaproteobacteria
187
Describe Neisseriales
Betaproteobacteria
Diverse chemoorganotrophs
Found from moist areas/oral cavity
Some pathogenic
Always cocci
188
________ is the largest, most diverse class of Proteobacteria
Gammaproteobacteria
189
_______ have diverse metabolic and ecological characteristics, known human pathogens, phototrophs, chemoorganotrophs,
chemolithotrophs, respiratory or fermentative metabolisms
Gammaproteobacteria
190
Describe Enterobacteriales
Gammaproteobacteria
Facultative aerobic, gram-negative, nonsporulating
Oxidase -, catalase +
Two fermentation patterns
191
What are the 2 fermentation patterns in enteric bacteria?
1. Mixed-acid fermentation: acetic, lactic, and succinic acid formed in significant amounts; ethanol, CO2, and H2
2. 2,3-butanediol fermentation: Butanediol,
ethanol, more CO2 than H2, are main products; smaller amounts of acids formed
192
What are the 4 types of Mixed-Acid fermenters?
Escherichia, Salmonella, Shigella, Proteus
193
Describe Escherichia
Synthesize vitamins
Facultative aerobe that helps make large intestine anoxic
Some strains are pathogenic
194
Describe Salmonella
Almost always pathogenic
Causes typhoid fever and gastroenteritis
195
Describe Shigella
Typically pathogenic
Causes bacillary dysentery
196
Describe Proteus
Genus containing highly motile cells
Frequent cause of urinary tract infections
Capable or swarming
197
What are the 3 types of butanediol fermenters?
Enterobacter aerogenes, klebsiella, serratia
198
Describe Enterobacter aerogenes
Gammaproteobacteria
Found in water, sewage, and intestinal tract
May cause urinary tract infection
199
Describe Klebsiella
Gammaproteobacteria
Occasionally causes pneumonia
Most strains fix nitrogen
200
Describe Serratia
Gammaproteobacteria
Forms red pyrrole-containing pigments called prodigiosins
May cause infection
Found in water, soil, and intestinal tracts
201
Describe Pseudomonadales
Gammaproteobacteria
High antibiotic resistance
Aerobic respiratory chemoorganotrophs
Oxidase -, catalase +
202
Describe Vibrionales
Gammaproteobacteria
Facultatively aerobic rods and curved rods that ferment
Cholera causes cholera in humans
203
Describe Firmicutes
Endospore formers, lactic acid bacteria, others
Low G+C gram-positive bacteria
204
Describe Tenericutes
Lack a cell wall, gram-positive
205
Describe Actinobacteria
High G+C gram-positive bacteria
206
Describe Lactobacillales
Firmicutes
Lactobacillus, streptococcus
Lactic acid bacteria: fermented
Widely used in food production
Aerotolerant anaerobes
207
What is homofermentative?
Produce only lactic acid
208
What is heterofermentative?
Produce ethanol, CO2, and lactate
209
What are the 2 groups of streptococci?
Pyogenes and Viridans, and they are blood agar hemolysis diagnostic
210
Describe Firmicutes: Nonsporulating Bacillales Clostridiales
Staphylococcus
Catalase +, gram-positive
Resistant to reduced water potential
Antibiotic resistant
211
Describe Firmicutes: Sporulating Bacillales and Clostridiales
All endospore-forming bacteria are Bacillales or Clostridiales
Generally found in soils
Pathogenic species are saprophytic
212
What does saccarolytic mean?
Ferment sugars
213
What does proteolytic mean?
Ferment amino acids or amino acid pairs
214
Describe Clostridium
Lacks a respiratory chai and obtains ATP by substrate level phosphorylation
Some are pathogenic, causing botulism, tetanus, gangrene, and gastroenteritis
215
What are the 3 different methods of control?
Physical, mechanical removal, and chemical
216
What is sterilization?
For inanimate items, completely eliminate all vegetative cells, endospores, and viruses
217
What is disinfection?
For inanimate items, reduces or destroys microbial load using heat or chemicals
218
What is sanitization?
For inanimate objects, reduces microbial load to a safe public health level using heat or chemicals
219
What is antisepsis?
For living tissues, reduces microbial load using an antimicrobial chemicals
220
What is degerming?
For living tissues, reduces microbial load using scrubbing and mild chemicals
221
What are the 2 main physical methods of control?
Heat and radiation
222
What is boiling?
Denatures proteins and alters membranes
223
What is autoclaving?
Sterilizes at 121°C for 15 mins or more
224
What is pasteurization?
HTST: heated at 72°C for 15s
UHT: heated at 13°8°C for +2s
225
Which 6 physical methods of control reduce the population by killing?
Boiling, dry-heat oven, incineration, autoclave, pasteurization, high-pressure processing
226
Which 6 physical methods of control control growth?
Refrigeration, freezing, Hyperbaric oxygen therapy, simple desiccation, reduce water activity, lyophilization
227
What is the main example of mechanical removal controls?
Filters
228
What are the 2 main chemical methods of control?
Gases and liquids
229
What are the 2 divisions of gases?
Sterilization and disinfection
230
What are the 2 divisions of liquid chemical controls?
Living and non-living
231
What is bacteriostatic?
Stops growth, but does not kill
232
What is bactericidal?
Kills bacteria
233
What is bacteriolytic?
Lyses cells
234
What is fungistatic/cidal?
Targets fungi
235
What is viricistatic/dal?
Targets viruses
236
What is sporocidal?
Kills spores
237
Selective toxicity for chemotherapy is _____ for bacteria, _____ for virus and very ____ for eukaryotic pathogen
easier, harder, hard
