Exam Ii Microbiology

Front 1

Genes?

Back 1

The information containing region of the chromosome.

Front 2

Genome?

Back 2

The total complement of genes found in a cell

Front 3

Genotype?

Back 3

Genetic composition of an organism

Front 4

Phenotype?

Back 4

When an organism expresses observable characteristics

Front 5

Transcription?

Back 5

A process by which the genetic information contained in DNA is copied into mRNA

Front 6

Translation?

Back 6

The process by which mRNA relays information to synthesize protein molecules.

Front 7

Polycistronic?

Back 7

Having more than one cistron or gene.

Front 8

True or False. A polycistronic mRNA molecule codes for only one protein.

Back 8

False. A polycistronic mRNA molecules encode for several proteins.

Front 9

Are prokaryotic or eukaryotic mRNA more likely to be polycistronic (having more than one cistron or gene)?

Back 9

Prokaryotic mRNA

Front 10

How many bases comprise of one codon?

Back 10

There are four bases that are arranged into three letter words called codons

Front 11

How are codons arranged?

Back 11

In triplets

Front 12

How many different codons represent the genetic code.

Back 12

There are four different bases arranged in triplets, 64 total.

Front 13

How many of the 64 codons actually code for amino acids?

Back 13

Only 61 code for amino acids.

Front 14

How many of the 64 codons do not code for amino acids? What are they called specifically?

Back 14

3 codons do not code for amino acids. These include the triplets UAA, UAG, UGA. They are called nonsense or termination codons.

Front 15

What do nonsense codons do?

Back 15

They signal the termination of protein synthesis (Translation).

Front 16

True or False. One amino acid is represented by one codon.

Back 16

False. Many amino acids are represented by more than one codon.

Front 17

Which position of the three letter triplet is considered the most degenerate?

Back 17

The third position of the codon triplet is considered the most degenerate.

Front 18

Which position(s) of the codon triplet is the same for alanine?

Back 18

Alanine is encoded by GCU, GCC, GCA, and GCG. The first 2 positions are the same while the third position changes (is degenerate).

Front 19

Which amino acid(s) is represented by only one codon?

Back 19

Only tryptophan and methionine are represented by only one codon.

Front 20

What are the stop codons?

Back 20

UAA, UAG, UGA

Front 21

AUG represents what type of codon? Which amino acid does it code for?

Back 21

AUG codes for methionine and is a start codon.

Front 22

UGG is the code for which amino acid?

Back 22

Tryptophan.

Front 23

Who determined the 3-D structure of the DNA molecule?

Back 23

Watson and Crick

Front 24

Watson and Crick

Back 24

Used x-ray crystalography to determine the structure of DNA.

Front 25

Griffith experiments demonstrated what.

Back 25

bacterial transformation, used emzymes

Front 26

Meselson and Stahl determined?

Back 26

DNA replication is semi-conservative.

Front 27

Theta replication ?

Back 27

Circular DNA molecule with two replication forks

Front 28

Initiator proteins

Back 28

Recognize and bind to a specific DNA sequence of about 300 bases at the origin of replication.

Front 29

unwinds short sections of the helix in advance of the replication fork

Back 29

DNA helicase

Front 30

Assists in unwinding and joining the DNA

Back 30

DNA topoisomeraeses

Front 31

Okazaki fragments are only formed in which strand of a DNA molecule?

Back 31

The lagging strand.

Front 32

Which DNA polymerase is associated with E. coli?

Back 32

DNA polymerase I, II, III

Front 33

Enzymes that catalyze DNA synthesis add nucleotides in which direction?

Back 33

Nucleotides are added to the 3'-OH end of the DNA molecule.

Front 34

Which daughter strand are okazaki fragments formed in?

Back 34

The lagging strand

Front 35

How can one differentiate between a "lagging" and "leading" strand?

Back 35

In DNA synthesis, the "lagging" strand is discontinuous and contains okazaki fragments while the "leading" strand is continous.

Front 36

DNA is READ in which direction? BUILT?

Back 36

DNA is read in the 3'-OH to 5'-PO4 direction and is built in the 5'-PO4 to 3'-OH direction

Front 37

In E. coli, which DNA polymerase catalyzes the addition of mononucleotides? ON which end of a DNA strand?

Back 37

Polymerase I, II, and III catalyze the addition of mononucleotides to the 3'-OH end of a growing polynucleotide.

Front 38

Which DNA polymerase is the komberg enzyme?

Back 38

DNA polymerase I.

Front 39

What mechanism is the komberg enzyme involve with? What does this mechanism facilitate?

Back 39

The komberg enzyme (DNA polymerase I) facilitates the excision-repair mechanism which is involved in DNA repair of UV damage.

Front 40

What does DNA polymerase require in which to add mononucleotides on to a growing DNA strand?

Back 40

DNA polymerase can only add nucleotides to a pre-existing 3'-OH group, and therefore needs a primer at which to add the first nucleotide.

Front 41

OriC is known as what?

Back 41

The origin of replication

Front 42

Ter is known as what?

Back 42

DNA replication terminus site-binding protein

Front 43

Dna replication used by bacterial viruses.

Back 43

The rolling circle mechanism

Front 44

The rolling circle mechanism is used by which type of organism(s) during DNA replication.

Back 44

The rolling circle mechanism is used for DNA replication in bacterial viruses, bacteriophages, and during DNA replication in conjugation.

Front 45

During conjugation, this type of DNA replication is used.

Back 45

Rolling circle mechanism

Front 46

This type of nucleic acid replaces thymine with uracil.

Back 46

Ribonucleic Acid (RNA)

Front 47

Which nucleic acid usually exists in a single stranded form?

Back 47

RNA

Front 48

Which sugar is RNA composed of? DNA?

Back 48

RNA is composed of ribose sugars, DNA is composed of deoxyribose sugars.

Front 49

List the 3 forms of RNA.

Back 49

mRNA, rRNA, tRNA

Front 50

Which form(s) of RNA is transcribed from a DNA template? Which polymerase(s) does this?

Back 50

All 3 forms of RNA are transcribed from a DNA template. This done by DNA-dependent RNA polymerase.

Front 51

True or False. The RNA polymerase is a multi-subunit enzyme.

Back 51

True.

Front 52

Subunit(s) that make up RNA polymerase.

Back 52

There are 4 subunits that comprise the complete RNA polymerase enzyme. Alpha, Beta, Beta', and Sigma.

Front 53

This subunit is the initiation factor of RNA polymerase.

Back 53

Sigma

Front 54

Consider RNA polymerase: Which subunit is required for promoter binding. Does this subunit dissociate at any point during polymerization?

Back 54

The sigma subunit is required for promoter binding, once polymerization begins, this subunit dissociates from the core enzyme.

Front 55

Polymerization?

Back 55

Any process in which relatively small molecules (monomers) combine chemically to produce a very large chainlike structure.

Front 56

One of the largest enzymes known.

Back 56

RNA polymerase

Front 57

This enzyme is a point of difference between bacteria, archaea, and eukarya

Back 57

RNA polymerase

Front 58

Bacteria has how many RNA polymerases. How many subunits?

Back 58

1, 6 subunits

Front 59

Archaea has how many RNA polymerases. How many subunits?

Back 59

several types, 8-12 subunits

Front 60

Eukarya has how many RNA polymerases. How many subunits?

Back 60

several types, 12-14 subunits

Front 61

Which phylogenic group has RNA polymerase composed of the most subunits.

Back 61

Eukarya, RNA polymerase has 12-14 subunits

Front 62

Which RNA type is the most varied?

Back 62

mRNA

Front 63

Approximate life span of mRNA in a bacterial cell.

Back 63

Few minutes

Front 64

This type of RNA carries genetic material from the DNA template to the ribosomes

Back 64

mRNA

Front 65

The entire or functionally complete enzyme

Back 65

Haloenzyme

Front 66

Polycistronic mRNA are common in which organism(s).

Back 66

prokarytoes (bacteria)

Front 67

Carries the information of several genes, which are translated into several proteins

Back 67

polycistronic mRNA

Front 68

Polycistronic mRNA

Back 68

mRNA that commonly contains information for the amino acid sequence for several different polypeptide chains.

Front 69

A single linear chain of amino acids bonded together by peptide bonds.

Back 69

Polypeptide

Front 70

Polypeptide

Back 70

A single linear chain of amino acids bonded together by peptide bonds.

Front 71

In E. coli, the 10 enzymes neede to synthesize histidine are encoded in 1 mRNA molecule. This is an example of?

Back 71

Polycistronic mRNA

Front 72

True or False. All base sequences in an mRNA molecule is translated into the amino acid sequence for polypeptides.

Back 72

False. Not all bases are translated.

Front 73

Consider translation: What is the region known as the leader?

Back 73

Translation of mRNA rarely starts exactly at one end of the mRNA molecule and proceeding to the other other. Instead, it may begin 100's of nucleotides in from the 5'-PO4 terminus. This UNTRANSLATED region is called the leader.

Front 74

Separates the coding sequence in polycistronic mRNA, is usually about 10 bases long

Back 74

spacer sequence

Front 75

What does the coding sequence of mRNA determine?

Back 75

Determines the amino acid sequence in the protein that is being translated.

Front 76

In bacteria, the intact ribosomal particle is called.

Back 76

A 70S ribosome

Front 77

Consider the 70S ribosome which is comprised of a large and small subunit: How is the intact ribosomal particle broken down within each subunit?

Back 77

The large 50S ribosomal subunit contains two rRNA species (the 5S and 23S rRNAs). The small 30S ribosomal subunit contains the 16S rRNA.

Front 78

Consider translation: What is the region known as the leader?

Back 78

Translation of mRNA rarely starts exactly at one end of the mRNA molecule and proceeding to the other other. Instead, it may begin 100's of nucleotides in from the 5'-PO4 terminus. This UNTRANSLATED region is called the leader.

Front 79

Separates the coding sequence in polycistronic mRNA, is usually about 10 bases long

Back 79

spacer sequence

Front 80

What does the coding sequence of mRNA determine?

Back 80

Determines the amino acid sequence in the protein that is being translated.

Front 81

In bacteria, the intact ribosomal particle is called.

Back 81

A 70S ribosome

Front 82

Consider the 70S ribosome which is comprised of a large and small subunit: How is the intact ribosomal particle broken down within each subunit?

Back 82

The large 50S ribosomal subunit contains two rRNA species (the 5S and 23S rRNAs). The small 30S ribosomal subunit contains the 16S rRNA.

Front 83

Consider the 80S ribosome which is comprised of a large and small subunit: How is the intact ribosomal particle broken down within each subunit?

Back 83

The large 60S ribosomal subunit contains three rRNA species (the 5S, 5.8S, and 28S rRNAs). The small 40S ribosomal subunit contains the 18S rRNA.

Front 84

In eukaryotes, the intact ribosomal particle is called.

Back 84

The 80S ribosome

Front 85

Consider prokaryotic rRNA: How is the intact ribosomal particle broken down within the large subunit?

Back 85

The large 50S ribosomal subunit contains two rRNA species (the 5S and 23S rRNAs).

Front 86

Consider prokaryotic rRNA: How is the intact ribosomal particle broken down within the small subunit?

Back 86

A small 30S ribosomal subunit contains the 16S rRNA.

Front 87

Consider eukaryotic rRNA: How is the intact ribosomal particle broken down within the large subunit?

Back 87

The large 60S ribosomal subunit contains three rRNA species (the 5S, 5.8S, and 28S rRNAs).

Front 88

Consider the 80S ribosome which is comprised of a large and small subunit: How is the intact ribosomal particle broken down within each subunit?

Back 88

The large 60S ribosomal subunit contains three rRNA species (the 5S, 5.8S, and 28S rRNAs). The small 40S ribosomal subunit contains the 18S rRNA.

Front 89

In eukaryotes, the intact ribosomal particle is called.

Back 89

The 80S ribosome

Front 90

Consider prokaryotic rRNA: How is the intact ribosomal particle broken down within the large subunit?

Back 90

The large 50S ribosomal subunit contains two rRNA species (the 5S and 23S rRNAs).

Front 91

Consider prokaryotic rRNA: How is the intact ribosomal particle broken down within the small subunit?

Back 91

A small 30S ribosomal subunit contains the 16S rRNA.

Front 92

Consider eukaryotic rRNA: How is the intact ribosomal particle broken down within the large subunit?

Back 92

The large 60S ribosomal subunit contains three rRNA species (the 5S, 5.8S, and 28S rRNAs).

Front 93

Consider eukaryotic rRNA: How is the intact ribosomal particle broken down within the small subunit?

Back 93

The small 40S ribosomal subunit contains the 18S rRNA.

Front 94

Is considered the smallest of the RNA molecules

Back 94

tRNA.

Front 95

In it's secondary structure, is usually visualized as a cloverleaf folded back on themselves.

Back 95

tRNA

Front 96

How is the unique structure of tRNA maintained?

Back 96

Internal base pairing which results in loops.

Front 97

Molecule involved with the translation of the genetic message.

Back 97

tRNA

Front 98

Pseudouridine is an example of what?

Back 98

Methylated form of a tRNA base

Front 99

Dihydrouridine is an example of what?

Back 99

Methylated form of a tRNA base

Front 100

Methylation?

Back 100

Addition of a methyl group to a substrate

Front 101

True or False. Each tRNA carries a specific amino acid.

Back 101

True.

Front 102

True or False. ATP is necessary to link amino acids to the appropriate tRNA.

Back 102

True.

Front 103

True or False. There is at least 1 tRNA for the 20 amino acids.

Back 103

True.

Front 104

Aminoacyl tRNA synthetase?

Back 104

An enzyme that catalyzes the esterification of a specific amino acid to the appropriate tRNA.

Front 105

Anticodon?

Back 105

A unit made up of three nucleotides that correspond to the three bases of the codon on the mRNA molecule.

Front 106

What would mostly likely be the anticodon for lysine (AAA)?

Back 106

The anticodon of a lysine tRNA might be UUU.

Front 107

Pseudouridine and dihydrouidine are involved in?

Back 107

The binding of the ribosome and the aminoacyl-tRNA synthetase.

Front 108

Approximately what percentage of chromosomal DNA encodes synthesis of rRNA and tRNA in the cell?

Back 108

Less than 1%.

Front 109

Which RNA molecule(s) is least stable?

Back 109

mRNA

Front 110

How does the bacterial cell make rRNA and tRNA?

Back 110

The molecules are excised from large primary transcripts.

Front 111

RNA is synthesized in which direction?

Back 111

5'PO4 to 3'OH direction

Front 112

True or False. During RNA synthesis, only one of the DNA strands is transcribed in any given DNA region.

Back 112

True.

Front 113

When does RNA synthesis begin?

Back 113

With the binding of RNA polymerase to a promoter on DNA.

Front 114

Promoters?

Back 114

Specific DNA sequences, usually 20-200 bases long.

Front 115

This sequence is found as part of all prokaryotic promoters?

Back 115

TATAAT, known as the pribnow box

Front 116

This sequence is located about 35 base pairs upstream from the polymerization start site.

Back 116

TTGACA, known as the 35 sequence

Front 117

How did they discover promoters?

Back 117

Mixed RNA polymerase with DNA. Treated mixture with DNAase leaving region bound to RNA polymerase intact. Sequenced this "intact" DNA region. Discovered promoter region.

Front 118

List the 5 stages of RNA synthesis.

Back 118

1. Promoter recognition
2. Unwinding
3. Initiation
4. Elongation
5. Termination

Front 119

This subunit recognizes specific binding sites and ensures that the RNA polymerase forms stable associations with DNA only at promoters

Back 119

Sigma subunit

Front 120

This sequence causes the RNA polymerase to pause and terminates RNA synthesis

Back 120

The termination sequence

Front 121

Rho factor (p factor)?

Back 121

A prokaryotic protein involved in the termination of transcription

Front 122

Consider RNA synthesis: Which type of RNA terminator results in a hairpin formation in the new chain?

Back 122

Rho independent terminator

Front 123

For protein synthesis In bacteria, the initiating amino acid is a formylated version of what?

Back 123

Methionine

Front 124

The formylated version of methionine is specified by the codon?

Back 124

AUG and GUG

Front 125

How is the initiation complex during protein synthesis formed?

Back 125

The initiation complex is formed from the binding of the 30S ribosomal subunit to the initation codon, AUG or GUG on the mRNA.

Front 126

Establishes the reading frame for the mRNA.

Back 126

The initiation codon

Front 127

N-formylmethionine or fmet?

Back 127

formylated version of methionine

Front 128

Shine Delgarno sequence

Back 128

A purine rich region that precedes the 5' end of the initiation AUG codon

Front 129

The initiation step of protein synthesis requires what (in prokaryotes)?

Back 129

Requires a 30S ribosomal subunit, mRNA, fmet-tRNA, 3 protein initiation factors (IF1, IF2, IF3) and GTP.

Front 130

What does the protein initiation factor IF3 do?

Back 130

Catalyzes the dissociation of the 70S ribosome into individual subunits.

Front 131

What does the protein initiation factor IF2 do?

Back 131

Involved in the position of the fmet-tRNA to the correct codon on the 30S subunit. GTP is also involved here.

Front 132

What does the initiation factor IF1 do?

Back 132

assists the IF3 in binding to the 30S subunit to the mRNA.

Front 133

Which protein initiation factor assists IF3 in binding to the 30S subunit to the mRNA?

Back 133

IF1

Front 134

During protein synthesis, when does elongation begin?

Back 134

Elongation begins with the binding of an aminoacyl-tRNA to the complementary codon on the mRNA at the ribosomal site.

Front 135

During elongation of protein synthesis, this factor mediates the entry of the aminoacyl-tRNA into a free site of the ribosome.

Back 135

EF-Tu (elongation factor thermo unstable)

Front 136

During elongation of protein synthesis, this factor serves as the guanine nucleotide exchange factor, catalyzes the release of GDP from EF-Tu.

Back 136

EF-Ts (elongation factor thermo stable)

Front 137

During elongation of protein synthesis, this factor catalyzes the translocation of the tRNA and mRNA down the ribosome at the end of each round of polypeptide elongation

Back 137

EF-G

Front 138

Promote the binding of incoming aminoacyl-tRNA molecules to the ribosome

Back 138

Elongation factors (EF-Tu, EF-Ts, EF-G)

Front 139

During elongation of protein synthesis, a peptide bond is formed between which part of the amino acid?

Back 139

A peptide bond is formed between the alpha carbonyl group of the amino acid in the 'P" site of the ribosome and the alpha amino group of the amino acid at the "A" site of the ribosome.

Front 140

What type of bond is between the tRNA in the "P" site and it's amino acid?

Back 140

A ester bond.

Front 141

During elongation of protein synthesis, what is translocation?

Back 141

The ribosomal movement along the mRNA by one codon length in the 5' to 3' direction.

Front 142

During elongation of protein synthesis, translocation requires which elongation factors?

Back 142

EF-G, and the hydrolysis of GTP

Front 143

Protein synthesis continues until the ribosome reaches one of three nonsense or termination codons. List them.

Back 143

UAA, UGA, UAG

Front 144

Where are the termination codons located?

Back 144

On the mRNA strand

Front 145

When would a protein release factor bind to the ribosome?

Back 145

Once one of the nonsense or termination codons are read.

Front 146

During termination of protein synthesis, these hydrolyze the ester bond that holds the last tRNA that entered the ribosome

Back 146

Protein release factors

Front 147

Very little mRNA is required by cells for protein synthesis. How is this achieved?

Back 147

A single mRNA can have several ribosomes attached to it (polyribosome), thus very little mRNA is required by cells for protein synthesis.

Front 148

Operon regulation involving the binding of a repressor to the operator, preventing transcription.

Back 148

Negative regulation

Front 149

Operon regulation in which an effector molecule activates a promoter, no inhibition is overridden.

Back 149

Positive regulation

Front 150

Activator proteins bind to DNA and promote transcription

Back 150

Positive transcriptional control

Front 151

Repressor proteins bind to DNA then inhibits initiation of transcription.

Back 151

Negative transcriptional control

Front 152

Name the three enzymes involved in lactose uptake and utilization

Back 152

beta-galactosidase, beta-galactoside permease, and thiogalactoside transacetylase

Front 153

Hydrolyzes lactose into glucose and galactose

Back 153

beta-galactosidase

Front 154

transports the sugar into the cell

Back 154

b-galactoside permease

Front 155

Activator proteins bind to DNA and promote transcription

Back 155

Positive transcriptional control

Front 156

Repressor proteins bind to DNA then inhibits initiation of transcription.

Back 156

Negative transcriptional control

Front 157

Name the three enzymes involved in lactose uptake and utilization

Back 157

beta-galactosidase, beta-galactoside permease, and thiogalactoside transacetylase

Front 158

During lactose uptake and utilization, this enzyme hydrolyzes lactose into glucose and galactose

Back 158

beta-galactosidase

Front 159

During lactose uptake and utilization, this enzyme transports the sugar into the cell

Back 159

b-galactoside permease

Front 160

During lactose uptake and utilization, this enzymes function is unknown

Back 160

Thiogalactoside transacetylase

Front 161

If both glucose and lactose is present, is the lac operon needed?

Back 161

The lac operon is not needed.

Front 162

True or False. cAMP level regulates the activity of the lac operon

Back 162

True.

Front 163

If the cAMP level in bacteria is high, would the lac operon be on or off?

Back 163

cAMP receptor proteins are a positive regulator of the lac operon, therefor high levels of cAMP would turn the lac operon on.

Front 164

The tryptophan operon functions when?

Back 164

Functions only when tryptophan is NOT present

Front 165

Tryptophan operon is an example of what type of inhibition?

Back 165

Feedback inhibition

Front 166

If tryptophan is low?

Back 166

Repression is inactive, and transcription occurs

Front 167

If tryptophan is high?

Back 167

Binds to repressor with a "corepressor", sits on operon, trancription does not occur.

Front 168

Consider the tryptophan operon: In the absence of the corepressor, is tryptophan made?

Back 168

In the absence of the corepressor, the RNA polymerase is able to bind to the promoter region, tryptophan is made.

Front 169

Consider the tryptophan operon: Does tryptophan increase or decrease the affinity of the repressor protein for the operator?

Back 169

Increases affinity of the repressor! High levels of typ repress the production of tryptophan. Low levels of typ initiate the production of tryptophan.

Front 170

On the trp operon, where is the trpL located?

Back 170

Between the trpO and trpE region.

Front 171

Attenuator?

Back 171

Refers to a specific regulatory sequence that, when transcribed into RNA, forms hairpin structures to stop transcription when certain conditions are met.

Front 172

Describe attenuation as it pertains to the trp operon

Back 172

Attenuation is a second mechanism of negative feedback in the trp operon. Provides a stop sequence that is synthesized resulting in the termination of the transcription of the genes. trpL (leader) contains this sequence. when trp low, leader not synthesized.

Front 173

Diauxic growth? Example?

Back 173

A growth pattern in which there are 2 exponential phases of growth. E.coli growth in the presence of glucose and lactose. Glucose will be utilized first, then lactose.

Front 174

Inheritable change in the sequence of DNA

Back 174

Mutation

Front 175

Organisms that have undergone mutation. a phenotypic change is expressed

Back 175

Mutants

Front 176

The original form of a mutant is?

Back 176

the wild type

Front 177

A mutation that can occur naturally

Back 177

Spontaneous mutation

Front 178

A mutation that is the result of a chemical or radiation impact on genes

Back 178

Induced mutation

Front 179

Involves a single substitution in a base

Back 179

Point mutation

Front 180

A point mutation that occurs on the third position of the codon

Back 180

Silent mutation

Front 181

Will a silent mutation effect the amino acid coded by the affected area of the DNA

Back 181

NOPE

Front 182

A mutation in which the substitutions are in the first and/or second position of the codon

Back 182

Missense mutation

Front 183

Which type of mutation can result in a disfunctional protein?

Back 183

Missense mutation

Front 184

A mutation which results in the formation of a nonsense codon

Back 184

Nonsense mutation

Front 185

Which type of mutation can result in premature termination of protein synthesis

Back 185

nonsense mutation

Front 186

A mutation in which segments of the genome is removed

Back 186

Deletion

Front 187

A mutation in which one or more bases are added to the DNA

Back 187

Insertions

Front 188

Resulting from either a single base deletion or insertion, can change the amino acid sequence of the protein

Back 188

Reading frameshift

Front 189

Mutated base is changed back into it's original form

Back 189

Back mutation

Front 190

Mutations that overcome or suppress the effects of the initial mutation without alteration in the original gene

Back 190

Suppressor mutation

Front 191

Mutagenic agent which causes the formation of pyrimidine dimers in chromosomes

Back 191

UV radiation

Front 192

Chemical that can substitute for nucleotide (bases)

Back 192

base analogs

Front 193

Give an example of a base analog

Back 193

5-Bromouracil. Substitutes for thymine. This will bind with guanine instead of adenine. leads to errors in replication

Front 194

Replacement of a purine by a different purine or a pyrimidine for a different pyrimidine

Back 194

Transistions

Front 195

Mutations that overcome or suppress the effects of the initial mutation without alteration in the original gene

Back 195

Suppressor mutation

Front 196

Mutagenic agent which causes the formation of pyrimidine dimers in chromosomes

Back 196

UV radiation

Front 197

Chemical that can substitute for nucleotide (bases)

Back 197

base analogs

Front 198

Give an example of a base analog

Back 198

5-Bromouracil. Substitutes for thymine. This will bind with guanine instead of adenine. leads to errors in replication

Front 199

Replacement of a purine by a different purine or a pyrimidine for a different pyrimidine

Back 199

Transistions

Front 200

Mutations that overcome or suppress the effects of the initial mutation without alteration in the original gene

Back 200

Suppressor mutation

Front 201

Mutagenic agent which causes the formation of pyrimidine dimers in chromosomes

Back 201

UV radiation

Front 202

Chemical that can substitute for nucleotide (bases)

Back 202

base analogs

Front 203

Give an example of a base analog

Back 203

5-Bromouracil. Substitutes for thymine. This will bind with guanine instead of adenine. leads to errors in replication

Front 204

Replacement of a purine by a different purine or a pyrimidine for a different pyrimidine

Back 204

Transistions

Front 205

An alkylating agent that acts at the DNA replication fork causing crosslinking of the DNA strands and errors in replication

Back 205

N-methyl-N'-nitro-N-nitrosoguanidine (NTG)

Front 206

DNA repair mechanism in bacteria that corrects damage that causes distortion in the DNA helix

Back 206

Excision repair

Front 207

Give an example of excision repair

Back 207

T-T dimers from UV radiaiton

Front 208

DNA repair mechanism in bacteria the cleaves the covalent linkages between damaged pyrimidines

Back 208

Photoreactivation

Front 209

Which DNA repair mechanism has a light activated enzyme, photolyase?

Back 209

Photoreactivation

Front 210

Which repair mechanism does not require the removal and replacement of bases?

Back 210

Photoreactivation

Front 211

What enzyme removes the base during DNA repair?

Back 211

glycosylases

Front 212

True or False. DNA polymerase I removes the bases during DNA repair, DNA ligase joins the fragments

Back 212

True

Front 213

DNA repair mechanism imployed when DNA damage is severe. Which genes are involved?

Back 213

SOS response. Involves 17 genes, expression is controlled by the lexA and recA genes

Front 214

Method used to detect auxotrophs from the prototrophs (wild type strain)

Back 214

Replica Plating

Front 215

Bacterial DNA transfer that involves the insertion of naked DNA from a donor cell into a recipient cell.

Back 215

Transformation

Front 216

Bacterial DNA transfer that involves bacterial viruses (phages). The phage is the vector of the transfer of the DNA material.

Back 216

Transduction

Front 217

Bacterial DNA transfer that involves contact between a donor and recipient cell.

Back 217

Conjugation.

Front 218

A bacterial test uses to screen for carcinogens that otherwise cause mutations in bacteria

Back 218

Ames Test

Front 219

Bacterial test that measures the reversion of histindine auxotrophs in Salmonella typhimurium, to histidine prototrophs

Back 219

Ames Test

Front 220

Involves the introduction of bacteriophage DNA into a cell

Back 220

Transfection

Front 221

A bacteriophage serves as a vehicle for transfer of bacterial DNA from one bacterium to another

Back 221

Transduction

Front 222

What are the two ways in which transduction can occur?

Back 222

Generalized or Specialized

Front 223

Which form of transduction is restricted?

Back 223

Specialized transduction

Front 224

Transducing phage particles that lack a full complement of host DNA. These particles are unable to carry through the complete lytic cylcle.

Back 224

Defective phages.

Front 225

In which type of transduction is the probability of a given gene being transferred to a recipient cell increased?

Back 225

Specialized transduction

Front 226

Type of transduction that only occurs with temperate bacteriophages (those able to incorporate their DNA into host chromosomes without cell lysis).

Back 226

Specialized transduction

Front 227

Type of transduction in which the progeny bacteriophage lacks a complete phage genome.

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Specialized transduction

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The galactose gnes and lambda phage is an example of which transduction

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Specialized transduction

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Type of transduction in which the transducing phage DNA is not incorporated into the host chromosome. The phage DNA neither replicates nor is it destroyed. Rather it is transmitted in the daughter cells as the cell divide by binary fission becoming less and less apparent

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Abortive Transductions

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Occurs when a normal temperate bacteriophage lysogenizes a cell and one or more genes of the prophages are expressed

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Lysogenic conversion

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Corynebacterium diphtheriae infected with the phage beta is an example of what

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Lysogenic conversion

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The newly integrated genetic material in the lysogeny cycle

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Prophage

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Typically considered the main method of viral replication, results in the destruction of the infected cell.

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Lytic cycle

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Characterized by integration of the bacteriophage nucleic acid into the host bacterium's genome

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Lysogenic cycle

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Erythrogenic toxin is a pathogenic lysogenic conversion of what organism?

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Streptococcus pyogenes

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Botulinium toxin is a pathogenic lysogenic conversion of what organism?

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Clostridum botulinum

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Cholera toxin is a pathogenic lysogenic conversion of what organism?

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Vibrio cholerae

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Lysogenic conversion is an example of which type of transduction?

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Specialized transduction