Microbiology Exam 3

Front 1

What is th anticodon for the codon GAU?

Back 1

CUA

Front 2

Which nitrogenous bases are pyrimidine?

Back 2

C & T

Front 3

Which nitrogenous bases are Purines?

Back 3

A & G

Front 4

Transfer RNA (tRNA) ias also known as an _________ molecule.

Back 4

interpreter

Front 5

What is meant when we say DNA has anti-parallel strands?

Back 5

One strand goes up, one goes down - they "read" in opposite directions

Front 6

What are the components of the DNA nucleotide?

Back 6

Deoxyribose, nitrogenous base, phosphate group

Front 7

What are the components of the RNA nucleotide?

Back 7

Ribose, nitrogenous base, phosphate group

Front 8

What is the monomer of the polynucleotide molecule?

Back 8

nucleotides

Front 9

Name the enzyme that synthesizes DNA during replication

Back 9

DNA polymerase

Front 10

In what direction does DNA synthesis occur?

Back 10

5' to 3'

Front 11

Where does DNA replication initiate on the DNA molecule?

Back 11

origin of replication

Front 12

What are the substrates for DNA replication?

Back 12

nucleotide triphosphates

Front 13

Where does the energy for DNA replication come from?

Back 13

from the hydrolysis of 2 phosphates from the triphosphate substrate

Front 14

Is DNA replication conservative or semi-conservative?

Back 14

semi

Front 15

What is a bacterial operon?

Back 15

Genes that are involved in a common process that are all regulated together as a single unit.

Front 16

What are polyribosomes?

Back 16

many ribosomes attached to and translating the same strand of mRNA

Front 17

Which operon is an example of gene repression?

Back 17

trp operon

Front 18

Which operon is an example of gene induction?

Back 18

Lac operon

Front 19

How many initiation (start) codons are there?

Back 19

1

Front 20

How many nonsense (stop) codons are there?

Back 20

3

Front 21

How many of the possible 64 triplet codons code for amino acids?

Back 21

60

Front 22

Why is the genetic code described as redundant?

Back 22

b/c several codons code for the same amino acid

Front 23

Why is the genetic code described as unambiguous?

Back 23

each triplet codon codes for 1 specific codon

Front 24

Why is the genetic code described as universal?

Back 24

Almost all organisms use the same code

Front 25

Name the enzyme used in the transcription of an RNA molecule from the template strand of DNA

Back 25

RNA polymerase

Front 26

Where on the gene does transcription initiate?

Back 26

@ the promoter region of the gene

Front 27

Where does transcription stop on the gene?

Back 27

when the RNA polymerase comes to the termination sequence

Front 28

RNA vs. DNA

Back 28

RNA: single stranded, uses U instead of T, uses ribose as the sugar.

DNA: dble stranded, uses T instead of U, uses deoxyribose as the sugar

Front 29

What direction as the mRNA translated?

Back 29

5' to 3'

Front 30

What molecule is used for energy during translation

Back 30

GTP - guanine triphosphate

Front 31

What are the two important sites on the tRNA molecule?

Back 31

The amino acid binding site and the anticodon site

Front 32

What is translocation (during the elongation process of translation)?

Back 32

It is when tRNA inside the ribosomes and move to the left and detatch, which allows the next tRNA to add its amino acid to the growing protein

Front 33

What binds to the stop codon during the termination process of translation?

Back 33

release factors

Front 34

Where does transcription take place in the prokaryotic and eukaryotic cell?

Back 34

prokaryotic: cytoplasm

eukaryotic: nucleus

Front 35

Where does translation take place in the prokaryotic and eukaryotic cell?

Back 35

cytoplasm

Front 36

What is coupled transcription-translation

Back 36

when both activities take place in the same compartment - as the the mRNA is being created, the ribosomes and tRNA can immediately begin to translate it before it is "finished" (only in prokaryotic cells)

Front 37

Genotype vs. Phenotype

Back 37

Geno: actual gene

Pheno: expresses trait

Front 38

haploid vs. diploid

Back 38

one set of genes vs. two sets

Front 39

What kind of mutations in the amino acid sequence can a base substitution (point mutation) in the DNA cause?

Back 39

missense or nonsense mutations

Front 40

What kind of mutations in the amino acid sequence can a deletion or insertion in the DNA cause?

Back 40

frameshift (major mutation!!)

Front 41

What are examples of mutagens

Back 41

chemicals (carcinogens), radiation

Front 42

what causes thymine dimers?

Back 42

UV radiation

Front 43

Name two ways thymine dimers can be fixed:

Back 43

exposure to light/photo-repair & excision repair by intracellular enzymes

Front 44

What is the basic taxonomic unit

Back 44

specie

Front 45

What are the three domains that all living organisms fall into on planet earth?

Back 45

Eukarya, Bacteria, Archaea

Front 46

Who is Linneaus?

Back 46

the man who developed the taxonomic nomenclature system

Front 47

What is a strain or subspecie?

Back 47

a bacteria/organism that is only slightly different from a species (only different by 1-2 genes)

Front 48

What are examples of morphological characteristics?

Back 48

bacterial shape, flagella, endospores, glycocallyx

Front 49

Name the Gram positive cocci that causes strep throat

Back 49

Streptococcus pyrogenes

Front 50

Name the Gram positive comma shaped rod that causes intense diarrhea due to production of a toxin

Back 50

Vibrio cholera

Front 51

Name the Gram negative diplococci that cause a sexually transmitted disease

Back 51

Neisseria gonorrhea

Front 52

DNA sequence homology vs. amino acid homology

Back 52

DNA sequnce = looking at the similarities in the actual sequence of bases\sequence of codons

amino acid = looking at the similarities in the sequence of amino acids

Front 53

Name the Gram negative aerobic bacilli that are transmittes from the environment and cause a respiratory infection

Back 53

Legionella pneumophilia

Front 54

Name the Gram negative bacilli that causes an intestinal infection, often seen among children in daycare centers

Back 54

Shigella dysentariae

Front 55

Name the spirochete that causes a sexually transmitted disease

Back 55

Treponema pallidum (syphilis)

Front 56

What are serological tests?

Back 56

tests that use antibodies to identify microrganisms

Front 57

Name differential staining procedures that are used to help identify bacteria

Back 57

gram stain, acid-fast stain, spore stain, capsule stain

Front 58

Name the bacteria that do not have a cell wall and causes a respiratory infection

Back 58

Mycoplasma pneumoniae

Front 59

Name the bacteria that cause ulcers

Back 59

Helicobacter pylori

Front 60

Name the Gram negative bacilli that cause a prolonged upper respiratory infection in children where the victims cough uncontrollably

Back 60

Bordetella pertussiss

Front 61

Name the Gram positive bacilli that form endospores and are transmitted from animals causing skin,intestinal, or respiratory infections

Back 61

Bacillus anthracis

Front 62

Name the intracellular parasite that can cause blindness if the eye infection is not treated

Back 62

Chlamydia trachomatis

Front 63

Are bacteria haploid or diploid?

Back 63

haploid

Front 64

Define plasmid

Back 64

Extrachromasomal, circular DNA that is smaller than regular DNA and replicated autonomously

Front 65

What are ribosomes made up of?

Back 65

proteins & RNA molecules

Front 66

define gene expression

Back 66

transcription + translation

Front 67

Define gene

Back 67

sequences of bases in DNA that code for a functional product. The functional unit of DNA.

Front 68

What is a F-pilus

Back 68

a sex pilus. Needed for bacterial conjugation

Front 69

How is the base composition of the DNA of an organism measured?

Back 69

% G+C

Front 70

What are the kingdoms under the domain Eukarya?

Back 70

Protista, Fungi, Plantae, Animalia

Front 71

Name and acid-fast, slow growing aerobic bacteria that causes a respiratory infection

Back 71

Mycobacterium tuberculosis

Front 72

Name two bacteria that are intracellular parasites. Which one requires an insect vector?

Back 72

Chlamydia trachomatis, Rickettsia rickettsii.

RR requires an insect vector

Front 73

What type of DNA sequences do restriction endonucleases bind to?

Back 73

pallindromic sequences

Front 74

What are the different ways DNA homology can be analyzed between two bacteria?

Back 74

Base composition, in-solution hybridization, DNA sequencing, & comparison of DNA fingerprints

Front 75

Name 3 ways bacteria may pick up genes from other bacteria:

Back 75

transformation, transduction, conjugation

Front 76

What is RTF? Where is it found?

Back 76

RTF is a gene that codes for the formation of a sex pilus. Found on the R plasmid

Front 77

What type of mutations do base analogs cause?

Back 77

missense and nonsense

Front 78

What type of mutations do intercalating agents cause?

Back 78

frameshift

Front 79

Which plasmid is required for conjugation?

Back 79

F-plasmid

Front 80

What is required for transduction to take place?

Back 80

A bacteriophage (a bacterial virus)

Front 81

Which plasmid has multi-antibiotic resistant genes and multi-heavy metal resistant genes?

Back 81

R-plasmid

Front 82

What is a missense mutation?

Back 82

mutation in the sequence of amino acids that changes the amino acid.

Front 83

What is a nonsense mutation?

Back 83

mutation in the amino acid sequence that prematurely ends the amino acid sequence (prematurely ends the protein)

Front 84

Induced mutation vs. spontaneous mutation

Back 84

induced= caused by outside forces (chemicals, radiation, etc.)

spontaneous= error caused by DNA/RNA polymerase

Front 85

Name the spirochete that is transmitted by a tick and may cause a bulls-eye rash

Back 85

Borrelia burdorferi (Lymes disease)

Front 86

Name the obligate anaerobe that forms endospores and produces a toxin that causes all muscles to contract

Back 86

Clostridium tetani (tetanus)

Front 87

Name the Gram positive irregularly-shaped bacilli that cause a repiratory infection and cause the formation of a pseudomembrane in the back of the throat

Back 87

Corynebacterium diphtheriae

Front 88

What is a codon?

Back 88

it is a set of three nitrogenous bases located on the DNA that code for a specific amino acid.

Front 89

What are restriction endonucleases? What are they used for?

Back 89

they are enzymes that recognize specific pallindromic sequences in DNA and cut the DNA into segments at those points.

They are used to cut up DNA for DNA fingerprinting.

Front 90

What is a transposon?

Back 90

segments of DNA that are able to move from one region to another.

Front 91

What is a bacteriocin?

Back 91

it is a toxin that kills other bacteria.

Front 92

Name 5 different plasmid bacteria may have:

Back 92

F=plasmid, R-plasmid, virulence plasmids, dissimilation plasmids, bacteriocinogens

Front 93

Bacterial transformation vs. transduction vs. conjugation

Back 93

transformation: small pieces of naked DNA are taken up by competent cells & recombined

Transduction: uses a bacteriophage to transfer small pieces of DNA

Conjugation: requires direst contact between donor and recipient via f-plilus, transfer long segments of DNA.

Conjugation:

Front 94

What does the initiation of translation entail?

Back 94

small subunit of ribosome binds to mRNA, a tRNA binds to the codon on the mRNA, and the large subunit of the ribosome attatches to the initiation tRNA.
Process requires energy and initiation factors

Front 95

Where are the ribosomes located in the prokaryotic and eukaryotic cell?

Back 95

cytoplasm