Microbiology Test 2

Front 1

Microbial Growth:

Back 1

Increase in number of DNA, RNA, and protein synthesis

Front 2

Binary Fission:
1) definition
2) 2 step process

Back 2

Cell division

1) duplicate DNA
2) separate

Front 3

Bacterial example of Asexual Division, and amount of time required to divide?

Back 3

E. Coli divides every 20 minutes under optium conditions

Front 4

Generation time:

Back 4

Amount of time required for a population to double in 1-3 hours

Front 5

4 environmental factors that affect growth?

Back 5

Temperature
pH
Water availablity
oxygen

Front 6

Optimum temperature for human pathogens?

Back 6

37* C or 98.6* F

Front 7

Why is freezing important?

Back 7

inhibts the growth of bacteria, but does not kill bacteria.

(reason you don't refreeze food after allowing to thaw)

Front 8

Psychrophile:

Back 8

Grows best at 15* C

Front 9

What is the average refrigerator temperature?

Back 9

4-10* C

Front 10

Mesophile:

Back 10

Grow best from 10-39* C

(almost all human pathogens fall in this category)

Front 11

Thermophiles:

Back 11

grow from 39-60* C

(found in hot springs, water heater)
usually low in number

Front 12

Hyperthermophile:

Back 12

grow from 60-100* C

Front 13

enzymes are usually resistant to high temperatures, what can cause them to be immune?

Back 13

amino acid substitutions

Front 14

what temperature does the eukaryotic amoebae grow at?

Back 14

60* C

Front 15

What is the pH of the natural environment?

Back 15

5-9

Front 16

What is the optimal pH for most bacteria?

Back 16

6.5-7.5

Front 17

What form of growth is acid tolerant?

Back 17

Fungi

Front 18

what causes fruit spoilage?

Back 18

Fungi

Front 19

What bacteria can grow in the stomach, which has an acidity of 4?

Back 19

Helicobactor Pylori

Front 20

Where is H. Pylori said to originate from?

Back 20

House cat and well water

Front 21

Zoonatic disease?

Back 21

disease humans get from animals

Front 22

Hypertonic environment

Back 22

if there is a higher concentration of salts outside of the cell, the water from the bacteria will leave the cell to try to reach equilibrium, thus causing cell death

Front 23

what is an example of a bacteria that can grow on human skin because it is resistant to high salt concentrations?

Back 23

Staphylococcus Aureus

Front 24

Why is a hypertonic environment important in sterilization and food preservation?

Back 24

Salt can be used to dehydrate meat etc. and cause bacterial cells to die because of dehydration

Front 25

what are the three different forms of oxygen requirements?

Back 25

Obligate aerobe
obligate anaerobe
faculatative anaerobe

Front 26

Obligate Aerobe:

Back 26

bacteria that can grow only in the PRESENCE of oxygen

Front 27

Obligate Anaerobe:

Back 27

Bacteria that can grow only in the ABSENCE of oxygen

Front 28

Facultative Anaerobes:

Back 28

Bacteria that can grow in the absense of oxygen, but will use oxygen if it is present

Front 29

What are 3 forms of culture media?

Back 29

Chemically defined media
Complex media
Selective media

Front 30

Chemically defined media:

Back 30

Exact chemical composition is known (every amino acid, vitamin, sugar, etc)
Not used often

Front 31

Complex Media

Back 31

Exact chemical composition varies from batch to batch

contains complex aditives such as milk, blood, meat digest, etc.

Front 32

What kind of complex media is commonly used in medical situations to cultivate human pathogens?

Back 32

5% sheep blood agar

Front 33

Selective media:

Back 33

Designed to suppress the growth of unwanted bacteria

can contain antibiotics or salts

Front 34

Microbial Control:

Back 34

not always killing, but sufficiently inhibiting growth (key to regrigerator)

Front 35

Sterilization;

Back 35

The process of destroying or removing all forms of microbial life including spores and virus'

Front 36

what are the 5 ways to sterilize?

Back 36

Moist heat
dry heat
gas
ionizing radiation
non-ionizing radiation

Front 37

Most heat sterilization:

Back 37

121* C for 15 minutes under 15 obs of pressure

boiling water will kill most vegetative forms and bacteria (boiled for 10 minutes)

Front 38

Dry Heat:

Back 38

170* C for 2 hours

important for cooking meat

Front 39

Gas:

Back 39

4-18 hours exposure inEthalene oxide

important for sterilizing heat sensitive materials

Front 40

Autoclave:

Back 40

machine that uses moist heat and pressure to sterilize objects

Front 41

Ionizing Radiation:

Back 41

Penetrates very well
Gamma rays often used
no residual radioactivity

Front 42

non-ionizing radiation:

Back 42

does not penetrate well
no very effective at killing MO's
ex. microwave

Front 43

Disinfection:

Back 43

Process of destroying vegetative pathogens, but not necessarily sproes or virus'

does not mean sterilized

Front 44

7 ways to disinfect:

Back 44

PHENOL is a boy who has a HALO(gens) because he doesn't drink ALCOHOL or listen to HEAVY METAL. ALDEHYDE is a girl who OXIDIZES (OXIDIZING AGENT) her brain with QUATERNARY AMMONIA.

Front 45

how do most disinfectants function?

Back 45

Denatures proteins and disrupts cell membranes

Front 46

Disinfectant:

Back 46

the application of antimicrobial compounds to NON-LIVING objects

Front 47

Antiseptic-

Back 47

the application of antimicrobial compounds to LIVING TISSUE

Front 48

Phenol:

Back 48

Lysol
hexochlorophene
cholohexidine

Front 49

Halogens:

Back 49

Consist primarily of Iodine and Chlorine

ex. tincture of iodine(dissolved in alcohol)
Chlorine Bleach
Betadine (sticky antiseptic)

Front 50

Alcohols:

Back 50

ETOH- ethyl alcohol (result of fermentation)
hospitals don't use because people drink it

Isopropyl

Front 51

Heavy Metals:

Back 51

Gold, copper, silver, mercury

Copper pipes in plumbing
copper sulfate in pools

Front 52

Soaps and Detergents:

Back 52

reffered to as emolsification agents because the coat things.

Do not kill MO's in and of themselves, must have additives

Front 53

Aldehydes:

Back 53

Farmaldehyde
Glutaraldehyde (cold sterilization)

Front 54

Oxidizing Agents:

Back 54

H2O2
benzoyl Peroxide

Front 55

Quaternary Ammonia

Back 55

Compounds
mouthwash (cepacol)

Front 56

What specific bacteria are hard to kill with disinfectants?

Back 56

Hepatitis and microbacterium (TB)

Front 57

Nucleic Acids:

Back 57

Long polymers of nucleotides that make DNA and RNA

Front 58

What cause changes in the information carried and transferred in DNA/RNA?

Back 58

variability in nitrogenous bases

Front 59

How many units in RNA?

Back 59

80-200,000 nucleotide units

Front 60

How many units in DNA?

Back 60

several million nucleotide units

Front 61

Pyrimidines:

Back 61

one ring structures:
Thymine
Uracil
Cytosine

Front 62

Purines

Back 62

two ring structures:
Adenine and Guanine

Front 63

Two DNA strands are said to be:

Back 63

complimentary (A-T, C-G)
and
anti-parallel (one strand will be the 5' end while the other is the 3' end)

Front 64

Each DNA/RNA molecule contains:

Back 64

Phophate group, sugar, nitrogenous base

Front 65

A binds to ? in DNA?

Back 65

T

Front 66

C binds to what?

Back 66

G

Front 67

A binds to what in RNA?

Back 67

U

Front 68

T is in what?

Back 68

DNA

Front 69

U is in what?

Back 69

RNA

Front 70

DNA is ? because each ?? recieves a single strand from the ??

Back 70

semiconservative
daughter chromatids
parent cell

Front 71

What direction does DNA replicate in?

Back 71

5' to 3'

Front 72

What are the gaps in the discontinuous strand?

Back 72

Okazaki fragments

Front 73

What attaches okazaki fragments?

Back 73

DNA Ligase

Front 74

DNA polymerase:

Back 74

Attaches the newly formed DNA strands

Front 75

Main enzyme thatuncoiles the super coild in bacterial DNA?

Back 75

DNA gyrase

Front 76

Transcription:

Back 76

the synthesis of a complimentary strand of RNA from a DNA template

Front 77

What direction is RNA synthesized in?

Back 77

5' --> 3'

Front 78

Sense strand:

Back 78

portion of DNA that undergoes transcription

Front 79

non-sense strand:

Back 79

portion of DNA that does not undergo transcription

Front 80

3 types of RNA:

Back 80

mRNA
tRNA
rRNA

Front 81

messenger RNA

Back 81

bears the message for protein synthesis

Front 82

transfer RNA

Back 82

carries the amino acids to the site of protein synthesis

Front 83

ribosomal RNA

Back 83

a component of the ribosomes

Front 84

Gene:

Back 84

a segment of DNA that codes for polypeptides by a messenger, ribosomal, and transfer RNA

Front 85

where are genes located in both eukaryotic and prokaryotic cells?

Back 85

chromosomes

Front 86

What is the flow of genetic information?

Back 86

DNA--> RNA (transcription) --> protein(translation)

Front 87

amino acid sequence in protein is directly related to the.....

Back 87

nitrogenous base in DNA

Front 88

DNA is a template for....

Back 88

amino acid sequence

Front 89

at one particular time, only ? strand is synthesized

Back 89

one

Front 90

what is the product of transcription?

Back 90

RNA

Front 91

RNA polymerase:

Back 91

responsible for RNA synthesis

Front 92

once synthesized, where does RNA travel?

Back 92

cytoplasm

Front 93

Eucaryotic RNA arises from what process?

Back 93

post transcriptional modification

Front 94

Split Genes:

Back 94

different segments within RNA in eukaryotic cells

Front 95

what happens in post transcription modification?

Back 95

introns are discarded from the RNA and the only exons remain to make up the final product

Front 96

Junk RNA

Back 96

97% of human DNA that appear to be introns

Front 97

Terminator region of the DNA:

Back 97

the endpoint for transcription of a gene

Front 98

Translation:

Back 98

the process in which the genetic message carried by the mRNA directs the synthesis of polypeptide chains with the aid of ribosomes

Front 99

Codon

Back 99

a set of 3 nucleotide bases that code for a single amino acid

Front 100

Exons:

Back 100

Regions of DNA that undergo transcription and end up in the final product

Front 101

Introns:

Back 101

regions that undergo transcription but are removed from the RNA transcript

Front 102

Translation:

Back 102

Copy strand (mRNA goes to a ribosome and the ribosome makes a polypeptide chain using the code the mRNA carries as a template

Front 103

Number of Amino acids:

Back 103

21

Front 104

how many nitrougenous bases in a codon?

Back 104

3

Front 105

how many possible codon's?

Back 105

64

Front 106

how many sense codons?

Back 106

61

Front 107

how many non-sense codons?

Back 107

3

Front 108

Sense Codon:

Back 108

code for insertion of amino acids into a polypeptide chain

Front 109

Non-sense codon:

Back 109

UGA, UAG, UAA
will cause the ribosome to disassociate from the mRNA and stop translation

Front 110

A change in the DNA base sequence will cause....

Back 110

a change in the amino acid sequence

Front 111

Point Mutation:

Back 111

A single base at one point in the DNA is replaced with a different base

Front 112

Frame shift mutation:

Back 112

when one or more nucleotide base pairs are deleted or inserted into DNA

Front 113

What does frame shift mutation lead to?

Back 113

a shift in the reading frame of the mRNA

Front 114

Chemical mutagens:

Back 114

a chemical that causes a mutation
(main cause of mutation)

Front 115

Almost all chemical mutagens are:

Back 115

base analogs

Front 116

Base Analog:

Back 116

chemicals that are similar to nitrogenous bases and get incorporated into DNA

Front 117

Example of base analog:

Back 117

2-amino purine
incorporated in place of adenine but pairs with cytosine
causes incorrect RNA and therefore incorrect proteins

Front 118

What is the easiest way to tell if a chemical can be incorporated to cells?

Back 118

use bacteria because all DNA is the same, and they reproduce and divide so quickly.

Front 119

Ames Test:

Back 119

a test that uses a strain of alminella to test chemicals for their mutagenicity and thus their potential carcinogenicity

Front 120

What does UV light do to thymine?

Back 120

causes thymine dimmers

Front 121

Thymine dymmer:

Back 121

if uv light hits a segmant of DNA that has two thymins, (TT), the UV ray can cause them to fuse together, causing it to be read as 1 thymine instead of two

Front 122

what is the general spontaneous mutation rate?

Back 122

1 per 10^9 replicated base pairs

Front 123

How many base pairs is the average gene?

Back 123

10^3

Front 124

what is the average mutation rate?

Back 124

1 to 1,000,000

Front 125

vast majority of ? are ? in nature and are often ?

Back 125

mutations, harmful, carcinogenic

Front 126

how do you block the transfer of antibiotic resistance?

Back 126

block the transfer of DNA between bacteria

Front 127

what are the 3 types of bacterial DNA transfer?

Back 127

Transformation
Conjugation
Transduction

Front 128

Transformation:

Back 128

the transfer of asked pieces of DNA from one bacteria to another

Front 129

what is the term for DNA picked up by a bacterial cell in transformation?

Back 129

recombinant DNA

Front 130

Conjugation:

Back 130

DNA is passed as plasmids are transferred from one bacteria to another

Front 131

Plasmid:

Back 131

small, circular, extrachromosomal DNA

Front 132

Transduction:

Back 132

genetic transfer mediated by virus' called bacteriophages

Front 133

Bacteriophage:

Back 133

a virus that afects only bacteria
(looks like a spaceship)

Front 134

Genetic Engineering:

Back 134

the deliberate modification of an organisms genetic information by directly changing its uceotide sequence

Front 135

Recombanant DNA technology:

Back 135

the collection of methods used in genetic engineering

Front 136

? plays a constant and important role in biotechnology

Back 136

bacteria

Front 137

how is diabetes an example of biotechnology?

Back 137

scientists found through studies on insulin that we can let bacteria make a desired product and then give that product to a definicient individual

Front 138

Gene Therapy:

Back 138

concept of recoding a defective DNA sequence
not yet effective

Front 139

Why is it difficult to use eukaryotic cells in genetic ingineering?

Back 139

DNA must cross a large area to get to the nucleus

Front 140

RFLP

Back 140

Restriction Fragment Length polymorphism

requires about a quarter size amount of sample

Front 141

PCR (what does the acronym stand for)

Back 141

Polymerase chain reaction

Front 142

rDNA

Back 142

recombanant DNA products

Front 143

examples of rDNA:

Back 143

hepatitis vaccine, HCG

Front 144

purpose of genetic probes

Back 144

helpful in identifying a bacterium or a genetic disease

Front 145

Probe:

Back 145

a DNA or RNA molecule which is used to locate a complimentary RNA or DNA by hybridizing with it

Front 146

Hybrid:

Back 146

double stranded nucleic acid in which the two strands differ in origin

Front 147

Aligonucleotide synthesis:

Back 147

production of short pieces of DNA 2-3 base pairs long

Front 148

Primers are used for?

Back 148

PCR -->manufacture copies of a segment of DNA

Front 149

In a stain or culture media you can:

Back 149

extract DNA, and then heat to see if it will bind to identify bacteria

Front 150

Who developed the polymerase chain reaction (PCR)?

Back 150

Kery Mulis

Front 151

Polymerase chain reaction:

Back 151

an in vitro reaction in which a specific region of DNA is amplified many times by repeated synthesis of DNA using DNA polymerase and specific primers to define the ends of the amplified region

Front 152

what is the application of PCR?

Back 152

makes large quantities of a particular DNA sequence

Front 153

PCR process:

Back 153

1) synthesize graments with sequences identical to those flanking the targeted sequence
2) heat denature dsDNA to separate complementary strands
3) add primers in excess and lwer temp to allow primers to anneal to DNA
4) add nucleoside triphosphates and DNA polymerase
5) DNA polymerase extends the primers and synthesizes copies of target DNA sequence
6)repeat heating and cooling
7) use heat stable polymerase from a thermophilic bacteria

Front 154

what are 4 aspects of recombanant DNA technology?

Back 154

restriction in endonucleases
DNA ligases join ends of DNA
plasmids
gram negative bacteria