Microbiology Intro Tortora Exam 2 10Edition

Front 1

Physical requirements for microbial growth?

Back 1

Temperature: Minimum, Optimum and Maximum.
pH:
Osmotic pressure:

Front 2

Acidophiles grow in ________ environment.

Back 2

Acidic

Front 3

Most bacteria grow between pH of ___ and ___.

Back 3

6.5 to 7.5

Front 4

Molds and yeast grow between pH of ___ and ___

Back 4

5 - 6

Front 5

Plasmolysis

Back 5

shrinking of the cell's cytoplasm

Front 6

What causes plasmolysis?

Back 6

Hypertonic environments, the increase in salt or sugar.

Front 7

Extreme or obligate halophiles require?

Back 7

High osmotic pressure and salt. Eg. Dead Sea. (30% salt environment)

Front 8

Faculative halophiles tolerate?

Back 8

High osmotic pressure. (2% salt environment)

Front 9

Chemicals required in microbial growth

Back 9

Nitrogen
Sulfur
Phosphorus
Carbon
Trace elements (inorganic required in small amounts)

Front 10

Nitrogen is found in?

Back 10

Amino acids, proteins

Front 11

Most bacteria decompose

Back 11

proteins

Front 12

Some bacteria use

Back 12

NH4+ andNO3-

Front 13

Sulfur is found

Back 13

in amino acids, thiamine, biotin

Front 14

Phosphorus is found in

Back 14

DNA, RNA, ATP and membranes

Front 15

PO4 3- is a source of _____.

Back 15

Phosphorus

Front 16

Trace elements

Back 16

inorganic elements required in small amounts. They are usually enzyme co factors: Iron, copper, zinc.
Naturally present in tap water.

Front 17

Carbon is a

Back 17

structural organic molecule, energy source
Chemoheterotrophs use organic carbon sources
Autotrophs use CO2.

Front 18

Mesophelics

Back 18

cause infection in warm blooded animals eg. humans

Front 19

Endospores may survive usual ________

Back 19

heat treatments. Eg. canning

Front 20

Most bactaria can withstand slight changes in ________ pressure

Back 20

osmotic

Front 21

Hypertonic environments

Back 21

increase salt or sugar, and cause plasmolysis. (water out of the cell)

Front 22

Extreme or obligate halophiles regire

Back 22

HIGH osmotic pressure

Front 23

Isotonic solution is ____________%NaCl

Back 23

0.85-0.9 %NaCl

Front 24

Hypertonic sloution is ______%Nacl

Back 24

10%

Front 25

Obligate anaerobes

Back 25

No oxygen, LACK ENZYMES. Grow in deep wounds with O2.

Front 26

Facultative anaerobes are

Back 26

both aerobic and anaerobic but BETTER IN O2 for growth.
They HAVE the enzymes.

Front 27

Aerotolerant anaerobes

Back 27

only grow anaerobically but continue in presence of O2

Front 28

Micro aerophilic

Back 28

O2 is reqired in low concentration
NO ENZYMES

Front 29

Aerobes need O2 as a final

Back 29

(e-) exceptor in electron transport pathway but toxic chemical and free radicals are produced. However, aerobes have enzymes to handle them.

Front 30

Catalase enzyme

Back 30

ID bacteria as catalase + or -

Front 31

Peroxidese enzyme and superoxide dismotase (SOD)

Back 31

break down superoxide free radicals (O2-)

Front 32

Organic growth factors

Back 32

vitamins, amino acids, purines and pyrimidines

Front 33

Culture medium

Back 33

nutrients are prepared for microbial growht. Has to be sterile before exposure.

Front 34

Inoculum

Back 34

introduction of microbes in to medium

Front 35

Culture

Back 35

Microbes growing in/on culture medium

Front 36

Complex polysaccharide

Back 36

derivative from alge and used used as solidifying agent for culture medai in Petri dishes, slants and deeps in lab.

Front 37

Generally not metabolized by microbes

Back 37

complex polysaccharides

Front 38

Liqefies at 100 degrees celsius

Back 38

agar

Front 39

Agar solidifies at _______ degrees celsius

Back 39

-40

Front 40

Chemically defined media

Back 40

exact chemical composition is known

Front 41

Complex Media

Back 41

Exactract and digest of yeasts, meat or plants.
Nutrient broth (soup)
Nutrient agar

Front 42

Fastidious microbes

Back 42

Require many growth factors Eg. Lactobacilus

Front 43

Short chains of amino acids are digested by _______ ________

Back 43

most bacteria

Front 44

Reducing media

Back 44

Contains chemicals tioglycollate or oxyrase, that combine with O2 and drive it off

Front 45

Selective media

Back 45

supresses unwanted microbes and encourages disered microbes. Eg. Streptococus and not any other bacteria.

Front 46

Eosin Methylene Blue (EMB)

Back 46

isolated gram -ve coliforms

Front 47

Coli-type colonies are very ____ color.

Back 47

dark eg. lactose +

Front 48

Aerogenes-type colonies are less _______ color.

Back 48

dark eg. lactose -

Front 49

Differential media

Back 49

Makes it easier to distinguish colonies of desired organism
Eg. Tellurite-Glycine Agar: completly inhibits growth of coaguase-negative staphylococci

Front 50

Coagulase

Back 50

is an enzyme produced by staphloccoccus aureus that converts fibrogen to fibrin.

Front 51

Potassium tellurate

Back 51

Differential agent in the differential medium.
Coagulase-positive staphylococcus reduce tellurite produces black colonies.

Front 52

Media can be both ________ and _________.

Back 52

Differential and Selective

Eg. Mannitol ssalt agar. High salt selects for S. aureus and mannitol fermentation differentiates them from non-mannitol fermenting bacteria.

Front 53

Enrichment Media

Back 53

Encourages growth of desired microbe.

Front 54

A pure culture

Back 54

contains only ONE SPECIES or STRAIN

Front 55

A colony

Back 55

is a population of cells arising from a singele cell or spore or from group of attached cells.
There is trillions of microorganisms in a colony.

Front 56

CFU

Back 56

Colony is often called "colony forming unit"

Front 57

Defferental meadia make it easier to

Back 57

distinguish colonies of desired organisms from other colonies.
Eg. red blood cells (sheep), certain kind of bacteria produce hemolysis on the plate.

Front 58

Manitol Salt Agar

Back 58

Salty medium has ptt indicator dye which changes color red to yellow if media mennitol is fermented.
Eg. Strep. Aureus (Pathogenic), Staph Epidermidis (Non-pathogenic)

Front 59

MacConkeg's Agar

Back 59

Both selective and differential. Bilesalts and crystal violet inhibits growth of G+ bacteria. It encourages lactose fermentors

Front 60

Selective Media

Back 60

suppresses growth of unwanted bacteria but encourages growth of desired ones.

Front 61

Sabourd's Media

Back 61

Dextraose with pH5.6 to isolate fungi that outgrow most bacteria.

Front 62

Dies such as brilliant green inhibit

Back 62

gram (+)ve bacteria.

Front 63

Preserving bacterial culture is done by:

Back 63

Deep freezing: -50 - -90 degreees celsius and
Lyophilization: freeze-drying

Front 64

Lyophilization

Back 64

freeze-drying. Bacteria are frozen at (-54)-(-95) degrees celsius and dehydrated in a vacuum (sublimation)

Front 65

Sublimation

Back 65

Dehydrating of bacteria in a vacum

Front 66

Preserved residue containing surviving microbes can be revived by __________ yealrs later.

Back 66

hydration

Front 67

Prokaryote ways of reproduction

Back 67

Binary fussion
Budding
Conidiospores (actinomycetes)
Fragmentation of filamets

Front 68

If 100 bacteria cells grow for 5 hours they produce

Back 68

1720320 new cells. (EXPONENTIAL GROWTH)

Front 69

Exponential Growth

Back 69

Bacterial cells multiply at very fast rates.

Front 70

Microbial growth count

Back 70

number of living cells or total count (viabel count)

Front 71

Generation time

Back 71

time for complete cell division (G)

Front 72

4 phases of growth cureve

Back 72

Lag
Log
Stationary
Deth

Front 73

Lag Phase

Back 73

Absorption of nutrients, active metabolites, synthesis of new protoplasm NO DIVISION
Length is variable in different species.

Front 74

Log Phase (Exponential Phase)

Back 74

Cells devide at a constant and max rate.
Number and mass of cells doubling every generation, and new cells grow exponentially. It is BALANCED GROWTH.

Front 75

Stationary phase

Back 75

Depletion of nutrients, build up of wastes (acids). Number of cells dying is the same as of those being created. CELLS ARE NOT UNIFORM, and are SMALLER than in log phase.

Front 76

Death Phase

Back 76

Cells gradually die off in decline phase.

Front 77

You can estimate bacterial numbers indirectly by:

Back 77

Metabolic activity
and
Dry weight

Front 78

Most Probable Number (MPN)

Back 78

Statistical estimating technique that is used to estimate #'s of bacteria in liquid medium.

Front 79

Fungus would be

Back 79

filtered, dried and weighed.

Front 80

Standard Plate Count

Back 80

Each bacterium grows in to a single colony which is reported as a number of colony forming units (C.F.U.)

Count by pour plate method or spread plate method.

Front 81

Filtration

Back 81

Bacteria stay on the surface of the membrane filter and then transferred to medium to be grown and counted.

Front 82

Direct microscopic count

Back 82

the microbes in the measure volume of bacteria are counted with the use of a specially designed slide (cell counter)

Front 83

Spectophotometer

Back 83

Indirect method of measuring microbial growth. It is used to determine turbidity (cloudiness) by measuring the amout of lifth that passes through a suspension of a cell.

Front 84

Measurement of metabolic activity of the population

Back 84

Indirect method of measuring microbial growth. Oxygen consumption and acid production......

Front 85

Completely independent neighboring microbes

Back 85

Two different oragnisms that live side by side.

Front 86

Mutualism

Back 86

each organism benefits from another

Front 87

Commensalism

Back 87

One organism benefits but causes no harm.

Front 88

Microbiota

Back 88

Normal microbes that live on humans and cause no harm unless they have an opportunity (opportunists)
Eg. cut

Front 89

Compete for space on humans and in colon.

Back 89

Bacteria and yeast

Front 90

Antibiotics may kill _____ bacteria and cause _______ one to grow

Back 90

good
pathogenic

Front 91

Moisture

Back 91

Most bacteria favor moisture

Front 92

T.B and Staph can withstand _____ and can live in ______ or food for _____ periods.

Back 92

drying
dust
long

Front 93

Drying food is one method of

Back 93

food preservation

Front 94

Photosynthetic bacteria

Back 94

reacquire light

Front 95

Most bacteria like __________ envirnoments.

Back 95

warm, dark, alkaline and moist environments.