Chapter 6

Front 1

Microbial growth

Back 1

Hypertrophy

Increase in cell size

Front 2

Reproduction

Back 2

Hyperplasia

Increase in cell number

Front 3

2 types of requirements for growth

Back 3

Physical factors

Chemical factors

Front 4

Cardinal temperatures

Back 4

Minimum growth temp

Optimum growth temp

Maximum growth temp

Front 5

Minimum growth temp

Back 5

Lowest temp that a specific organism can grow

Front 6

Optimum growth temp

Back 6

Ideal temp for FASTEST growth of a specific organism

Front 7

Maximum growth temp

Back 7

Max temp that a specific organism can grow

Front 8

Physical requirement for growth

Back 8

Temperature

pH

Osmotic pressure

Front 9

Psychrophiles

Back 9

Cold loving

0 degrees Celsius --> 20 - 30 degrees Celsius

Front 10

Mesophiles

Back 10

Moderate loving

20 degrees Celsius ---> 40 - 45 degrees celcius

Front 11

Psychotrophs

Back 11

Specific for those that prefer human body temp

Front 12

Thermophiles

Back 12

-Heat loving

-40 degrees Celsius ---> under 80 degrees Celsius

-Anything over 65 degrees Celsius is an extreme thermophile

- above 110 degrees Celsius is protein denature

Front 13

pH

Back 13

Most bacteria grow between 6.5 and 7.5

Front 14

Alkalophiles

Back 14

Do well in alkaline environment

Few are higher than pH8

Front 15

Molds and yeasts pH

Back 15

Fungi kingdom

pH 5 &6

Only slightly acidic

Front 16

What maintains pH homeostasis?

Back 16

Buffers

Work with hydrogen ions

Front 17

Acidophilic

Back 17

Below 4 pH

Very few can grow at this environment

Front 18

Tonicity

Back 18

Concentrations of solutes

Front 19

Isotonic

Back 19

Equal

Front 20

Hypertonic

Back 20

More solutes

Front 21

Hypotonic

Back 21

Less solutes

Front 22

In a hypertonic solution, microbes undergo?

Back 22

Plasmolysis

Front 23

Plasmolysis

Back 23

Shrinkage of the cell's cytoplasm.

Separates cell membrane from cell wall

Most kill the organs

Front 24

Halophiles

Back 24

Salt loving

Can survive in hypertonic solutiin

Front 25

Availability vs presence of water?

Back 25

Just because something is there doesn't mean it's available

Front 26

All organisms need what chemical requirements?

Back 26

Carbon

Nitrogen

Phosphorus + sulfur

Front 27

Carbon makes up how much if dey weight?

Back 27

Makes up 50% of dey weight of a bacteria cell

Front 28

What is carbon needed for?

Back 28

Needed for all the organic compounds that a cell has to be able to make to survive.

Obtained from one or two sources: organic materials.

CO2 and organic compounds

Front 29

Niteogen makes up bow much of dry weight?

Back 29

Makes uo 14% of dey weight of a bacteria cell

Front 30

What is nitrogen us needed for?

Back 30

Needed for synthesis of proteins, nucleic acids & ATP.

Obtained from soil, protein catabolism and nitrogen fixation

Front 31

Nitrogen fixation

Back 31

Taking nitrogen from gas and use into a usable source

Front 32

Rhizobium is a genus that does what?

Back 32

Uses nitrogen fixation

Front 33

Phosphorus + Sulfur makes up how much of dry weight?

Back 33

4% of dry weight of bacterial cell

Front 34

Phosphorus + Sulfur needed for what?

Back 34

Needed for nucleic acid synthesis, production of phospholipids (cell membrane)

Front 35

On the basis of oxygen requirements, organisms are classified as?

Back 35

Obligate aerobes

Obligate anaerobes

Facultative anaerobes

Aerotolerant anaerobes

Microaerophiles

Front 36

Obligate aerobes

Back 36

Require oxygen to live

Growth is at top, as close as they can get to oxygen

Front 37

Obligate anaerobes

Back 37

No oxygen

As far as they can get from oxygen

Front 38

Facultative anaerobes

Back 38

Grow better with oxygen.

But can reproduce with limiting amounts.

Do better with oxygen.

Front 39

Microaerophilic

Back 39

A little bit of oxygen to reproduce

Front 40

Aerotolerant anaerobes

Back 40

Does not grow in presence of oxygen, but oxygen doesn't kill them

Front 41

Using oxygen for aerobic respiration produces what?

Back 41

Toxic byproduct

Front 42

Superoxide

Back 42

Free radicals (O2) are by products of aerobic respiration.

Front 43

Superoxide dismutase (SOD)

Back 43

Type of enzyme.

Helps aerobes break down superoxide free radicals.

Front 44

Free radicals produce what after being broken down by superoxide dismutase?

Back 44

Produces H2O2 after broken down

Front 45

Peroxide anions O2 2-

Back 45

Catalase and peroxidase.

Breaks down the toxic anions (H2O2) in order to survive with oxygen

Front 46

Hydroxyl radicals (OH-)

Back 46

Very strong oxidizing agents, cause damage in cells

Front 47

Free radicals

Back 47

Atoms or molecules with unpaired electrons. Highly reactive.

Front 48

What are free radicals symbolized by?

Back 48

By a dot.

Front 49

Culture media

Back 49

Any material prepared for the growth of bacteria in a lab

Front 50

Culture

Back 50

Microbes that grow and multiply in or on a culture medium

Front 51

Agar

Back 51

A solidifying agent for a culture medium that comes from seaweed

Front 52

Fastidious

Back 52

Picky, difficult to grow

Front 53

Chemically defined culture media

Back 53

Exact amount of each chemical component is known

Front 54

Reducing media

Back 54

Used for growing an aerobic media (decreases amount of oxygen)

Front 55

Complex media

Back 55

The exact amount of chemical composition is not known.

Most bacteria and fungi are grown with this tyoe of medium

Front 56

Selective media

Back 56

Inhibit growth if certain organisms and encourage growth of others

Example: EMB

Front 57

Eosin Methylene Blue

Back 57

Inhibit gram positive bacteria

Selects for gram negative bacteria

Front 58

Rose media

Back 58

Inhibits gram negative

Selective for gram positive bacteria

Front 59

Differential media

Back 59

Differentiates between different organisms growing on the same plate

Front 60

Differential media allows growth of what?

Back 60

Growth of certain organisms based on biochemical reaction

Front 61

Enriched media

Back 61

Indicates additional ingredients in media used primarily used for fastidious organisms

Example: blood agar plates

Front 62

Alpha hemolytic

Back 62

Incomplete lysis of RBC's.

Greenish halo.

More noticeable from bottom

Front 63

Beta hemolytic

Back 63

Complete lysis of RBC's

Clear zone around growth

Front 64

Gamma hemolytic

Back 64

No lysis of RBC's

No results

Front 65

Mannitol salt agar

Back 65

Used to identify halophiles.

7.5% salt concentration, inhibits most bacteria.

PH indicator: phenol red turns yellow when acid is produced

Front 66

Colony

Back 66

Groups of cells from single species

Front 67

Pure cultures

Back 67

One strain of a species

Usually obtained by streak plates

Front 68

Microbes can be preserved for long periods of time by?

Back 68

Deep- freezing 50 degrees celcius to 94 degrees Celsius.

Lyophilization

Front 69

Lyophilization

Back 69

Deep frozen then dehydrated then stored in sealed container.

End product is powder substance

Front 70

Bacterial division

Back 70

Growth of bacterial cultures such as binary fission.

Some bacteria reproduce by budding, aerial spore formation or fragmentatiin

Front 71

Population growth

Back 71

Increase of # of cells of a group of organisms of same species in same location

Front 72

Cell growth

Back 72

Hypertrophy of cell (increase in size)

Front 73

Growth rate

Back 73

Increase in cell number (hyperplasia) per unit time (min, hours, days)

Front 74

Generation time

Back 74

Time required for population to double in number.

Average time for population to double is 20 minutes

Front 75

Logarithmic representation of bacterial populations

Back 75

Bacterial division occurs according to a logarithmic progression

Front 76

4 phases of growth

Back 76

Lag phase

Log phase

Stationary phase

Death phase

Front 77

Lag phase

Back 77

Little to no hypoplasia.

A lot of metabolic activity cells start to reproduce, hypertrophy does occur

Front 78

Log (exponential growth) phase

Back 78

Every cell (population) has completed their generation time doubled in number

Front 79

Stationary phase

Back 79

Hyperplasia (new cell rate = death rate)

Front 80

Death phase

Back 80

Number of deaths are for greater than that of new cells

Front 81

Direct measurement of microbial growth

Back 81

Plate count

Filtration

DMC

Serial dilution

Front 82

Plate count

Back 82

Reflects number of viable organisms

Front 83

Pour plate

Back 83

Organism is put into Petri plate, warm broth media is put into plate.

Warmth can kill bacteria.

Organism are on bottom.

Don't know if alive or dead

Front 84

Spread plate method

Back 84

Media already solidified.

Occulation in surface

Front 85

Filtration

Back 85

Mixed culture.

Determine if one od these organism will be reproducing.

Depends on what type of organism depends on the filtration

Front 86

DMC

Back 86

Direct microscopic count.

Count every single organism.

Dead or alive.

Human error can occur.

Recounts can occur.

Front 87

Serial dilutions

Back 87

Systematic dilutions

Front 88

Spectrophmeter

Back 88

Used to determine turbidity.

Pass light through tubs, measure light

Front 89

Metabolic activity of the population

Back 89

Eyeballing how many organisms are there by thw metabolism it has undergone

Front 90

Dry weight

Back 90

Filamentous bacteria and molds.

Dehydrate organism and weigh it

Front 91

Symbiosis

Back 91

Relationship between 2 organisms

Front 92

Mutualism

Back 92

( + + )

Both benefit

Front 93

Commensalism

Back 93

( + 0 )

One benefits, other one doesn't either way

Front 94

Parasitism

Back 94

( + - )

One benefits, other is harmed