Microbiology Unit 2

Front 1

What is the process by which chemical

substances called nutrients are acquired from the environment and are used for growth and metabolism?

Back 1

Nutrition

Front 2

Nutrients that are essential to life and survival are called what?

Back 2

Essential Nutrients

Front 3

What are the nutrients required in large amounts that play key roles in metabolism and cell structure and list the four examples

Back 3

Macronutrients

1. Oxygen

2. Hydrogen

3. Carbon

4. Nitrogen

Front 4

What are the nutrients that are required in small amounts? Also known as the trace elements. List examples

Back 4

Micronutrients

Zn, Fe, Mg, Mn, Co, Ca, ect.

Front 5

What are nutrients that contain no carbon?

Back 5

Inorganic Nutrients

Front 6

What are the nutrients that contain carbon?

Back 6

Organic Nutrients

Front 7

What is the nutritional analysis of a microbe?

Back 7

1. Water- 70-80% of a bacterial cell

2. proteins- 2nd in abundance

3. inorganic nutrients- trace elements

4. organic nutrients- carbohydrates, lipids, and proteins

Front 8

Which microbes obtain their carbon from inorganic sources? (Known to get their carbon from CO2)

Back 8

Autotrophs

Front 9

Which microbes obtain their carbon from

organic sources? (Known to get their carbon from carbohydrates, lipids, and proteins)

Back 9

Heterotrophs

Front 10

Where do microbes obtain their Hydrogen,

Oxygen, and Nitrogen?

Back 10

It's abundantly available in gases from the

environment; may be obtained from biological macromolecules

Front 11

Where do microbes obtain their phosphorous?

Back 11

Obtained as inorganic phosphate; phosphorus is often obtained rock and ocean deposits

Front 12

Where do microbes obtain their Sulfur?

Back 12

Obtained as sulfates or it is sometimes found in its mineral form; forms of sulfur can also be found dissolved in H2O

Front 13

Where do microbes obtain other nutrients?

Back 13

The trace elements are often found in their

mineral form

Front 14

What are organic compounds such as certain amino acids and vitamins that CANNOT be

synthesized by a microorganism and thus must be provided as a nutrient?

Back 14

Growth Factors

Front 15

What are bacteria that utilize inorganic sources of carbon (CO2) called?

Back 15

Autotrophs

Front 16

What are bacteria that use sunlight as their

energy source and CO2 as their carbon source called? Ex. cyanobacteria species

Back 16

Photoautotroph

Front 17

What are bacteria that use inorganic chemical

reactions as their energy source and CO2 as their carbon source called?

Back 17

Chemoautotrophs also known as chemolithotrophs

Front 18

Which bacteria must obtain their carbon from organic sources?

Back 18

Heterotrophs

Front 19

What are bacteria that use sunlight as their

energy source and organic nutrients like

carbohydrates, lipids, and proteins as their

carbon source called?

Back 19

Photoheterotrophs

Front 20

What are bacteria that use organic chemical

reactions as their energy source and use organic carbon sources as their carbon source called? (Use carbohydrates, lipids, and proteins as both the source of energy and carbon)

Back 20

Chemoheterotrophs

Front 21

What are free living microorganisms that feed on organic debris from dead organisms called? (These include both bacteria and Fungi)

Back 21

Saprobe/saprophyte

Front 22

What is an organism that derives nutrients from cells or tissues from a living thing called?

(e.g. intestinal worms, ect.)

Back 22

Parasite

Front 23

What type of parasite lives on the body of

another living organism?

(e.g. lice or fleas)

Back 23

Ectoparasite

Front 24

What type of parasite lives inside the body in

organs or tissues?

Back 24

Endoparasite

Front 25

What type of parasite lives within cells?

(e.g. the protozoan that causes malaria lives within human red blood cells and liver cells; Chlamydia caused by bacteria species that lives within host cells)

Back 25

Intracellular

Front 26

What is simple (passive) diffusion?

Back 26

The movement of atoms down a concentration gradient with no energy input. (Hi to Lo)

Front 27

What can move freely across a cell membrane using simple diffusion?

Back 27

Small, non polar, non-ionic molecules

(CO2, O2, N2, some small sugars, and some H2O)

Front 28

What is Osmosis?

Back 28

The diffusion of water through a membrane

Front 29

What is Tonicity?

Back 29

The relative concentration of solutes (usually

dissolved salts) in two fluids. (for example:

extracellular fluid and cytoplasmic fluid)

Front 30

Which tonicity has the same concentration of solutes both inside and outside of the cell?

Back 30

Isotonic Solution

Front 31

Which tonicity has a greater concentration of solutes outside the cell than inside the cell?

Back 31

Hypertonic Solution

Front 32

When a cell is placed in a hypertonic solution the water will move out of the cell causing it to shrink, what is this called?

Back 32

Plasmolysis

Front 33

Which solution has a greater concentration of solutes inside the cell than outside?

Back 33

Hypotonic Solution

Front 34

When a cell is placed in a hypotonic solution,

water will move into the cell and the cell will

eventually burst, what is this called?

Back 34

Plasmoptysis or simply lysis

Front 35

What is facilitated diffusion?

Back 35

A form of passive transport that requires a

concentration gradient, a carrier or channel

protein but NO energy input.

Front 36

What is active transport?

Back 36

Movement of solutes against a concentration gradient. This requires energy input. (Lo to Hi)

"moving uphill"

Front 37

What is Endocytosis?

Back 37

A type of bulk transport that requires energy to bring substances in the cell through a vesicle or phagosome.

Front 38

What is Exocytosis?

Back 38

A type of bulk transport that requires energy to push substances out of the cell by forming a vesicle or phagosome.

Front 39

What is phagocytosis?

Back 39

Cell eating

Front 40

What is pinocytosis?

Back 40

Cell drinking

Front 41

What is the lowest temperature at which growth and metabolism can proceed called?

Back 41

Minimum Temperature

(Bacteria do not generally die when placed

below the minimum temp, they just slow.)

Front 42

What is the highest temperature at which growth and metabolism will proceed?

Back 42

Maximum Temperature

(Cells are often killed when maximum temp is exceeded)

Front 43

What is the temperature range that promotes the fastest rate of growth and metabolism?

Back 43

Optimum Temperature

Front 44

What is the classification of a cold loving

microbe and what are the temperatures?

Back 44

Psychrophile

(Min= 0C, Max= 20C, Optimum= <15C usually 8C)

Front 45

What is the classification of a median/middle

loving microbe and what are the temperatures?

Back 45

Mesophile

(Min= 20C, Max= 40C, Optimum is between the max and min usually 37C)

Front 46

What is the classification of a heat loving microbe and what are the temperatures?

Back 46

Thermophile

(Min= 45C, Max=85C, Optimum= 55C)

Front 47

What are the 3 gases that profoundly affect

bacteria?

Back 47

O2, CO2, N2

Front 48

What is an Aerobe?

Back 48

capable of using oxygen gas in metabolism AND capable of processing toxic oxygen metabolic

byproducts.

Front 49

Which type of microbe must have O2 for survival?

Back 49

Obligate aerobe

(These microorganisms use oxygen as the terminal electron acceptor in respiration)

Front 50

Which type of microbe does not absolutely need O2 to grow but does grow better in its presence?

Back 50

Facultative Anaerobe

Front 51

What is an Anaerobe?

Back 51

Microorganisms that completely lack the

metabolic machinery needed to utilize O2.

Front 52

Which type of microbe cannot tolerate any O2 at all?

Back 52

Obligate (strict) Anaerobe

(They lack enzymes to process toxic oxygen

byproducts)

Front 53

Which type of microbe cannot metabolically

utilize O2 but can grow and survive in its

presence?

Back 53

Facultative Aerobe (aerotolerant anaerobe)

Front 54

Which type of microbe prefer decreased amounts of O2 (compared to normal

atmospheric levels)?

Back 54

Microaerophile

Front 55

Which type of microbe prefer increased amounts of CO2 (higher than normally present in the

atmosphere)?

Back 55

Capnophile

(prefer 3-10%)

Front 56

Killing of anaerobes is due to the accumulation of toxic metabolic byproducts of oxygen

including ______, ________, and _________ radicals.

Back 56

Superoxide, Hydrogen Peroxide, and Hydroxyl radicals.

Front 57

Microbes, which can grow in the presence of

oxygen, produce an enzyme called ____________, which converts superoxide into hydrogen

peroxide. Anaerobes lack this enzyme.

Back 57

Superoxide Dismutase (SOD)

Front 58

Hydrogen Peroxide is also toxic to microbes; many microbes which grow in the presence of oxygen have the enzymes ________ or ________ which breaks down hydrogen peroxide into

water and oxygen. Obligate anaerobes also lack these enzymes.

Back 58

Catalase or Peroxidase

Front 59

What is the equation for superoxide dismutase?

Back 59

2 O2- + 2 H+ -------------> H2O2 + O2

Front 60

What is the equation for catalase?

Back 60

2 H2O2 ---------> 2 H2O + O2

Front 61

On the pH scale what is acidic and what is basic?

Back 61

0-6.99 Acidic

7 neutral

7.01-14 Basic

Front 62

Which type of microbe have a growth optimum between 0-5.5?

Back 62

Acidophiles

Front 63

Which microbes must have an acidic

environment for survival?

Back 63

Obligate Acidophile

(prefers a pH of 1-2)

Front 64

Which microbes have a growth optimum

between pH 5.5-8.0?

Back 64

Neutrophiles

Front 65

Are human pathogenic bacteria acidophiles,

neutrophiles, or alkalinophiles?

Back 65

Neutrophiles

Front 66

Which microbes have a growth optimum

between pH 8-11.5?

Back 66

Alkalinophiles

Front 67

Which microbes must have a basic environment for life?

Back 67

Obligate alkalinophiles

Front 68

Which microbes prefer a salty environment?

Back 68

Halophiles

Front 69

What do all living things, including

microorganisms, require for growth, repair, and metabolism?

Back 69

Water

Front 70

What do photoautotrophs and

photoheterotrophs require as light energy from the sun?

Back 70

Radiation

Front 71

________ are bacteria that are adapted to live at the deepest ocean depths, which supplies them with extreme pressures they require.

Back 71

Barophiles

Front 72

What are the 3 miscellaneous environmental

factors?

Back 72

1. Water

2. Radiation

3. Hydrostatic Pressure

Front 73

__________ relationships- Organisms live in a close nutritional relationship that is required by one or more members involved in the relationship.

Back 73

Symbiotic Relationships

Front 74

What type of symbiotic relationship is an

obligate/dependent relationship where both members benefit?

Back 74

Mutualism

Front 75

What type of symbiotic relationship benefits the commensal and does not harm the other

member?

Back 75

Commensalism

Front 76

What type of symbiotic relationship has a host organism that provides the dependent parasitic organism with both a habitat and nutrients; the host is harmed?

Back 76

Parasitism

Front 77

___________ relationship- All organisms are free living and the relationships are not necessary for survival.

Back 77

Non-symbiotic Relationships

Front 78

In which type of non-symbiotic relationship do the members cooperate and share benefits?

Back 78

Synergism

(ex. soil bacteria and plant roots- the plants

provide the bacteria with necessary growth

factors, and the bacteria help fertilize the plant by suppling it with minerals)

Front 79

In which type of non-symbiotic relationship are some members inhibited or destroyed by

others?

Back 79

Antagonism

Front 80

__________ _____________ is the process by which one bacterial cell divides to become two

bacterial cells.

Back 80

Binary Fission

Front 81

What is bacterial growth?

Back 81

Bacterial Growth is usually defined in terms of an increase in cell number.

Front 82

What is a bacterial colony?

Back 82

A colony is a circular, raised, or flattened mass of millions of bacterial cells which are the progeny of a single, original bacterial cell; therefore, one colony = one original bacterial cell or CFU (colony forming unit)

Front 83

What is bacterial growth limited by?

Back 83

Nutrient availability

Metabolic waste accumulation

Front 84

What are the 4 stages of the Normal Microbial Growth Curve?

Back 84

1. Lag Phase

2. Exponential Phase

3. Stationary Phase

4.Death Phase

Front 85

Explain what occurs during the lag phase.

Back 85

-Zero bacterial growth

-Cells depleted of metabolites and enzymes

begin to adjust to the new growth medium

-Cell begins to divide

-The beginning of binary fission marks the onset of the next phase, the exponential phase

Front 86

Explain what occurs during the Exponential Phase?

Back 86

-Marked by a period when the cells steadily

divide at a constant growth rate

-The log of the # of cells plotted against time

results in a straight line

-Marks the period when growth rate is at a

maximum

-Continues until either the medium becomes exhausted of its nutrients or toxic metabolic byproducts build up in the medium, which inhibit

further growth

Front 87

How fast do bacteria grow?

Back 87

Under optimum conditions, the average generation time for bacteria is 30-60 minutes.

Front 88

Explain what occurs during the stationary

phase.

Back 88

-The rate of cell division= the rate of cell death

-Continue to divide; however, for each new cell produced, one dies

Front 89

What are the causes of the stationary phase?

Back 89

1. Nutrient Exhaustion

2. Excretion of organic acids, which lower pH, causing the bacteria to begin to die.

Front 90

What are the characteristics of the stationary phase?

Back 90

1. There tends to be variable staining. The results of the gram stain are absurd because of the age of the cell wall.

2. The bacteria tend to be resistant to toxic agents, including antibiotics and chemicals.

3. If the bacteria are of the genera Bacillus or Clostridium the sporulation process is carried out

Front 91

Explain what occurs in the Death Phase.

Back 91

The death rate is marked by a negative growth rate. (more cells are dying than are being

produced)

Front 92

What are the time intervals between the stages of microbial growth called?

Back 92

Transitional periods

Front 93

Why is studying a microbial growth curve useful?

Back 93

To help determine if an antibiotic is

bacteriostatic (inhibits new growth) or

bacteriocidal (one that kills bacteria).

Front 94

What is the Microbial Growth Equation?

Back 94

Nf=2^x(n)

Nf= final # of cells

x= # of generations

n= original # of cells

Front 95

What are the nutrient substances on which

bacteria are grown in a laboratory setting called?

Back 95

Media

Front 96

What are the 3 physical states of media?

Back 96

1. liquid- broths

2. semisolid- used in determining motility of some cultures

3. solid- contains agar

Front 97

A ________ __________ of bacterium is one which contains only one species.

Back 97

Pure Culture

Front 98

What is Gelatin?

Back 98

Early on, gelatin was used to solidify

bacteriological culture media. Unfortunately, gelatin is a protein and is readily solubilized by the action of bacterial hydrolytic enzymes. Thus, gelatin is now infrequently used as a solidifying agent when one wants to demonstrate gelatin hydrolysis as a step in the identification of a

specific bacterium.

Front 99

What is Agar?

Back 99

The most often used solidifying agent. Agar is a complex polysaccharide derived from marine red algae. Most bacteria lack the enzymes to

digest agar.

Front 100

Agar dissolves (into solution) at ______ degrees Celsius and solidifies at about ____ degrees

Celsius. Bacterial cells can be suspended in ____ degrees celsius agar without damage to the cells.

Back 100

100, 42, 45

Front 101

What is synthetic (defined) media?

Back 101

Media with chemically defined explicitly and

explicitly specified compositions. Such media contain pure chemical nutrients that vary little from one source to another and have molecular content specified by means of an exact formula. Such media has every ingredient well-defined, and such media are standardized and

reproducible for the cases of research and cell culture.

Front 102

What is non synthetic (complex) media?

Back 102

For a nonsynthetic medium, at least one

component is not chemically defined. This type of medium cannot be represented by an exact chemical formula.

Front 103

Which media is designed to grow a broad

spectrum of bacteria that do not have special growth requirements?

Back 103

General purpose media

Front 104

General Purpose media is non-inhibitory, which means what?

Back 104

Something like TSA doesn't prevent anything from growing. rather it promotes non-inhibited growth.

Front 105

Which media is an enriched medium that contains the basic nutrients to which additives such as blood, serum, or animal tissue extracts?

Back 105

Enriched Media

Front 106

What are two examples of Enriched Media?

Back 106

1. Blood agar- Blood agar is made from tryptic soy agar which is amended with 5% defibrinated sheep blood.

2. Chocolate agar- made from tryptic soy agar in which lysed blood cells is added.

Front 107

Which media is one which contains certain chemical substances which will permit the growth of one group of bacteria while inhibiting the growth of others?

Back 107

Selective Media

Front 108

Give 2 examples of Selective Media.

Back 108

1. Columbia CNA agar- contains antibiotics which permit the growth of gram (+) cocci while inhibiting the growth of gram (-) bacteria.

2. SS Agar

Front 109

Which type of media is one which permits a kind of growth or change that allows the observer to differentiate between types of bacteria?

Back 109

Differential Media

Front 110

Give 3 examples of Differential Media.

Back 110

1. MacConkey (MAC) Agar

2. Mannitol Salt Agar (MSA)

3. Blood Agar

Front 111

What are the 3 types of hemolytic reactions on blood agar and how are they different?

Back 111

1. Beta hemolysis- Characterized by the

complete break down of red blood cells around the bacterial colony and results in a "zone of clearing"

2. Alpha hemolysis- Marked by an incomplete hemolysis and manifests itself in a "greening" reaction where a greenish color appears around the colony

3. Gamma hemolysis- a misnomer and actually is marked by no hemolysis of any kind around the colony.

Front 112

Which type of media is a highly selective medium (also highly inhibitory) that only allows very specific organisms to grow?

Back 112

Enrichment Media

Front 113

Which type of media is a miscellaneous media that contains a substance that absorbs oxygen or slows the penetration of oxygen in a medium, thus reducing its availability.

Back 113

Reducing Media

Front 114

Which type of media is used to maintain and preserve specimens that have to be held for a period of time before clinical analysis or to

sustain delicate species that die rapidly if not held under stable conditions?

Back 114

Transport Media

Front 115

List 2 examples of transport media.

Back 115

1. Stuart's

2. Amie's

(both of these contain buffers and absorbents to prevent cell destruction, but neither will support growth. These media are simply for holding the cells until they can be streaked onto culture

media)

Front 116

What is culturing?

Back 116

Obtaining the specimen

Front 117

What is inoculation?

Back 117

Placing ("planting") the obtained specimen in or on the appropriate culture media

Front 118

What is incubation?

Back 118

Placing a culture in an appropriate environment

(e.g.. aerobic vs anaerobic conditions, temp)

Front 119

What is a culture?

Back 119

Observable growth in or on the media

Front 120

What is a pure culture?

Back 120

Only one type of bacteria is present. All colonies present originated from a single bacterial cell. Theoretically, cultures will be isolated in a pure culture, meaning they are not touching other colonies.

Front 121

What is a mixed culture?

Back 121

The culture contains two or more organisms. This can be based on the presence of multiple types of colonies.

Front 122

What is a contaminated culture?

Back 122

The culture contains unwanted bacteria.

(If you find you have a contaminated culture, it is sometimes necessary to use a selective and/or differential medium to isolate specific bacteria)

Front 123

What are the two ways to obtain a pure culture and how are they different?

Back 123

1. Streak Plate- most commonly used. The principle behind the streak plate for isolation is one of continuing dilution until a single cell coms to rest at a locus on the plate. Thus, this single bacteria cell will undergo binary fission to give rise to a colony composed of millions of cells. All the cells comprising the colony should be of a single species.

2. Pour Plate- Another commonly used method of obtaining a pure culture. Isolate colonies, however, are not as easily obtained with this method.

Front 124

What is chromogenesis?

Back 124

Some bacteria have the genetic ability to produce a pigment on growth media. The bacteria have a gene on their chromosome to produce a colored colony.