Microbial Nutrition, Ecology, And Growth

Front 1

Where do microbes get their nutrients from?

Back 1

The environment

Front 2

What are the macronutrients?

Back 2

The major elements:

-C, O, H, N, P, S

The minor elements:

-Mg2+, Ca2+, Fe2+, K+, Na+, Cl-

Front 3

What are micronutrients?

Back 3

Trace elements necessaryfor enzyme function

Front 4

What are the organisms that use carbon as nutrition source?

Back 4

Autotrophs & Hetertrophs

Front 5

Autotrophs derive their energy from what two sources?

Back 5

Sunlight and Chemical reactions

Front 6

What organisms obtain energy from organic molecules?

Back 6

Chemotrophs

Front 7

What organisms obtain energy from light?

Back 7

Phototrophs

Front 8

What organisms obtain energy from inorganic molecules?

Back 8

Lithotrophs

Front 9

Microorganisms require an energy source and a carbon source. Where can a microorganism get energy? Where can it get carbon? Where are the sources used by chemoautotrophs?

Back 9

Microorganisms can get their energy from organic molecules, light and inorganic molecules. They can get carbon from organic carbon (others) or inorganic carbon (themselves). Chemoautotrophs (or chemotrophic autotroph), in addition to deriving energy from chemical reactions, synthesize all necessary organic compounds from carbon dioxide. Chemoautotrophs use inorganic energy sources, such as hydrogen sulfide, elemental sulfur, ferrous iron, molecular hydrogen, and ammonia.

Front 10

What are Macronutrients?

Back 10

A substance required in relatively large amounts by living organisms, in particular.

Front 11

What are aerobes?

Back 11

A microorganism that grows in the presence of air or requires oxygen for growth.

Front 12

What are microaerophiles?

Back 12

Organisms that need oxygen because they cannot ferment or respire anaerobically.

However, they are poisoned by high concentrations of oxygen.

They gather in the upper part of the test tube but not the very top.

Front 13

What are anaerobes?

Back 13

An organism that grows without air, or requires oxygen-free conditions to live.

Front 14

What are Facultative anaerobes?

Back 14

Organisms that makes ATP by aerobic respiration if oxygen is present, but is capable of switching to fermentation or anaerobic respiration if oxygen is absent.

Front 15

What are Aerotolerant anaerobes?

Back 15

Organisms, which cannot use oxygen for growth, but tolerate its presence.

Front 16

What are acidophiles?

Back 16

Organisms are those that thrive under highly acidic conditions (usually at pH 2.0 or below).

Front 17

What are neutrophiles?

Back 17

Organisms that thrives in neutral pH environments.

Front 18

What are Alkaliphiles?

Back 18

Organisms that are capable of survival in alkaline (pH roughly 8.5–11) environments, growing optimally around a pH of 10.

Front 19

What are Barophiles?

Back 19

Organisms that metabolize or function better at high pressure than they do at atmospheric pressure.

Front 20

What are Osmophiles?

Back 20

Organisms adapted to environments with high osmotic pressures, such as high sugar concentrations.

Front 21

What are halophiles?

Back 21

Organisms that thrive in high salt concentrations.

Front 22

What are xerophiles?

Back 22

Organisms that can grow and reproduce in conditions with a low availability of water, also known as water activity.

Front 23

What is osmosis?

Back 23

Movement of water across a selectively permeable membranetowards the more concentrated side in an attempt to dilute downthat concentration.

Front 24

A bacterium living in a freshwater stream that is moved to saltyseawater would find itself in what tonicity? What would happen tothis cell after it is moved?

Back 24

The bacteria are being moved into a HYPERtonic solution. This is because they normally live in freshwater (with low salt levels), and they are being moved into salty water, which has lots of salt. Since the seawater has a HIGHER concentration of salt compared to the inside of the bacteria (since they are freshwater bacteria that are used to low levels of salt), the solution is hypertonic. The high levels of salt outside the bacterial cells will drain water out of the cells, causing them to shrivel up.

Front 25

Describe isotonic solutions in cells with cell walls?

Back 25

Water concentration is equal insideandoutside the cell, thus rates of diffusionare equal in both directions.

Front 26

Describe hypotonic solutions in cells with cell walls?

Back 26

Net diffusion of water is into the cell; thisswells the protoplast and pushes ittightlyagainst the wall. Wall usually preventscell from bursting.

The solute concentration of the external environment is lower than that of the cell's internal environment.

Front 27

Describe hypertonic solutions in cells with cell walls?

Back 27

Water diffuses out of the cell andshrinks the cell membrane awayfromthe cell wall; process is known asplasmolysis.

Front 28

Describe isotonic solutions in cells without cell walls?

Back 28

Rates of diffusion areequalin both directions.

Front 29

Describe hypotonic solutions in cells without cell walls?

Back 29

Diffusion of water into the cell causesit to swell, and may burst it if nomechanism exists to remove thewater.

Front 30

Describe hypotonic solutions in cells without cell walls?

Back 30

Water diffusing out of the cell causesit to shrink and become distorted.

Front 31

What is the polarity of most nutrients?

Back 31

Polar

Front 32

Why can't nutrients cross the membrane alone?

Back 32

Because most require nutrients or because they need move against the concentration gradient, which requires energy.

Front 33

What are the two forms of nutrient transport that do not require energy?

Back 33

Facilitied Diffusion and Passive/Simple Diffusion

Front 34

What are the two forms of nutrients transport that do require energy?

Back 34

Active Tranpost and Endocytosis

Front 35

What is Facilitated Diffusion?

Back 35

Transport of nutrients that does not require energy because it is moving down the concentration gradient. It utilizes a carrier protein that will bind with a specific substance. When the substance binds, the conformation of the carrier proteins change so that substance is moved across the membrane. This mode of transportation is used to transport hydrophilic (polar) molecules because the tails of the phospholipid boiler are hydrophilic.

Front 36

What is Passive /SimpleDiffusion?

Back 36

Transport of nutrients that does not require energy because it is moving down the concentration gradient.

Front 37

What is Active Transport?

Back 37

Transport of nutrients that does require energy because it is moving against the concentration gradient, from low concentrations to high concentrations. It utilizes a carrier protein that will bind with a specific substance. When the substance binds, the conformation of the carrier proteins change so that substance is moved across the membrane. Group translocation modifies the substrate.

Front 38

What is group translocation?

Back 38

A process that can move solutes from a low to a high concentration environment, requires a number of proteins (cytoplamic and membrane), chemical energy in the form of phosphoenolpyruvate (PEP) is reqired, and molecule is modified (phosphorylated by PEP) as it moves across membrane. Used to transport sugars.

Front 39

What is endocytosis?

Back 39

Phagocytosis +Pinocytosis

The cell forms a vesicle to surround and engulf a nutrient and the nutrient is dissolved in water inside the vesicle, allowing whole protiens (like immunoglobulin from breast milk) to be absorbed intact.

Front 40

If required by at least one of the organisms, therelationship between two organisms that live close toeach other and share nutrients is called___________________________.

Back 40

Symbiotic

Front 41

What are the 3 forms that organisms that live in close narrational relationships take?

Back 41

Mutualism, Commensalism, and Parasitism

Front 42

Define Mutualism

Back 42

Obligatory dependent; both members benefit. Example: Oxpeckers and zebras or rhinos - In this relationship, the oxpecker (a bird) lives on the zebra or rhino, sustaining itself by eating all of the bugs and parasites on the animal.

Front 43

Define Commensalism

Back 43

The commensal benefits; other member not harmed. Example: Cattle Egret and Livestock - This bird moves about in the pastures, and follows livestock such as cattle and horses. The cattle egret eats up the insects hiding under vegetation close to the grounds, which get stirred up when the cattle walk through them.

Front 44

Define Parasitism

Back 44

Parasite is dependent and benefits; host harmed. Example: Tapeworms are segmented flatworms that attach themselves to the insides of the intestines of animals such as cows, pigs, and humans. They get food by eating the host's partly digested food, depriving the host of nutrients.

Front 45

What is a psyhcrophile?

Back 45

An organism that thrives at cold temperatures. Its optimum temperature is below 15C and is capable of growth at 0C

Front 46

What is a mesophile?

Back 46

An organism that thrives at moderate temperatures. Its optimum temperature range is 20C-40C.

Front 47

What is a thermophile?

Back 47

An organism that thrives at high temperature. Its optimum temperature is greater than 45C.

Front 48

What are biofilms?

Back 48

Most biofilms are mixed cultures of microbes, that is bound to a surface. It is initiated by a prisoner colonizer then other microbes attach to those bacteria or to the polymeric sugar and protein substances that are inevitably secreted by the microbial colonizers on the surface.

Front 49

How do bacterial cells divide/multiple?

Back 49

Through binary fission

Front 50

What are the steps of Binary Fission?

Back 50

1. Parent cell enlarges

2. Chromosomes are duplicated

3. Protein band that resemble actin and tubulin forms in the in the center of the cell, pulling the cell envelope together

4. Septum formation begins

5. When septum formation is complete, cells are considered divided.

Front 51

What is referred to as the generation or doubling time?

Back 51

The time required for a complete fission cycle

Front 52

Is binary fission asexual or sexual reproduction?

Back 52

Asexual reproduciton

Front 53

By how much does the new fission cycle or generation increase the population by?

Back 53

By a factor of 2 or doubles it.

Front 54

What is a bacterial growth curve?

Back 54

A curve on a graph that shows the changes in size of a bacterial population over time in a culture.

Front 55

What are the stages in the bacterial growth curve?

Back 55

1. Lag phase

2. Exponential growth phase

3. Stationary phase

4. Death phase

Front 56

Describe the lag phase

Back 56

The relatively "flat" period on the graph when the population appears not to be growing or is growing at less than the exponential rate.

Front 57

What are the primary reasons for growth lags?

Back 57

1. the newly inoculated cells require a period of adjustment, enlargement, and synthesis

2. the cells are not yet multiplying at their maximum rate

3. the population of cells is so sparse or dilute that the sampling misses them

*stil metabolically active*

Front 58

Describe the exponential growth phase

Back 58

When the cells reach maximum rate of cell division. This phase will continue as long as cells have adequate nutrients and the environment is favorable.

Front 59

Describe the stationary growth phase

Back 59

The population enters the survival mode in which cells stop growing or grow slowly due to depleted nutrients and oxygen plus excretion of organic acids and other biochemical pollutants into the growth medium, due to the increased density of cells.

Front 60

Describe the death phase

Back 60

As the limiting factors intensify, cells begin to die at an exponential rate (literally perishing in their own waste) and they are unable to multiply.

Front 61

The source of the necessary elements of life is?

Back 61

An inorganic environmental reservoir.

Front 62

An organism that can synthesize all its require organic components from CO2 using energy from the sun is a ________?

Back 62

Photoautotroph

Front 63

Chemoautotrohps can survive on ____ alone?

Back 63

Minerals and CO2

Front 64

Which is the following statements is true for all organisms?

a. They require organic nutrients

b. They require inorganic nutrients

c. They require growth factors

d. They require oxygen gas

Back 64

c. They require growth factors

Front 65

A pathogen would most accurate be described as a ______?

Back 65

Parasite

Front 66

Which of the following is true of passive transport?

a. It requires a gradient

b. It uses the cell wall

c. It includes endocytosis

d. It only moves water

Back 66

a. It requires a gradient

Front 67

A cell exposed to hypertonic environment will ______ by osmosis.

Back 67

lose water

Front 68

Psychrophiles would be expected to grow where?

a. in hot springs

b. on the human body

c. at refrigeration temperatures

d. at low pH

Back 68

c. at refrigeration temperatures

Front 69

Superoxide ion is toxic to strict anaerobes because they lack _____?

Back 69

dismustase

Front 70

In a viable plate count, each ____ represents a ____ from the sample population.

Back 70

colony, cell

Front 71

True or False: Active transport of a substance across a membrane requires a concentration gradient.

Back 71

False; Active transport of a substance across a membrane requires energy.

Front 72

True or False: An organic nutrient essential to an organism's metabolism that it cannot synthesize is called factor.

Back 72

True

Front 73

True or False: Biofilms often consists of multiple species of bacteria.

Back 73

True

Front 74

True or False: An obligate halophile is an organism that requires high osmotic pressure.

Back 74

False; An obligate halophile is an organism that requires high salt concentration.

Front 75

True or False: An anaerobe can grow with out without oxygen.

Back 75

False; A facultative anaerobe can grow with or without oxygen

Front 76

Where are nutrients used?

Back 76

In cellular activities such as metabolism and growth.

Front 77

What are heterotrophs?

Back 77

Organisms that must obtain its carbon in an organic form. Because organic carbon originates from the bodies of other organism, heterotrophs are depended on other life forms.

Front 78

What are autotrophs?

Back 78

Organisms that use inorganic CO2 as it carbon source and convert CO2 into organic compounds, they are not nutritionally dependent on other living things.

Front 79

List all the possibleoptima groupings for anorganism you havedetermined grows best onpH 5 medium high in salt,at 650 C, in a sealedchamber.

Back 79

1. Alkaliphile

2. halophile

3. Thermophile

4. Anaerobe

Front 80

What is an photoautotroph?

Back 80

An organisms who's energy source is sunlight, here photosynthetic. They capture the energy of life rays and transform it intro chemical energy that can be used in cell metabolism.

Front 81

What are the two types of chemoautotrophs?

Back 81

Chemoorganic autotrophs and Lithoautotrophs

Front 82

What are Chemoorganic autotrophs?

Back 82

Organisms that use organic compounds for energy and inorganic compounds as a carbon source.

Front 83

What are Lithoautotrophs?

Back 83

Organisms that require neither sunlight nor organic nutrients, relying totally on inorganic minerals.

Front 84

What are chemoheterotrophs?

Back 84

Organisms that derive both their carbon and energy from organic compounds.

Front 85

What are saprobes?

Back 85

Organisms that act as decomposers, feeding on dead and decaying wood, leaves, litter, and other organic matter.

Front 86

What structure in the cell is specialized for transport?

Back 86

The cell membrane

Front 87

As temperature increases the molecular movement becomes faster this is called?

Back 87

Thermal movement

Front 88

What determines the diffusion of molecules across the cell membrane?

Back 88

Permeability of the membrane and the concentraton gradient

Front 89

What provides the most hypotonic environment for cells?

Back 89

Pure water because it has no solute.

Front 90

Why is a slight favorable hypotonic environment be favorable for a cell?

Back 90

The constant slight tendency for water to flow into the cell keeps the cell membrane fully extended and they cytoplasm full.

Optimum condition for many processes occurring in and on the membrane.

Front 91

What is simple diffusion limited to?

Back 91

Small, non-polar molecules and ions that can pass through the membrane

Front 92

Carrier proteins exhibit what?

Back 92

Specificity, meaning they bind and transport only one or few types of molecules

Saturation, all of the transporters bindings sites are occupied

and

Competition, when two molecules of similar shape can bind to the same binding site on carrier protein (The chemical with the higher binding affinity or the chemical in the higher concentration, will be transported at a greater rate.)

Front 93

What atmospheric gases influence microbial growth the most?

Back 93

O2 and CO2