Chap 7 Micro Nutrition and Growth Flashcards

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1
Q

Essential Nutrients

A

carbon,hydrogen, oxygen,nitrogen, phosphorus(phosphate), and sulfur
-CHONPS

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2
Q

Two categories of essential nutrients

A

-Macronutrients
-Micronutrients

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3
Q

Macronutrients

A

-Required in large quantities
-Play role in cell structure and metabolism
-Examples: Carbon, hydrogen and oxygen

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4
Q

Micronutrients/trace elements

A

-Used in smaller amounts
-Involved in enzyme function and protein structure
-Examples: maganese, sinc and nickel

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5
Q

inorganic nutrient

A

-An atom or simple molecule that contains a combination of atoms other than carbon and hydrogen
-Metal, salts, gases and water

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6
Q

Organic nutrient

A

-Contain carbon and hydrogen atoms
-Usually the product of living beings

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7
Q

heterotrophs

A

-Organism that must obtain it’s nutrients from an organic form (living thing)

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8
Q

Autotroph

A

-Self feeder
-uses inorganic CO2 as it’s carbon source
-converts CO2 into organic compounds

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9
Q

Nitrogen sources

A

-Nitrogen gas makes up 79% of the Earth atmosphere
-DNA, RNA, ATP are the primary Nitrogen source for heterotrophs

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10
Q

Oxygen sources

A

-Free gaseous oxygen (O2) makes up 20% of the atmosphere

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11
Q

Hydrogen sources

A

-Hydrogen is a major element in all organic and several inorganic compounds
-Critical for maintaining pH, forming hydrogen bonds, and source of free energy in oxidation reduction reactions in respiration

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12
Q

Phosphorus/Phosphate sources

A

-Main inorganic source of phosphorus is phosphate found in rocks and oceanic mineral deposits
-Key component of nucleic acids and therefore essential to the genetics of cells and viruses

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13
Q

Sulfer sources

A

-Distributed through the environment in mineral form
-Essential component of some vitamins and amino acids methionine and cysteine

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14
Q

Phototrophs

A

-Microbes that gain energy from sunlight or visible light rays (photosynthesize)

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15
Q

Chemotrophs

A

-Microbes that gain energy from chemical compounds

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16
Q

Photoautotrophs

A

-Photosynthetic autotrophs that capture energy of light rays and transform it into chemical energy that can be used in cell metabolism

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17
Q

The two types of Chemoautotrophs

A

-Chemoorganic autotrophs and chemolithoautotrophs

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18
Q

Chemoorganic autotrophs

A

-Use organic compounds for energy and inorganic compounds as a carbon source

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19
Q

Chemolithoautotrophs

A

-Require neither sunlight nor organic nutrients.
-Rely on inorganic materials
-Remove electrons from inorganic substrates and combines them with carbon dioxide and hydrogen

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20
Q

Methanogens

A

-A type of chemoorganic autotroph (Archaea) which produces methane (CH4) from hydrogen gas and carbon dioxide

4H2 + CO2 –> CH4 + H2O

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21
Q

Chemoheterotrophs/ what are the two types

A

-Derive both carbon and energy from organic compounds
-Saprobes
-Parasites

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22
Q

aerobic respiration

A

-process of cellular respiration that takes place in the presence of oxygen gas to produce energy from food.

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23
Q

Saprobes

A

-Free-living microbe that feed on organic detritus from dead organisms

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24
Q

Parasite

A

-Feed on cells or tissues of a living host

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25
Q

Diffusion

A

-Molecular movement of atoms or molecules moving in a gradient from an area of higher density or concentration to an area of lower density or concentration
-Higher to lower!

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26
Q

Osmosis

A

Diffusion of water through a selectively permeable membrane

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27
Q

Isotonic

A

-External environment equal in solute concentration to the cells internal environment

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28
Q

Hypotonic

A

-Hypo means less
-External solute concentration is lower than the cells internal concentration
-Osmosis direction moves INTO the cell

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29
Q

Hypertonic

A

-Hyper means more
-External solute concentration higher than inside the cell
-Osmosis direction moves out of the cell

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30
Q

Passive/ simple diffusion

A

-Movement of particles from high to low concentration without a protein

31
Q

Active transport

A

-Uses energy
-Transports nutrients against diffution gradient or same direction but faster than diffusion alone
-Specific membrane proteins(permeases and pumps)
-Specialized pumps carry ions (K+, Na+ and H+) across membrane

32
Q

Facilitated diffusion

A

-No energy used.
-Molecule binds to specific receptor in the direction of higher to lower concentration

33
Q

Carrier mediated transport

A

-Active transport
-Atoms or molecules pumped into or out of cell by receptors
-Driven by ATP

34
Q

Group translocation

A

-Active transport
-Uses ATP
-Molecule moved across membrane and converted to useful substance

35
Q

Endocytosis

A

-Active transport
-Uses ATP
-Transport of large particles, cells and liquids by engulfment and vesicle formation

36
Q

Phagocytosis

A

-A type of endocytosis that moves solids into cells

37
Q

Pinocytosis

A

-A type of endocytosis that moves liquids into cell

38
Q

Environmental factors that influence microbes

A

-Heat - cold - gases -acid -radiation
-osmotic pressure - hydrostatic pressure and - other microbes

39
Q

Range of temps for the growth of a given microbial species

A

-Minimum temp
-Maximum temp
-Optimum temp

40
Q

Psychrophiles

A

-Organisms that have an optimum temp of 15C (59F)
-Growth at 0C (32F)
-Can not grow above 20C (68F)

Psychrotolerant optimum temps 15-30C (59-86F

41
Q

Mesophiles

A

-Majority of medically significant organisms
-Individual species can grow 10-50C ( 50-122F)
-Optimum growth 20-40C (68-104F)
-Most human pathogens 30-40 C

42
Q

Thermoduric microbes / Mesophile

A

-Microbes survive short exposure to high temps
-Common contaminants of heated or pasteurized foods

43
Q

Thermophiles

A

-Grow optimally at temps above 45C (113F)
-Live in soil and water associated with volcanic activity, compost piles, habitats exposed to sun
-General range of growth: 45C-80C (113-176F)
-Extreame thermophiles grow: 80C-121C

44
Q

Microbes fall into one of the three categories in how it uses oxygen

A

-Use oxygen and can detoxify it
-Can neither use oxygen nor detoxify it
-Do not use oxygen but can detoxify it

45
Q

Aerobe (aerobic organism)

A

-Can use gaseous oxygen in its metabolism
-Possesses enzymes needed to process toxic oxygen products

46
Q

Obligate aerobic organism

A

-Cannot grow without oxygen

47
Q

Facultative anaerobe

A

-Does not require oxygen for its metabolism
-Capable of growth in absence of oxygen
-Metabolizes by aerobic respiration when oxygen is present
-Adopts anaerobic metabolism (fermentation) when oxygen is absent

48
Q

Anaerobe (anaerobic organism)

A

-Lacks the metabolic enzyme systems for using oxygen in respiration

49
Q

Obligate anaerobes

A

-cannot tolerate free oxygen and will die in its presence
Live in highly reduced habitats such as deep muds, lakes, oceans, and soil

50
Q

pH

A

-the degree of acidity or alkalinity of a solution
-Expressed on a scale from 0 to 14
-Pure water is neutral at pH 7.0
-pH value decreases toward 0, acidity increases
-pH value increases toward 14, alkalinity increases

51
Q

obligate acidophiles

A

-Require an acidic environment for growth
-Molds and yeasts tolerate acid and are common spoilage agents of pickled foods

52
Q

Alkalinophiles

A

-Live in hot pools and soils that contain high levels of basic minerals
-Bacteria that decompose urine create alkaline conditions

53
Q

Osmophiles

A

-Live in habitats with high solute concentration

54
Q

Halophiles (Obligate Halophiles)

A

-Require high concentrations of salt for growth (9 to 25% NaCl)
-Have significant modifications to their cell walls and membranes and will lyse in hypotonic habitats

55
Q

Facultative halophiles

A

-Resistant to salt, even though they do not normally reside in high-salt environments

56
Q

Barophiles

A

-Deep sea microbes that exist in pressures up to 1000 times atmospheric pressure
-strictly adapted to high pressures that they rupture when exposed to normal atmospheric pressure

57
Q

Protective measures phototrophs and other microbes can use to protect against radiation/light

A

-Yellow carotenoid pigments absorb and dismantle toxic oxygen
-Some microbes use enzymes to overcome the damaging effects of UV radiation on DNA

58
Q

Symbiotic and its types

A

-Organisms live in close nutritional relationships
*Mutualism: both members benefit
*Commensalism: one benefits, other is not harmed
*Parasite is dependent and host is harmed

59
Q

Nonsymbiotic and it’s types

A

-Organisms are free living; relationships not required for survival
*Synergism: Members cooperate and share nutrients
*Antagonism: Some members are inhibited or destroyed by others

60
Q

Biofilms: epitome of synergy

A

-mixed communities of different kinds of bacteria and other microbes:
-“Pioneer” colonizer initially attaches to a surface
-Other microbes attach to the pioneer or to the polymeric or the polymeric sugar and protein substance secreted by the pioneer
-Monitors growth w/ Quorum sensing

61
Q

Quorum sensing

A

-cells are stimulated to release chemicals as the population grows to monitor its size

62
Q

Binary fission

A

-How bacterial cells grow and reproduce
-Parent cell enlarges
-Chromosomes are duplicated
-Cell envelope pulls together in the center of the cell to form a septum
-Cell divides into two daughter cells

63
Q

Generation/ doubling time

A

-The time required for a complete fission cycle
-Each new fission cycle doubles the population
-As long as the environment remains favorable, the doubling effect can continue at a constant rate
-The length of the generation time is a measure of the growth rate of an organism

64
Q

The growth curve of bacteria

A

-Lag phase
-Exponential growth
-Stationary phase
-Death phase

65
Q

Lag phase in growth curve

A

-Flat period on the graph when the population appears to not be growing or is growing slower than the exponential rate

66
Q

Exponential phase (logarithmic or log)

A

-Period where the curve increases dramatically
-Phase will continue as long as cells have adequate nutrients and favorable enviroment

67
Q

Stationary growth period

A

-Population enters survival modes and slows or stops growing.

68
Q

Death phase in growth curve

A

-Decline in growth rate caused by depleted nutrients and oxygen.

69
Q

Turbidometry

A

-A tube of clear nutrient solution becomes cloudy or turbid as microbes grow in it
-The greater the turbidity, the larger the population size (Lower percentage of light)

-Cells in a sample are counted microscopically
-Utilizes a cytometer calibrated to accept a tiny sample spread over a premeasured grid

70
Q

Practical importance of growth curve

A

-Antimicrobial agents rapidly accelerate the death phase
-Microbes in the exponential phase are more vulnerable to these agents than those in the stationary phase
-Actively growing cells are more vulnerable to conditions that disrupt cell metabolism and binary fission
-Growth patterns can correspond with the stages of infection:
-Bacterial shedding during the early and middle stages of infection is more likely to spread it to others

71
Q

Coulter counter

A

-Electronically scans a culture as it passes through a tiny pipette
-Each cell is detected and registered on an electronic sensor

72
Q

Flow cytometer

A

-Similar to a Coulter counter
-Can measure cell size and differentiate between live and dead cells

73
Q

Polymerase chain reaction (PCR)

A

-Quantifies bacteria and other microorganisms in environmental and tissue samples without isolating and culturing them

74
Q

Tests that measure ATP

A

-Used in food and pharmaceutical industries
-May be used for rapid quantification of microbes in other environmental samples