Chapter 7 Flashcards
(117 cards)
1
Q
Where are nutrients from and what are they used for?
A
From the enviorment and Cellular activites
2
Q
What kind of substance must be provided for microbial nutrition?
A
Essential nutrients
3
Q
What are organic nutrients?
A
Nutrients that contain carbon and hydrogen atoms, and they are usually the product of living things
4
Q
What are inorganic nutrients?
A
Atoms/ molecules that have other elements than carbon or hydrogen
5
Q
What is the difference between micro-and Marco-nutrients?
A
Macronutrients are required in very large amounts but micronutrients are much smaller and have a different enzyme and protein structure.
6
Q
What is a heterotroph?
A
An organism that must obtain its carbon in organic form
7
Q
Are heterotrophs dependent on other life forms?
A
Yes
8
Q
What must happen to allow heterotrophs to have absorption?
A
Larger molecules must be digested by the cell
9
Q
what are examples of the LMW compounds that heterotrophs use for absorption?
A
Amino acids, simple sugars, or organic acids (vinegar)
10
Q
How do autotrophs feed?
A
They are self feeders
11
Q
What is an autotroph?
A
An organism that uses inorganic CO2 as its carbon source, and it makes its own polymers protiens
12
Q
Are Autotrophs nutritent dependent on other living things?
A
No
13
Q
What is the most common component of inorganic salts?
A
Oxygen
14
Q
What plays a big role in the structural and enzymatic functions of the cell?
A
Oxygen
15
Q
What is a major component of carbs, lipids, nucleic acids and protiens?
A
Oxygen
16
Q
What are some of the roles of hydrogen in the cell?
A
Maintains pH, forming hydrogen bonds between molecules, and serving as the source of free energy in oxidation
17
Q
What is the main inorganic source?
A
Phosphorus or phosphate
18
Q
Where is phosphorus found naturally?
A
In rocks and oceaninc mineral deposits
19
Q
What is the key component of nucleic acids?
A
Phosphorus
20
Q
Where can sulfur be found?
A
Sulfur can be found widely distributed throughout the environment in rocks and sediments
21
Q
What is an essential component of vitamin b and amino acids methionine and cysteine?
A
Sulfur
22
Q
What is a growth factors of essential organic nutrients?
A
Must be provided by the enviorment, an organic compound such as an amino acid, nitrogenous base, or vitamin that cannot be synthesized by an organism
23
Q
How do photoautotrophs feed?
A
Capture energy from light rays and transform it into chemical energy that can be used for cell metabolism
24
Q
What do photoautotrophs produce?
A
They produce organic molecule that can be used by themselves and heterotrophs
25
What do Phototrophs do?
microbes that synthesize: photoauto and photoheterotrophs
26
What do Chemotrophs?
microbes that gain energy from chemical compounds: photoauto and photoheterotrophs
27
What do Chemoorganic autotrophs do?
use organic compounds for energy and inorganic compounds as a carbon source
28
Characteristics of Chemolithoautotrophs
require neither sunlight nor organic nutrients and rely totally on inorganic materials
29
What are methanogens?
chemoorganic autotrophs that produce methane from hydrogen gas and O2
30
How are methanogens formed and where?
Formed in anaerobic, hydrogen-containing microenvironments of soil, swamps, mud, or intestines of some animals
31
What can methan be used as?
Methane can be used as fuel and is a greenhouse gas
32
What makes up the majority of heterotrophic microorganisms?
Chemoheterotrophs
33
What is processed by Chemoheterotrophs
Organic molecules processed through respiration or fermentation release energy in the form of atp
34
How are aerobic respiration and photsynthesis related?
Aerobic respiration is photsyntheis backwards
35
What elements are in aerobic respiration
Glucose and oxygen are reactants, and carbon dioxide is given off
36
What is Aerobic respiration
main energy-yielding pathway in animals, Protozoa, fungi, and aerobic bacteria
37
What is dependent on aerobic respiration
Earths balance of energy and gasses
38
What are Saprotrophic or saprobic microorganisms
made up of and why is it important
Decomposed of plant litter, animal matter, and dead microbes, important in recycling nutrients held in organic materials
39
What do Saprotrophic or saprobic microorganisms do
Release enzymes (expenzymes) into the environment to digest food into smaller particles that can be transported inside of the cell
40
Characteristics of Saprotrophic or saprobic microorganisms
Most saprobes have a rigid cell wall and cannot engulf large particles of food
41
Where do parasitic microorganisms live
Live or in the body of a host
42
Can parasitic Mircoorganisms cause harm?
Yes
43
Why are parasitic organisms considered pathogens
Because they can damage tissues and cause death
44
What are obligate parasites?
Parasites that are unable to grow outside of a living host
45
What are Obligate intracellular parasites?
spend all or part of living their life cycle inside a host cell
46
What is done during nutrient absorption?
Necessary nutrients must be taken into the cell and waste materials must be transported out of the cell
47
Where does transportation occur during nutrient absorption?
Across the cell membrane
48
____________ _____________ are made up of decomposed plant litter, animal matter, and dead microbes
Saprotrophic or saprobic microorganisms
49
what is important in recycling nutrients held in organic materials
Saprotrophic or saprobic microorganisms
50
What has rigid cell walls and cannot engulf large particles of food?
Bacteria and fungi
51
What realeases renzymes into the enviorment to digest food into smaller particles that can be transported into the cell?
Saprotrophic or saprobic microorganisms
52
what lives on or in the body and causes some degree of harm to the host?
Parasite
53
Why are paratises considered pathogens
Because they can damage tissuses and cause death
54
Obligate parasites?
Unable to grow outside of a living cell
55
Obligate intracellular parasites?
Spend all or part of their life living inside a host cell
56
How do microbes feed?
Nutrient absorption
57
How does nutrient absorption work
Necessary nutrients must be taken into the cell and waste must be transported out of the cell
58
Where does transport happen during nutrient absorption
Across the cell membrane
59
What is diffusion?
The movement of molecules in a gradient from an area of higher concentration or density to a lower
60
What can diffuse freely through the membrane
O2, N2,CO2 and Steriods
61
What is osmosis
the move to of water across a selectively permeable membrane, water moves from a higher water content to a low water content
62
What are isotonic conditions?
When the solute concentration in the enviorment s equal to cell space .9% NaCl
63
Solute concentration of the enviomrent is lower than that of the cell
Hypotonic conditions
64
What is the most hypotonic enviomrent
Pure water
65
Enviomrent outside the cell has alight concentration of solutes than inside
Hypertonic conditions
66
What limits the growth of microbes
Hypertonic conditions
67
what is active transport
transport against concentration gradient, needs energy
68
what are the types of active transport
Endocytosis, Phagocytosis, Pinocytosis, Exocytosis
69
what is Endocytosis
transports large particles and or liquids inside cell (import): microvilli structures of intestinal epithelial cells absorb solid droplets
70
what is Phagocytosis
(solid import) endocytosis by amoebas and certain white blood cells (white blood cells, aka macrophages): ingest whole bacteria or particles or viruses
71
what is Pinocytosis
(liquid Import): entry of oils or molecules in solution into the cell
Exocytosis: transport of particles/ liquid outside of the cell (export)
72
what environmental factors influence microbes
Heat, cold, gasses, acid, radiation, osmotic pressure, hydrostatic pressure other microbes
73
Minimum temperatures (lowest extreme)
the lowest temp that permits a microbes continued growth and metabolism
Below this temp, activity is limited
74
Maximum temperature (highest extreme):
highest temperature at which growth and metabolism can proceed
Enzymes and nucleic acids will become denatured and the cell will die
75
Optimum temperature (in the middle)
intermediate temperature range between minimum and maximum
Promoted fastest rate of growth and metabolism
76
what are Psychrophiles
organisms have an optimum temperature below 15c
Capable of growth at 0c, cannot grow above 20c
77
how do Psychrotolerants grow
grow slowly in the cold, optimum temp 15c-30c
78
what temperatures work for Mesophiles:
individual species grow 10c-50c optimum: 20c-40c
Most human pathogens: 30c to 40c ( @human body temp, 98f)
79
what temps and environments do Thermophiles live in
grow optimally at temps above 45c (higher than 110f)
Live in soil/water associated w/ volcanic activity, compost piles, sun
Range of growth: 45c to 80c, extremophiles grow between 80c and 124c (100c=boiling point of water)
80
what are the three categories that microbes can fall under
1) those that use oxygen and can detoxify it
2) Those that can neither use oxygen nor detoxify it
3) Those that do not use oxygen but can detoxify it
81
what are the characteristics of Singlet oxygen
- very reactive produced both living and non living processes
- Produced by phagocytes (macrophages to kill pathogens
- Buildup of singlet oxygen and the oxidation products molecules can damage or destroy a cell (breaks down polymers
82
what are Obligate aerobes
an organism that connot grow without oxygen (human and certain bacteria
83
Characteristics of facultative anaerobe
runs aerobic respiration (make atp) when O2 is present
Does not require o2 for its metabolism (manufactures atp either using anaerobic respiration- with NO3,SO4, or ferments)
84
True or false: aerotolerant anaerobes use oxygen
False
85
Characteristics of aerotolerant anaerobes
do not use o2 at all (runs anaerobic respiration or ferments at all times)
Can survive and grow to a limited extent in its presence of O2, bc they can break down peroxides and superoxides
86
Anaerobe(anaerobic microorganism)
lacks the enzymes for using oxygen in respiration
Strict or obligate anaerobes and will die if O2 is present
Live in highly reduced habitats such as deep muds, lakes, oceans, and soil
87
Culturing types for anaerobes
glove bag: less fancy,
controlled atmospheric chamber more fancy
Jar- cannot be used for obligate anaerobes
88
The degree of acidity or alkalinity for a solution
PH
89
What is the pH of pure water
7 or neutral
90
How does the pH scale work
0 more acidic, 14 most alkaline
91
Characteristics of Obligate acidophilies
Require an acidic environment for growth
Molds and yeasts tolerate acid and are common spoilage agents of pickled foods
92
Characteristics of Alkaliphiles (or alkalinophiles)
Live in hot pools and solid that contain high levels of basic materials
Bacteria that decompose urine create alkaline conditions
93
Where do osmophiles live
In habitats with high solute concentration
94
Habitats of Obligate halophiles
Require high concentrations of salt for growth (9 to 25% of NaCl)
Have significant modifications of their cell walls & membranes and will die in hypotonic habitats; live in super salty water bodies (salt lakes, Dead Sea)
95
Habitats of Facultative halophiles
Resistant to salt, but don’t normally live in there (seasonal drying, salty ponds)
96
What are basophils
deep sea microbes: 1000 times atmospheric pressure
Rupture when exposed to normal atmospheric pressure
97
Antagonism (between microbes)
Sorta like competion, happens when memebers of a community compete.
One microbe secretes chemical substances into the surrounding environment that inhibit or destroy other microbes
98
What are antibiotics
A form of antagonism, penicillin
99
Symbiosis
a general term used to donate a situation in which two organisms live together in a close partnership
100
What is mutualism
(++) both benefit, happens when the organisms live in a mutually beneficial relationship (ex: e.coli: produces vitamin K, we give it food)
101
What is commensalism
Relationship benefits (plus) one member and does not harm the other
102
What is parasitism or predation
(+-) in this case the host provides habitat and nutrients, multiplication causes some form of multipulcation
103
What are biofilm
biofilms are mixed comminutes of different kinds of bacteria and other microbes plus their extracellular organic compounds (usually polysaccharide): forms a cemented bacterial layer
104
What are the steps of population growth
1) a young cell
2) Chromosome is replicated and new and old chromosomes move to different sides of cell
3)Protein band forms in center of cell
4)Septum formation
5)When septum is complete cells are considered divided. Some species will separate completely as shown here, while others remain attached forming chains or doublets
105
What is binary fission
Asexual reproduction predation of the body into two new bodies
106
Steps of binary fission
-parent cell enlarges chromosomes (DNA) and other organelles are duplicated
-Cell envelope pulls together in the center of the cell to form a wall to wall protein band
-Septum formation (newly forming divider) begins
-Cell divides into two daughter cells
107
Population/ exponential growth
generation time or doubling time
108
How does the population grow each fission cycle
The population doubles each cycle
109
Lag phase
flat period on the graph: no apparent growth due to adjustment
110
Exponential growth or log phase
-period during which the growth rate increases dramatically numbers grow exponentially (geometric progression 2,4,8,16,32
-Will continue as long as adequate nutrients and environment
111
Stationary growth phase
survival mode: stop growing or grow slowly due to nutrient limitations (because they ate everything)
112
Death phase
-limiting factors intensify, cells dis at an exponential rate
-Curve dips downward
-Microbes in the exponential phase are more vulnerable to antibacterial agents (i.e, penicillin will kill growing cells faster
-Actively growing cells are more vulnerable to factors disrupting metabolism and binary fission
113
What is a batch reader (bacteria cultivation)
Media is loaded, bacteria (or yeasts) are inoculated, the reactor is sealed and let grow for a while. Cells display typical growth curve (as nutrients are depleted, they begin to die) example: beer making
114
Continuous growth system aka (chemostat)
-Continuous culture system (continuous bioreactor) that allows a steady stream of new nutrients and removes the spent media (waste)
-Maintains the culture in a biochemically active state and prevents it from entering the death phase
-Industrial application; industrial antibiotic production: some antibiotics are produced by fungi (bacteria) only in stationary phase: chemostat allows tweaking to make culture stay in it
115
Direct microscopic count (eye)
-direct total cell count: (bacterial and blood cells)
-Cells in a sample are counted microscopically by eye
-Uses a counting chamber (drop spread over a pre measured grid)
-Pros: precise
-Cons: laborious (highly trained personnel, really slow)
116
Flow cytometer & coulter counter
-coulter counter and flow cytometer (automated)
-Electronically scans cells as it passes through a hole
-Cells are detected (light scattering) and made into signals
-Flow cytometer: combines this with live/dead staining
-Allows to count live and dead cells separately
-Pros; high efficiency
-Cons; can underestimate clustered cells
117
New methods of analyzing population growth
quantitative polymerase chain reaction (qPCR) 4-6hr, Test that measure ATP (10-30 mins): ATP is intact in only live cells
