Micro Chapter 7

Front 1

Nutrition

Back 1

Process by which chemical substances called nutrients are acquired from environment and used in cellular activities

Front 2

Essential nutrient

Back 2

Element/compound that must be provided to an organism macro

Front 3

Macronutrient

Back 3

Required in large quantities

Front 4

Micronutrient

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Required in smaller amounts (iron, zinc, etc)

Front 5

Organic nutrients

Back 5

Molecules that contain carbon and hydrogen-- product of living things

Front 6

Inorganic nutrients

Back 6

Composed of elements other than carbon or hydrogen-- mineral deposits in the soil, water, or atmosphere

Front 7

Heterotroph

Back 7

Organism that obtains carbon in organic form-- dependent on other life forms

Front 8

Autotroph

Back 8

Used inorganic carbon dioxide as its carbon source-- converts carbon dioxide into organic compounds-- not dependent on other life forms

Front 9

Growth factor

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Organic compound that cannot be synthesized by an organism and must be provided as a nutrient (cells require 20 amino acids but can't make all so some are obtained through food)

Front 10

What are the main determinants of a microbe's nutritional type?

Back 10

It's sources of carbon and energy

Front 11

Phototrophs

Back 11

Photosynthesize to get energy

Front 12

Chemotrophs

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Gain energy from chemical compounds

Front 13

Photoautotrophs

Back 13

Photosynthetic; converts light energy into chemical energy

Front 14

Oxygenic photosynthesis

Back 14

Oxygen-producing (plants, algae, cyanobacteria)

Front 15

Anoxygenic photosynthesis

Back 15

No oxygen produced

Front 16

Chemoautotrophs

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Bacteria/archaea that survive on inorganic substances such as minerals and gases

Front 17

What drives the synthetic process of the cell?

Back 17

Chemoautotrophs remove electrons from inorganic substrates (hydrogen gas, hydrogen sulfide, sulfur, iron) and combine them with other inorganic substances (carbon dioxide, oxygen, hydrogen) which releases simple organic molecules and energy

Front 18

Methanogens

Back 18

Archaea found in extreme habitats-- metabolism adapted by producing methane gas

Front 19

Chemoorganotrophs

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Derive both carbon and energy from organic compounds (majority of heterotrophs)

Front 20

Chemoheterotrophs

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Require organic carbon source

Front 21

Saprobes

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Free living microbes that feed on organic matter released by dead organisms

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Symbionts

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Derive organic nutrients from bodies of living organisms

Front 23

Saprobe characteristics

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Decomposers of plant litter, animal matter and dead microbes-- can't engulf food, releases enzymes to extracellular environment to digest food particles into smaller molecules that can be transported into cell (bacteria, fungi)

Front 24

Facultative parasite

Back 24

Doesn't rely on host for completion of life cycle, but CAN be parasitic

Front 25

Parasites

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Invades the body of a host and uses it as a habitat and source of nutrients and harms the host

Front 26

Pathogens

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Parasitic microbes that grow inside sterile tissues and cause damage/death

Front 27

Ectoparasites

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Live on the body

Front 28

Endoparasites

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Live in organs and tissues

Front 29

Obligate parasites

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So dependent on the host that they can't survive/grow on their own

Front 30

Diffusion

Back 30

Net movement of molecules down concentration gradient by random thermal motion-- molecules become dispersed from area of high concentration to area of low concentration which makes them evenly dispersed in solution

Front 31

Increase in what makes molecules move faster?

Back 31

Kinetic energy

Front 32

Passive transport

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Does not require energy-- diffuses across the membrane

Front 33

Osmosis

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Diffusion of water through selectively permeable membrane

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Isotonic conditions

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Environment is equal in solute concentration to cell's internal environment-- diffusion of water proceeds at same rate in both directions so there is no net change in cell volume

Front 35

Hypotonic conditions

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Solute concentration of external environment is low than that of the cell's internal environment-- cells without walls can swell and burst when exposed to this condition

Front 36

Hypertonic environment

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Exposed to solution with higher solute concentration than it's cytoplasm-- forces water to diffuse outside of cell

Front 37

Plasmolysis

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Shrinkage of protoplast in cells without a cell wall

Front 38

Turbid

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Swollen/congested cytoplasmic membrane

Front 39

Amoeba

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Has no cell wall so it must expend extra energy to deal with influx of water-- accomplished with a water vacuole that pushes excess water out of cell

Front 40

Facilitated diffusion

Back 40

Transport mechanism that uses carrier protein in membrane that will bind to a specific substance-- changes conformation of carrier protein in a way that facilitates movement of substance across membrane

Front 41

When is facilitated diffusion used?

Back 41

When the substance is less permeable and diffusion is unable to transport it

Front 42

Specificy

Back 42

Carrier proteins that bind and transport only a single type of molecule

Front 43

Aquaporins

Back 43

Water channels; facilitate transport of water molecules following existing osmotic gradient-- regulate volume and osmotic pressure

Front 44

What must a microbe do to ensure constant supply of nutrients?

Back 44

Capture nutrients in low concentrations and actively transport them into the cell

Front 45

Carrier-mediated active transport

Back 45

Functions with specific membrane proteins that bind ATP and molecules to be transported-- release of ATP drives molecule through protein carrier

Front 46

Group translocation

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Couples transport of a nutrient with its conversion to a substance that's immediately useful inside the cell

Front 47

Endocytosis

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Cell encloses substance in membrane, forming a vacuole and engulfing it

Front 48

Phagocytosis

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Amoebas and certain white blood cells ingest whole cells or large solid matter

Front 49

Pinocytosis

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How liquids enter the cell (oils: molecules in solution)

Front 50

Minimum temperature

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Lowest temp that permits a microbe's growth and metabolism

Front 51

Maximum temperature

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Highest temp that permits growth and metabolism-- any higher can cause denaturation and death

Front 52

Optimum temperature

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Between minimum and maximum temps that promotes fastest rate of growth and metabolism

Front 53

Psychrophile

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Microorganism with optimum temp below 15 degrees C but can grow at 0-- can't grow above 20 degrees C

Front 54

Mesophiles

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Organisms that grow at intermediate temps-- optimum growth temp is 20-40 degrees C-- inhabit animals, plants, soil and water (guardia, bacillus,clostridium)

Front 55

Thermophile

Back 55

Microbe that grows optimally at temps greater than 45 degrees C-- live in soil and water

Front 56

Hyperthermophiles

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Grow between 80-121 degrees C

Front 57

Atmospheric gases that most influence microbial growth

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Oxygen and carbon dioxide

Front 58

Singlet oxygen (1O2)

Back 58

Produced by phagocytes to kill invading bacteria-- buildup of singlet oxygen can damage and destroy cell

Front 59

Capnophiles

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Grow best at higher carbon dioxide tensions than are normally present in the atmosphere

Front 60

Neutrophiles

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Microorganisms living in soil, fresh water or bodies of plants/animals that live within the range of pH 5.5-8

Front 61

Acidophiles

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Include Eugenia mutabilis and Thermoplasma-- grows in acid pools between 0-1 pH

Front 62

Alkalinophiles

Back 62

Live in pools/soils that contain high levels of basic minerals

Front 63

Syntrophy/cross feeding

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Community feeding of organisms sharing a habitat-- products given off by one organism are usable to another

Front 64

Amensalism

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One microbe causes adverse effect in another-- involves competition and occurs where microbes share space/nutrients

Front 65

Antibiosis

Back 65

Release of natural chemicals/antibiotics to kill other microbes (fungi and bacteria use this)

Front 66

Biofilms

Back 66

Used as adaptive strategy-- favors persistence in habitats and offers greater access to life sustaining conditions

Front 67

Quorum sensing

Back 67

Swimming microbes (planktonic) attracted to surface and settle down-- stimulates cells to secrete slimy/adhesive matrix that binds them to substrate, and once attached cells release inducer molecules

Front 68

Inducer molecules

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Accumulate as cell population grows (can monitor size of their own population)-- stimulates expression of particular gene and synthesis of protein product

Front 69

Binary fission

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How bacteria cells replicate-- parent cell splits into 2 daughter cells

Front 70

Generation time

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Time required for complete fission cycle-- average time for bacteria is 30-60 minutes

Front 71

Chemostat

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Continuous culture system-- admits steady stream of new nutrients off used media and old bacterial cells to stabilize growth rate and prevent culture from entering death phase

Front 72

Cell content

Back 72

70% water

Proteins

96% CHNOPS

Front 73

Halophiles

Back 73

Require high concentration of salt

Front 74

Osmotolerant

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Do not require salt but can tolerate it

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Lag phase

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Flat period of adjustment, little growth

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Exponential phase

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Maximum growth

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Stationary phase

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Nutrients depleted and oxygen gone-- rate of cell growth equal to rate of cell death

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Death phase

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Cells die as factors intensify

Front 79

Aerobe

Back 79

Uses oxygen and can detoxify it

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Obligate aerobe

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Cannot grow without oxygen

Front 81

Facultative aerobe

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Utilizes oxygen, but can grow without it

Front 82

Microaerophilic

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Require small amount of oxygen

Front 83

Anaerobic

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Does not utilize oxygen

Front 84

Obligate anaerobe

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Lacks enzymes to detoxify oxygen so it can't survive in oxygen environment

Front 85

Aerotolerant anaerobes

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Does not utilize oxygen but can grow in its presence

Front 86

Symbiotic

Back 86

Organisms live in close nutritional relationships--required by one or both members

Front 87

Nonsymbiotic

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Relationships not required for survival

Front 88

Mutualism

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Both members benefit

Front 89

Commensalism

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Other member doesn't benefit but not harmed

Front 90

Parasitism

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Parasite dependent and benefits-- host harmed

Front 91

Synergism

Back 91

Members cooperate and share nutrients

Front 92

Antagonism

Back 92

Some members inhibited/destroyed by others