Microbio Ch. 7

Vocab and concepts from chapter 7 - "Microbial Nutrition, Ecology, and Growth"

obligatory relationship, dependent; both members benefit =

mutualism

relationship in which the commensal benefits; the host is unharmed =

commensalism

relationship in which the parasite is dependent and benefits; host is harmed =

parasitism

relationship in which members cooperate and share nutrients =

syntrophy

relationship in which some members are inhibited or destroyed by others =

antagonism

bacteria communicate within a biofilm by sending each other chemical signals in a process known as _____

quorum sensing

what is the first stage of biofilm formation and quorum sensing?

reversible attachment

what is the second stage of biofilm formation and quorum sensing?

irreversible attachment (quorum sensing)

what is the third stage of biofilm formation and quorum sensing?

microcolony - first maturation stage

what is the fourth stage of biofilm formation and quorum sensing? (bacteria using quorum sensing to diversify and change their environment)

mature biofilm

what is the fifth stage of biofilm formation and quorum sensing? (biofilm becomes so large that it breaks open at the top, dispersing bacteria and spreading it by starting the process over again at step 1)

dispersal

the human body is a rich habitat for symbiotic bacteria, fungi, and some protozoa =

normal microbiota

an organism that must obtain carbon in an organic form made by other living organisms such as proteins, carbs, lipids, and nucleic acids =

heterotroph

an organism that uses inorganic molecules (i.e. CO2) as its carbon source, not nutritionally dependent on other living things =

autotroph

an organism that gains energy from chemical compounds =

chemotroph

an organism that gains energy from ORGANIC chemical compounds =

chemoorganotroph

an organism that gains energy from INORGANIC chemical compounds =

chemolithotroph

an organism that gains energy through photosynthesis =

phototroph

free-living microorganisms that that feed on organic detritus from dead organisms - oppurtunistic pathogen, facultative parasite =

saprobes

organisms that derive their nutrients from a host - pathogens, some are obligate =

parasite

organic compounds that cannot be synthesized by an organism because they lack the genetic and metabolic mechanisms to synthesize them (i.e. essential amino acids, vitamins, etc., haemophilus influenza) =

essential growth factors (essential nutrients)

transport that does not require energy; substances exist in a gradient and move from areas of higher concentration to areas of lower concentration =

passive transport

what are the 3 types of passive transport?

osmosis, diffusion, and facilitated diffusion (carrier)

transport that requires energy and a carrier protein regardless of gradient =

active transport

examples of active transport =

exocytosis, endocytosis, pinocytosis

a _____ solution has less water and more solutes

hypertonic

a _____ solution has more water and less solutes

hypotonic

an _____ solution has equal water and equal solutes

isotonic

if an isotonic cell is placed in an isotonic solution, what will occur?

nothing

if a hypertonic cell is placed in a hypotonic solution, what will occur?

water diffuses into the cell, solutes diffuse out, cell swells and may lyse

if a hypotonic cell is placed in a hypertonic solution, what will occur?

water diffuses out of the cell, solutes diffuse in, cell shrinks and may cause plasmolysis

bringing substances into the cell through a vesicle or phagosome, requires energy =

endocytosis

ingestion of substances or cells =

phagocytosis

ingestion of liquids =

pinocytosis

totality of adaptations an organism makes to their habitat

niche

the lowest temperature that permits a microbes growth and metabolism =

minimum temperature

highest temperature that permits a microbes growth and metabolism (ex. fever in a human) =

maximum temperature

promotes the fastest rate of growth and metabolism =

optimum temperature

an organism that has an optimum temperature below 15C (59F), capable of growth at 0C (32F) =

psychrophile

an organism with an optimum temperature of 20-40C (68-104F); most human pathogens =

mesophiles

an organism with an optimum temperature greater than 45C (113F) =

thermophile

as oxygen is utilized it is turned into the following toxic products =

singlet oxygen, superoxide ion, peroxide, and hydroxyl radicals

what are the enzymes that most organisms produce which neutralize the toxic products of oxygen use?

superoxide dismutase, catalase

an organism that utilizes oxygen and can detoxify it =

aerobe

an organism that cannot grow without oxygen =

obligate aerobe

an organism that utilizes oxygen but can also grow in its absence =

facultative anaerobe

an organism that only requires a small amount of oxygen =

microaerophilic

an organism that does not utilize oxygen =

anaerobe

an organism that lacks the enzymes to detoxify oxygen so cannot survive in an environment that contains oxygen =

obligate anaerobe

an organism that does not utilize oxygen but can survive and grow in its presence =

aerotolerant anaerobe

an organism that grows best at higher CO2 levels than normally present in the atmosphere =

capnophile

a microorganism that grows at a pH between 6 and 8 =

neutrophile

an organism that grows at extreme acid pH (low) =

acidophile

an organism that grows at extreme alkaline, or basic, pH (high) =

alkalinophile

an organism that requires a high concentration of salt =

halophile

an organism that does not require a high concentration of solute but can tolerate it when It occurs =

osmotolerant

an organism that can survive under extreme pressure and will rupture if exposed to normal atmospheric pressure =

barophilae

time required for a complete fission cycle =

generation or doubling time

each new fission cycle increases the population by a factor of 2 - the rate of growth is greater than the rate of death =

exponential growth phase

in lab studies, populations typically display a predictable pattern over time called a _____

growth curve

“flat” period of adjustment, enlargement, little growth =

lag phase

the rate of cell growth equals rate of cell death caused by depleted nutrients and O2, excretion of organic acids and pollutants =

stationary phase

as limiting factors intensify, cells die exponentially =

death phase

what are the phases in order of the population growth curve?

lag, exponential growth, stationary, death

chemical substances acquired from the environment that are used in cellular activities are known as _____

nutrition

what are the 3 types of symbiotic relationships?

mutualism, commensalism, parasitism

what are the 2 types of non-symbiotic relationships?

synergism (aka syntrophy), and antagonism

an acidic pH ranges from =

lower than 7, down to 0

division of bacterial cells is called =

binary fission

most microbes exist under which two conditions?

isotonic or hypertonic

an atom or molecule that contains a combination of atoms other than carbon and hydrogen =

inorganic nutrients

a neutral pH is =

7

an alkaline or basic pH ranges from =

greater than 7, up to 14

all microbes require _____ in their diet

carbon dioxide

what are the environmental factors that influence microbes?

temp, oxygen requirements, pH, osmotic pressure, barometric pressure

proteins and carbohydrates, required in large quantities and play a principal role in cell structure and metabolism =

macronutrients

what are the 3 cardinal temperatures?

minimum, optimum, maximum

where would you most likely find growth of a microbe that is an anaerobe?

deep soil layers with no exposure to air

according to the “me, myself, us” article, riboflavin bacteria produce _____ to assist with the digestion of breast milk

glycoside hydrolase

inhibitors of quorum sensing proteins may become future _____

antibiotics

a microorganism’s ability to cause disease is described as =

pathogenicity

the severity of the disease caused is described as =

virulence

proteins or other factors that increase the likelihood a disease will occur =

virulence factors