Nutrition
process by which chemical substances (nutrients) are acquired from the environment and used in cellular activities
Essential nutrients
must be provided to an organism
Macronutrients
required in large quantities; play principal roles in cell structure and metabolism
Proteins, carbohydrates
Micronutrients
or trace elements, required in small amounts; involved in enzyme function and maintenance of protein structure
Manganese, zinc, nickel
Organic nutrients
contain carbon and hydrogen atoms and are usually the products of living things
Methane (CH4), carbohydrates, lipids, proteins, and nucleic acids
Inorganic nutrients
atom or molecule that contains a combination of atoms other than carbon and hydrogen
Metals and their salts (magnesium sulfate, ferric nitrate, sodium phosphate), gases (oxygen, carbon dioxide) and water
96% of cell is composed of 6 elements
Carbon, Hydrogen, Oxygen, Phosphorous, Sulfur, Nitrogen
O: 21% N: 78% Other: 1%
What is the composition of the atmosphere?
300 parts per million
What is the concentration of CO2 in the atmosphere?
Chemoheterotroph
If an organism is degrading large organic molecules to get both carbon and energy, it would be best described as a?
Trance element
Microorganisms require small quantities of this nutrient for enzyme function and maintenance of protein structure?
Growth Factor
Organic nutrients that cannot be synthesized by the organism and must be provided is called?
Heterotroph
must obtain carbon in an organic form made by other living organisms such as proteins, carbohydrates, lipids, and nucleic acids
Autotroph
an organism that uses CO2, an inorganic gas as its carbon source
Not nutritionally dependent on other living things
Chemotroph
gain energy from chemical compounds
Phototroph
gain energy through photosynthesis
Chemoautotrophs
(lithoautotrophs) survive totally on inorganic substances
Heterotrophs
Majority are chemoheterotrophs
Aerobic respiration
Saprobes
free-living microorganisms that feed on organic detritus from dead organisms
Opportunistic pathogen
Facultative parasite
Parasites
derive nutrients from host
Pathogens
Some are obligate parasites
Passive transport
does not require energy; substances exist in a gradient and move from areas of higher concentration toward areas of lower concentration
Examples of Passive transport
Diffusion
Osmosis
Facilitated diffusion
Active transport
requires energy and carrier proteins; gradient independent
Group translocation
transported molecule chemically altered
Bulk transport
endocytosis, exocytosis, pinocytosis
Endocytosis
bringing substances into the cell through a vesicle or phagosome
Phagocytosis
ingests substances or cells
Pinocytosis
ingests liquids
Diffusion
The movement of molecules from an area of high concentration to lower concentration is:
Osmosis
Diffusion of water through a semipermeable membrane is called?
Active Transport
Movement of substances from lower to higher concentration across a semipermeable membrane that must have a specific protein carrier and use energy is called:
Facilitated diffusion
Movement of a substance from higher to lower concentration across a semipermeable membrane that must have a specific protien carrier but no energy is needed is called:
Niche
totality of adaptations organisms make to their habitat
Environmental factors affect the function of metabolic enzymes
Temperature, Oxygen requirements, pH, Osmotic pressure, Barometric pressure
Minimum temperature
lowest temperature that permits a microbe's growth and metabolism
Maximum temperature
highest temperature that permits a microbe's growth and metabolism
Optimum temperature
promotes the fastest rate of growth and metabolism
psycophiles
optimum temperature below 15oC; capable of growth at 0oC
mesophiles
optimum temperature 20o-40oC; most human pathogens
thermophiles
optimum temperature greater than 45oC
Aerobe
utilizes oxygen and can detoxify it
Obligated aerobe
cannot grow without oxygen
Faculative Anaerobe
utilizes oxygen but can also grow in its absence
Microaerophilic
requires only a small amount of oxygen
Anaerobe
does not utilize oxygen
Obligated Anaerobe
lacks the enzymes to detoxify oxygen so cannot survive in an oxygen environment
Aerotolerant Anaerobes
do not utilize oxygen but can survive and grow in its presence
capnophile
grows best at higher CO2 tensions than normally present in the atmosphere
acidophiles
grow at extreme acid pH
alkalinophiles
grow at extreme alkaline pH
Majority of microorganisms grow at a pH between
6 and 8 (neutrophiles)
Halophiles
require a high concentration of salt
Osmotolerant
do not require high concentration of solute but can tolerate it when it occurs
Barophiles
can survive under extreme pressure and will rupture if exposed to normal atmospheric pressure
Mutualism
obligatory, dependent; both members benefit
Commensalism
commensal member benefits, other member neither harmed nor benefited
Parasitism
parasite is dependent and benefits; host is harmed
Synergism
members cooperate to produce a result that none of them could do alone
Antagonism
actions of one organism affect the success or survival of others in the same community (competition)
Antibiosis
Biofilms
result when organisms attach to a substrate by some form of extracellular matrix that binds them together in complex organized layers
Quorum sensing
Communicate and cooperate in the formation and function of biofilms
Binary Fission (transverse)
Division of bacterial cells occurs mainly through
Generation, or doubling time
Time required for a complete fission cycle
Exponential growth
Each new fission cycle increases the population by a factor of 2
Rate of Population Growth
N� = (Ni)2n
Growth curve
In laboratory studies, populations typically display a predictable pattern over time
Lag phase
flat" period of adjustment, enlargement; little growth
Stages in the normal growth curve
Lag phase
Exponential growth phase
Stationary phase
Death phase
Exponential growth phase
a period of maximum growth will continue as long as cells have adequate nutrients and a favorable environment
Stationary phase
rate of cell growth equals rate of cell death caused by depleted nutrients and O2, excretion of organic acids and pollutants
Death phase
as limiting factors intensify, cells die exponentially
Methods of Analyzing Population Growth
Turbidometry, Degree of cloudiness, turbidity, reflects the relative population size
Turbidometry
Most simple way to analyze Population Growth
Enumeration of bacteria
Viable colony count
Direct cell count
count all cells present; automated or manual
Facilitated diffusion
The movement of substances from higher to lower concentration across a semi-permeable membrane that must have a specific protein carrier but NO energy expenditure is:
Growth Factor
An organic nutrient that cannot be sythesized by the organism and must be provided is?
Salt Lakes
A Halophile would grow best in
Active Transport
The movement of substances from lower to higher concentration across a semi-permeable membrane that must have a specific protein carrier and use energy?
Saprobes do not need a carbon source for growth and metabolism?
False
If a microbe is not capable of dealing with toxic oxygen, it is forced to live in oxygen free habitats?
True
Autotroph
An organism that used CO2 for its carbon needs would be called
Both parties benefit. EX: Lichen on bark
What is mutualism? Give an example of mutualism association in microorganisms and the partner of each in the association?
If a microbe is not capable of dealing with toxic oxygen, it is forced to live in oxygen free habitats?
True