chapter 9 vocab

autotroph

can use inorganic sources of carbon to make it into food

heterotroph

obtain carbon from other sources (organisms)

essential nutrient

carbon, hydrogen, oxygen, nitrogen, phosphourus, sulfur

macronutrient

required in large amounts

cell structure, metabolism

ex.) C, H, O

saprobe

a microbe that decomposes organic remains from dead organisms

osmosis

diffusion of water through a selective membrane

diffusion

the dispersal of molecules down a concentration gradient by random moion to achieve a uniform distribution

isotonic

2 solutions havng the same osmotic pressure and having no net movement of solvent

hypertonic

having a greater osmotic pressure than a reference solution

hypotonic

having a lower osmotic pressure than a reference solution

active transport

movement of molecules from low to high AGAINST the concentration gradient

USES ENERGY

facilitated diffusion

movement of molecules from high to low with the use of PROTEINS

DOES NOT USE ENERGY

endocytoisis

type of active transport

movement of molecules into the cell via invagination

exocytosis

also active transport

pinocytosis

engulfing of liquids (oils, mols.)

phagocytosis

engulfing of whole cells (amoebas, wbcs)

psychrophile

found in cold water, soil, not in humans

psychrotolerant

grow slowly at low temperature, can cause food to spoil

mesophile

most medically significant bacteria; human pathogens

can also be psychotolerant and thermoduric

thermophile

hot springs

extreme thermophile

archaea, deep-sea vents, require autoclaving (heating in autoclave) for isolation

optimum temperature

intermediate range that promotes fastest growth rate and metabolism

thermoduric microbe

survives small expoures to high heat, contaminate pasteurized foods (giardia, bacillus, clostridium)

obligate aerobe

must have oxygen to live, have enzymes to process oxygen (fungi, protists, bacteria)

obligate anaerobe

can not grow if oxygen is present, do not have enzymes to process oxygen

microaerophile

do not grow at normal oxygen concentrations, require a little amount of oxygen

facultaive anaerobe

can grow in aerobic conditions but can switch to anaerobic metabolism whn there is no oxygen, have enzymes to process oxygen

aerotolerant anaerobes

do not use oxygen but can survive in the presence of oxygen (have alternatemethods to break peroxides and superoxide)

halophiles

can grow best at high salt concentrations

barophiles

loves pressure (keeps enzymes in correct shape), die at standard atmosphere pressure

acidophiles

loves acidic pH (1.0-5.5)

alkhaliphiles

loves basic pH (8.5-11.5)

neutrophiles

loves neutral pH (most bacteria)

pH 5.0-8.0

used in preservation, pickling (inhibits growth)

lag phase

cells are adjusting to media, synthesizing new material needed for replication

exponential growth phase

(log phase)

cells produce primary metabolites (compounds needed for growth, waste)

stationary phase

cells are dying, release molecules that other cells can use for growth

death phase

end of cell growth due to lack of nutrition, depletion of environment, and accumulation of wastes

chemostat

device that supplies fresh medium to the growth chamber, withdraws old medium to maintain logarithmc growth

turbidity

cloudy appearance of nutrient solution in a test tube due to growth of microbe population