chapt 7

a process by which chemical substance are acquired from the enviroment and used in cellular activities such as growth/metabolism

nutrients are processed and transformed into chemicals of the cell after absorption

any substance that must be provided to an organism

required in large quanities

trace elements present in smaller amounts

a combination of atoms other than c and H

contain C and H-present in all living things

chonps

• carbon 50%
• hydrogen
• oxygen 20%
• nitrogen
• phosphorus
• sulfur

must obtain carbon in organic form

nutritionally dependent on other living things

self feeder

not nutrionally dependent on other living things

microbes that photosynthesize energy from sunlight

microbes that gain energy from chemical compounds

• photo-sunlight for energy
• auto- co2 carbon source

• chemo-inorganic chemical for energy
• auto- co2 ar carbon source

derive both carbon and energy from organic compounds

• saprobes
• parasites

• free living microorganisms
• feed primarily on organic detritus from dead oragnisms
• decomposers of plant litter,animal matter, and dead microbes
• include fungi and bacteria

derive nutrients from the cells or tissues of a host and cause some degree of damage to the host

also called pathogens because they cause diease

live in the body

live in organs and tissues

live within cells

unable to grow outside of a living host

occurs across the cell membrance  in organisms with a cell wall, the wall is too permeable  to control molecules entrance or exit in the cell

osmosis, diffusion,facilitated  diffusion

no energy required

endocytosis

requires energy

diffusion of water through a selectivly permeable membrane from an area of more dilution to an area of less dilution

it allows passage of some molecules but not others

the enviroment  is equal in solute concentration  to the cells internal enviroment

most stable

the solute concentration of the external enviroment is lower then that of the cells internal enviroment

net direction od osmosis is from the hypotonic  solution into the cell

cells without cell walls swell and can burst -LYSIS

the enviroment has a hight solute concentration  then cytoplasm

will force water to diffuse out of a cell

has high osmotic pressure

will swivel

diffusion of molecules across the cell membranes  is largly  detrmined by the concentration gradient  and permeability of the substance

nutrrients are transported against the diffusion/concentraction  gradientb  or in the same direction as the natural gradient but ata rate faster than by diffusion alone

equires the presence of specific membrane proteins

requires expenditure of energy

cell eating

amoebas and certain white blood cells ; ingesting whole cells or large solid matter

cell drinking

transport of liquids such as oils or molecules in solution

the range of temperature  for the growth of a given microbial species, they assume the ambiant temperature of thier natural habitat

a microrganism that has a optimum temperature below 15 and is capable of growth below 0

grow slowly in cold but have an optimum temperature above 20

• a organism that grows in intermediate temp
•  optimum growth 20 to 40

a microbe that grows at temp greater then 45

can use gasous oxygen and posseses the enzyme needed to process toxic oxygen productas

can not grow witout oxygen

can utilize oxygen-prefers it

does not grow at normal atmospheric concentration of oxygen but requires a small amount of it in metabolism

lacks the metabolic  enzyme systems for sing oxygen in respiration

lack the enzyme  for processing toxic oxygen and con not tolerate  aniy free oxygen in the immediat enviroment and will die if exposed to it