Create an account
needed in small amounts and is involved in the enzyme function and maintenance of protein structure
materials that cannot be made by an organism but necessary to sustain life and must be supplied by the diet.
hydrocarbons- methane ; macromolecules-carbohydrates, lipids, proteins, and nucleic acid
metals and their salts (potassium, calcium, sodium, magnesium, iron); gases (oxygen, carbon dixiode); water
enviromental sources of nutrients
Air 79% nitrogen 20% oxygen / Water- essential to metabolic processes/ Soil - minerals
organisms that must obtain carbon in an organic form- they feed on other organisms or the products of other organisms metabolism
passive, but requires a membrane protein--protein allows channel to allow passage--polar molecules like H2O & glucose
carrier mediated active transport requires energy and membrane proteins- faster transport rates- has pump to cross conc. gradient
affect the rate and amount of growth, survival depends on adaptions to changing envrioments
enviromental factors examples
temperature, oxygen, ph, electromagnetic radiation, barometric and osmotic pressures
oxidizning agent examples
singlet oxygen, superoxide ion, peroxide, and hydroxide radicals are toxic
can use gaseous oxygen in its metabolism and posseses the enzymes needed to process toxic oxygen products.
does not require oxygen for its metabolism and is capable of growing in the absence of it. ----has growth throughout the tube
lacks the metabolizing enzyme system for using gas in respiration----growth only in bottom of tube
does not grow in normal atmospheric oxygen but does need a little oxygen for metabolism---these organisms live in the soil, human body, and water,,,not directly exposed to oxygen---growth in tube just below the surface.
close nutritional relationships between organisms-essential and beneficial to at least one member
protozoa digests,cellulose for termites, bacteria breakdown cellulose for ruminates, E.coli produces vit k in large intestine
the time elapsed between formation of a new daughter cell and the time when it divides to form 2 new cells
four stages normal growth curve
lag phase, log or exponential phase, stationary phase, and death phase
exponential growth phase
period of maximum growth will continue to grow as long as cells have adequate nutrients and a favorable enviroment
rate of cell growth equals rate of cell death, caused by a depleted amount of nutrients and oxygen excretion of organic acids and pollutants
as limiting factors intensify cells die exponentially in their own wastes ...these cells are not supported by their enviroment
Please allow access to your computer’s microphone to use Voice Recording.
Having trouble? Click here for help.
We can’t access your microphone!
Click the icon above to update your browser permissions and try again
Reload the page to try again!Reload
Press Cmd-0 to reset your zoom
Press Ctrl-0 to reset your zoom
It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.
Please upgrade Flash or install Chrome
to use Voice Recording.
For more help, see our troubleshooting page.
Your microphone is muted
For help fixing this issue, see this FAQ.
Star this term
You can study starred terms together