Unit 2 Concept 2 - Cell Transport

need of an organism to stay stable by regulating internal conditions

it isn’t always the same, but it stays within the range

change in environment

change in the organism

evolved to help maintain homeostasis in organisms as they respond to stimuli

output of a system that intensifies the response

causes a counter response to return to a set point

homeostasis is maintained through regulation at the organ level-cellular level

selectively permeable membrane

passive and active

requires no extra energy

requires extra energy

(passive) spreading out of molecules across a membrane until equilibrium is reached, move down a concentration gradient

(passive) transports proteins and helps to facilitate the diffusion of molecules that normally couldn’t pass through the cell membrane

(passive) simple diffusion of water across cell membrane, move down a concentration gradient

water is lower than the cells cytoplasm, SHRIVELS

water is high than the cells cytoplasm, SWELLS

identical water to the cell’s cytoplasm, cell stays the SAME

(active) cell uses energy to pump molecules across the membrane, against the concentration gradient

(active) uses vesicles to move large particles into the cell

(active) uses vesicles to export materials out of the cell

cell eating

cell drinking