unit 1 - transport across cells Flashcards
what does cell membrane do?
controls movement of molecules into and out of cell
what do phospholipids do?
make up the cell membrane with proteins
what does the selectively permeable membrane do?
allows some molecules through but not others
what is passive transport?
movement of molecules that does not require energy
what is concentration gradient?
when there is a difference in concentration on each side of a cell membrane
what is diffusion?
the movement of molecules from higher concentration to lower concentration, down a concentration gradient
what is osmosis?
the movement of water from
higher water concentration to lower water concentration through a selectively permeable membrane
what does turgid mean?
a plant cell that has filled up with water
what does plasmolysed mean?
a plant cell that has shrunk as water moved out of it
what is active transport?
the movement of molecules and ions against the concentration gradient that requires energy
what are cell membranes made of?
consists of phospholipids and proteins
is the cell membrane selectively permeable?
yes
