Lecture 3 Vocab

Front 1

turgid

Back 1

firm - a plant cell is turgid when it is in a hypotonic environment

Front 2

flaccid

Back 2

limp - a plant cell is flaccid when it is in an isotonic environment

Front 3

plasmolysis

Back 3

what happens when a plant cell is in hypertonic environment, the cytoplasm shrinks, and the cell membrane pulls away from the cell wall

Front 4

diffusion

Back 4

net movement of molecules down a concentration gradient, due to the random motion of individual molecules

Front 5

osmosis

Back 5

diffusion of water across a selectively permeable membrane

Front 6

passive transport

Back 6

transport of a molecule down its concentration gradient, which does not require the cell to expend energy

Front 7

active transport

Back 7

transport of a molecule against its concentration gradient, which requires the cell to expend energy

Front 8

channel proteins

Back 8

provide a path for a certain type of molecule to travel across the membrane via facilitated diffusion

Front 9

carrier proteins

Back 9

move a molecule across the membrane by changing their conformation (shape). can be used in active and passive transport.

Front 10

cotransport

Back 10

a kind of active transport in which the energy released from one molecule moving down its concentration gradient is used to power the transport of a different molecule against its concentration gradient

Front 11

electrogenic pump

Back 11

a transport protein that generates voltage across a membrane

Front 12

proton pump

Back 12

a carrier protein that actively transports H+ ions out of the cell

Front 13

vesicle

Back 13

a sac made of membrane in the cytoplasm

Front 14

exocytosis

Back 14

fusion of vesicles with the plasma membrane resulting in release of molecules to the extracellular fluid

Front 15

endocytosis

Back 15

fusion of vesicles with the plasma membrane resulting in uptake of molecules into the cell

Front 16

phagocytosis

Back 16

"cell-eating" a kind of endocytosis in which the cell engulfs a large particle and encloses it in a vesicle

Front 17

pinocytosis

Back 17

"cell-drinking" a kind of endocytosis in which the cell takes up a drop of extracellular fluid, along with any and all solutes in the fluid, into a vesicle

Front 18

receptor-mediated endocytosis

Back 18

a kind of endocytosis in which the cell uses receptor molecules on the outside of the membrane to bind a specific molecule it needs, and then takes up the molecules in a vesicle

Front 19

aquaporin

Back 19

a channel protein that allows facilitated diffusion (osmosis) of water through the cell membrane