chapter 5 section 1 Flashcards
Movement across the cell membrane without any input of energy by the cell; Higher concentration to lower concentration.
Passive transport
movement of molecule from an area of higher concentration to an area of lower concentration
diffusion
difference in the concentration of molecules across a space
concentration gradient
when the concentration of the molecules of a substance is the same throughout a space
equilibrium
the ability of a molecule to diffuse across a cell membrane depends on…..?
the size and type of the molecule and on the chemical nature of the membrane.
molecules that are very small but not soluble in lipids, diffuse across the cell membrane by moving through…..?
pores of the membrane.
the process by which water molecules diffuse across a cell membrane from a n area of higher concentration to an area of lower concentration is…
osmosis
the concentration of solute molecules outside the cell is lower than the concentration in the cytosol, the solution outside is _______ to the cytosol; water diffuses into the cell
hypotonic
the concentration of solute molecules outside the cell is higher than the concentration in the cytosol, the solution outside is ______ to the cytosol; water diffuses out of the cell
hypertonic
the concentration of solutes outside and inside the cell are equal
isotonic
organelles that remove water; collect excess water and pump out of the cell; requires energy
contractile vacuole
pressure that water molecules exert against the cell wall is ____
turgor pressure
In a hypertonic environment; water leaves the cell through osmosis. Cells shrink away from the cell walls, and turgor pressure is lost
plasmolysis
bursting of cells
cytolosis
process used for molecules that cannot diffuse rapidly through cell membranes,.
facilitated diffusion
_______ assist in the movement of molecules across a cell membrane ; higher concentration to lower concentration
carrier proteins
channels that assist certain ions in diffusing across the cell membrane.
ion channels
substances that can pass through cell membranes by diffusion include _____?
oxygen
the contractile vacuole of a paramecium should be active when the paramecium is in
a hypotonic environment.
when a human red blood cell is placed in a hypotonic environment, it will
undergo cytolosis
facilitated diffusion is often used to transport
molecules that are not soluble in lipids.
Na + ions enter cells by
diffusing through Na+ ion channels.
what type of stimuli can cause the gates on ion channels to open or close
stretching of the cell membrane
electrical signals
chemicals in the cytosol or external environment
