Active and Passive Transport Quiz

passive transport

movement of a substance across the cell membrane without energy

simple diffusion

movement of a substance from high to low concentration until equilibrium is reached

ex of simple diffusion

lysol sprayed in classroom; food coloring added to water

concentration

number of molecules in a given unit of volume

equalibrium

condition where the concentration of a substance is equal

concentration gradient

difference in the concentration of a substance across a space

diffusion occurs ______ the concentration gradient from ____ to ____

down; high; low

is diffusion faster or slower over short distances?

faster

why do small molecules that are non polar/uncharged diffuse easily across the cell membrane?

the interior of cell membrane or the phospholipid bilayer is nonpolar

osmosis

diffusion of water through a membrane

solute

substance dissolved in a solution

solvent

substance in which the solute is dissolvedso

solution

a substance dissolved in another substance

where does water move from

less solute which has more free water molecules to more solute with less free water molecules

hypertonic solution

when there is less solute in a cell and more free water and more solute outside the cell and less free water

what is a hypertonic solution

salty/sugary; high in solutes

what way does the water flow in a hypertonic solution

out of the cell

hypotonic solution

when there are more solute and less free water molecules in a cell and less solute and more free water molecules outside the cell

what is a hypotonic solution

not salty/sugary; low in solutes

result of a hypertonic solution

cell shrinkage (in plants called plasmolysis)

result of a hypotonic solution

cell swells (if bursts called cytolysis)

isotonic solution

equal solute and free water molecules amount; cell size remains unchanged

plant cells swell (hypotonic) as they fill with water and creates ________

turgor pressure

what is turgor pressure

pressure that forces the cytoplasm and cell membrane against the cell wall causing the cell to become rigid

what environment is turgor pressure maintained in

hypotonic environment

turgor pressure is lost in a ________ environment causing the cell to wilt

hypertonic

why does the cell wilt in a hypertonic environment

because the cell membrane pulls away from the cell wall in plasmolysis (cell shrinkage)

what are euglena and paramecium to their environment

hypertonic and their environment is hypotonic

what way does the water flow in the euglena

into the euglena

to prevent bursting of the cell euglena use a organelle called the ______

contractile vacuole

what is the contractile vacuole

an organelle that acts as a pump that squeezes excess water out of the cell to prevent lysis (bursting)

facilitated diffusion

diffusion of molecules that are charged or too large to pass through the cell membrane so they need help from a transport protein

transport protein

a helper for larger substances to pass through the membrane

channel protein

protein that forms a permanent pore/channel for certain ions to pass in or out (ion channel)

carrier protein

protein in the cell membrane that changes its shape to allow charged or large particles into the cell

phagocytosis examples

bacteria "eater" by WBC; food for cell

what will a vesicle fuse with to digest the bacteria or food particle

lysosome

exocytosis

movement of a substance out of a cell using vesicles that fuse with the cell membrane

exocytosis is how ___ are secreted and how what type of cells communicate with each other

horomones/proteins; nerve cells

what organelle does the vesicle come from

golgi body