Chapter 8 Cell Environment (Bio H)

Substances move in and out of the cell to maintain _______________.

Homeostasis

cell membrane regulates what _________ or _________ the cell

enters or leaves

Diffusion

Movement of molecules from an area of higher concentration to an area of lesser concentration.

diffusion continues until concentration of molecules is ________ on both sides of the ___________ = ____________

equal, membrane = equilibrium

___________, _____________, and ________ affect the rate of diffusion

temperature, concentration, and pressure

_________ the temperature, concentration and pressure, the ____________ the rate of diffusion

higher, faster

Osmosis

the diffusion of water across a selectively permeable membrane

Turgor Pressure

pressure built up inside plant cell when water moves in; plant becomes stiff, without it the plant would wilt

Contractile Vacuole

organelle found in freshwater unicellular organisms; since water is constantly flowing in, it acts as a pump to push water out

Plasmolysis

occurs when the cell shrinks due to water leaving the cell

Cytolysis

bursting of the cell when they take in too much

What are the other kinds of transport?

Facilitated Diffusion, Active Transport, Endocytosis, and Exocytosis

Facilitated Diffusion

movement of specific molecule through protein channels in the cell membrane

Active Transport

movement of substance form an area of low to high concentration; opposite of diffusion, requires energy

What is endocytosis?

A process in which cells engulf substances too large to pass through the cell membrane by means of pockets (infoldings) of the cell membrane.

What is phagocytosis?

A type of endocytosis where the substance being engulfed is solid.

exocytosis

removal of large molecules to the outside of the cell by fusion to the cell membrane; ”dumped”

What are the kinds of solutions?

Isotonic, Hypotonic, and Hypertonic

Isotonic

is in equilibrium- no net movement: molecules equal inside and outside the cell

Hyopotonic

surrounding solution has lower solute concentration than inside the cell-cytolysis occurs (cell in distilled water)

Hypertonic

surrounding solution has higher solute concentration than inside cell-plasmolysis occurs (cell in salt water)

water always moves from a _________ solution to a __________ solution

hypotonic, hypertonic