Passive Transport: Diffusion & Osmosis

_______ is the movement of molecules from an area of HIGH concentration to an area of LOW concentration.

Diffusion

______, ___-_____ molecules (i.e. O2, CO2) that can cross the membrane ON THEIR OWN move by means of DIFFUSION.

small, non-polar

________ is DIFFUSION of water through a selectively permeable membrane; polarity (dipole moment) is small enough where it can cross the membrane—to an extent—on its own.

Osmosis

What are the THREE OSMOTIC relationships?

1) Hypotonic 2) Isotonic 3) Hypertonic

An ________ solution is a solution that has the SAME concentration of water relative to solute IN and OUTSIDE of the cell.

isotonic

A ________ solution has a HIGH concentration of water and LOW solute INSIDE the cell.

hypotonic

____ _____ PREVENTS cell from bursting during hypotonicity.

cell wall

Cells LACKING a cell wall in a HYPOTONIC environment will begin to _____; this is called ______ ____; the cell bursts and dies.

swell, osmotic lysis

A _________ solution has a HIGH CONCENTRATION of SOLUTE on the INSIDE of the cell and a LOW concentration of water INSIDE.

hypertonic

Cells WITH a cell wall when placed in HYPERTONIC solution cause the cell to _____ and detach from the cell wall. This process is called ___________. When placed back into an ISOTONIC solution it could still survive.

shrink, plasmolysis

Cells LACKING a cell wall when placed in a HYPERTONIC solution cause the cell to _____, but could still survive when put back in an ISOTONIC environment.

shrink

In HYPOTONIC conditions, some organisms have a ___ ____ (i.e. bacteria) that protects them from bursting; _____ in the membrane or _____ _______ (i.e. in Amoeba) move excess water out of the cell in those WITHOUT a cell wall.

cell wall, sterols, water vacuoles

In HYPERTONIC conditions, some organisms ______ salt to make their cells isotonic with the environment PREVENTING swelling.

absorb

_____, _____, or _______ molecules are UNABLE to cross the membrane on their own—they need CARRIER PROTEINS.

large, polar, charged

Carrier proteins have ____ in the shape of that molecule that open and allow for passage.

pores

_________ ________ is the movement of molecules DOWN their concentration gradient but CANNOT cross the membrane on their own.

Facilitated diffusion

Does Osmosis, Simple Diffusion, and Facilitated Diffusion require energy?

no