movement through the cell membrance {osmosis and defusion) Flashcards
Substances move in and out of cells in 2 ways
Diffusion
Active Transport
Diffusion
movement of molecules from a region of higher concentration to a
region of lower concentration.
Active Transport
Movement of molecules from a less crowded to a more crowded
area WITH the use of energy.
Molecules are “carried” into or out of the cell using some of the cell’s
energy.
Membranes can be
Permeable
Semi Permeable
Impermeable
Permeable
let everything in and out
Semi Permeable
let some things in and out
Impermeable
let nothing in and out
Biological membranes
are selectively permeable Cells have special mechanisms to allow substances which cannot pass through the membrane to enter the cell when necessary
Diffusion
the spreading of molecules from an area of high concentration to an area of low concentration
Osmosis
the movement of water across
a semi-permeable membrane from a
region of low concentration to a
region of high concentration
does osmosis require energy
Osmosis is a special type of diffusion that
does not require energy
how is osmosis
Osmosis is passive
what are animal cells enclosed by
Animal cells are only
enclosed by a
membrane
what is the function of our kidneys
It is the function of our kidneys to make
sure the fluid in our bodies that surrounds
our cells (plasma) has a stable
concentration
Amoeba
a single celled organism that
lives in freshwater
what is less concentrated, fresh water or amoeba
fresh water
what does the Osmoreregulation system in amoeba
consists of
a contractile vacuole
what does the contractile vacuole do
expels water
which prevents the cell from bursting
If a plant cell is surrounded by a less
concentrated solution,
water from outside
will move into the cytoplasm and vacuole of
plant cells
how do roots absorb water
through osmosis
Water entering roots by osmosis
The water outside is less concentrated
than the water in the cytoplasm
Turgor
When the outside water enters the plant cell, the vacuole becomes bigger and the cytoplasm swells This causes the membrane to be pushed out towards the cell wall
Turgid
When cells are fully “swelled” with the membranes pushing against the cell wall
what does turgor pressure do
gives plants their strength
what would happen if plants didn’t have turgor pressure
they would be wilted
If plant cells are surrounded by a more
concentrated solution
the water inside
the cell would move out to the more
concentrated solution outside
plasmolysis
The vacuole and cytoplasm shrivel and the cell membrane moves away from the cell wall The cell loses its turgor pressure
the most common causes
of food spoilage
Bacteria and Fungi
