B.4(B)
Everything you need to know about…
Homeostasis
Water
Nutrients
Extracellular space
(Outside the cell)
Membrane
Intracellular space
(Inside the cell)
Gases
Wastes
Cells must maintain a
steady balance of water,
nutrients and energy.
The cell membrane helps maintain
homeostasis by controlling what
enters and exits the cell.
Diffusion
Small, uncharged particles
move along their
concentration gradient from
high concentration to low
concentration through the
cell membrane
High
concentration
Low
concentration
Diffusion
does NOT
Facilitated Diffusion
require cells
to use energy!
High
concentration
Low
concentration
Proteins help move large and
charged particles from high
concentration to low
concentration across the cell
membrane
Osmosis
High
concentration
Osmosis is the diffusion
of water. Water moves
from high concentration
to low concentration
Low
concentration
Osmosis is always the
diffusion of WATER!
Plant
Cells
Hypertonic
Isotonic
Hypotonic
Red
blood
cells
Osmosis causes water to
enter or leave cells
Active Transport
Low
concentration
Cells use energy to move
particles against their
concentration gradient
from low concentration to
high concentration.
High
concentration
Active transport requires
cellular ENERGY in the
form of ATP!
Endoplasmic Reticulum
Endoplasmic
reticulum
The endoplasmic reticulum (ER) transports molecules to different
parts of the cell. It is like the circulatory system of the cell!
Vesicles
Vesicles are tiny packages of molecules that travel between
organelles and can transport molecules across membranes.