Download The Cell Membrane - Elgin Local Schools

The Cell Membrane
The Cell Membrane
-regulates what enters/leaves the cell
-semi-permeable
-composed of phospholipids and proteins
Phospholipids: has a hydrophilic head
and two hydrophobic tails.
-creates a bi-layer
Cell Transport: movement across the
cell membrane
Two Types
1. Passive Transport: movement without cell
energy (ATP)
2. Active Transport: movement with cell energy
(ATP)
Passive Transport
Concentration Gradient: a
difference in solute
concentration across a
membrane
Equilibrium: rate at which
molecules entering or
leaving becomes equal
Direction of Osmosis
Solute: solids dissolved in
water
Solvent: substance that
dissolves solute
Hypertonic solution:
solution with higher conc. of
solute
Hypotonic solution:
solution with lower conc. of
solute
Isotonic solution: equal
amounts of solute
Active Transport
- Uses Adenosine
Triphosphate (ATP) from
mitochondria
Active Transport
1. Endocytosis: cell takes
in materials
A. Phagocytosis:
endocytosis that
digest solid particles
(white blood cells)
B. Pinocytosis: takes
in small particles
2. Exocytosis: cells expel
materials
Cystic Fibrosis: Cell Transport Disease
-fatal genetic disease
-chloride ions accumulate
inside the cell
-water is drawn in
-thick mucous in lungs, liver,
digestive tract
-death by 30
-affects only humans of
white European Ancestry
-1/2000 births
-1/25 caucasian carry gene