Download Membranes organize a cell`s activities

Membranes organize a
cell’s activities
Ch. 6.2
► Plasma
membrane acts as a cell’s boundary
► Regulates the traffic of chemicals that go in
and out of the cell
Membrane Structure
► Acts
as a partition
► Allows certain substances to pass in and out
to the cell
► Made
of proteins and lipids
 PHOSPHOLIPID  2 fatty acids
►The
tail is HYDROPHOBIC
►The head is HYDROPHILIC
► Also
includes a phosphate (PO4-3) group
► Helps
form boundaries btwn 2 watery
environments
 Separates cytoplasm from the surrounding of a
cell
► Sandwich
of the phospholipids called a
PHOSPHOLIPID BILAYER
The Many Functions of Membrane
Proteins
► Proteins
perform most of the membrane’s
functions
 Helps carry out chem. rxns
 Helps cells communicate and recognize each
other
 Helps move substances across the membrane in
and out of the cell
Concept Check
► Describe
how phospholipid molecules are
oriented in the plasma membrane of a cell.
► What is the function of a transport protein?