CELL MEMBRANE(also called plasma membrane)

Cell membranes are made mainly of ________________ & __________________ PHOSPHOLIPIDS PROTEINS

Outsideof cell

Insideof cell(cytoplasm)

Cellmembrane

Proteins

Proteinchannel Lipid bilayer

Carbohydratechains

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LIPID TAILS ARE HYDROPHOBIC

HYDROPHILIC

HYDROPHOBIC

Image by Riedell

Oil and water don’t mix!

Image from: http://employees.csbsju.edu/hjakubowski/classes/ch112/lipids/micbilayer.gif

PHOSPHOLIPID BILAYER

Image from: http://employees.csbsju.edu/hjakubowski/classes/ch112/lipids/micbilayer.gif

CELL MEMBRANE

Proteins that stick on the surface = _____________(either inside or outside of cell)

Proteins that stick INTO membrane = ________________(can go part way in or all the way through)

PERIPHERAL

INTEGRAL

Recognize “self”

GLYCOPROTEINS

GLYCOPROTEINS are PROTEINS with carbohydrates attached

Image from: http://faculty.clintoncc.suny.edu/faculty/Michael.Gregory/files/Bio%20101/Bio%20101%20Lectures/Membranes/membrane.htm

WHAT DOES IT DO?

Acts as a boundaryControls what enters and leaves cell

Images from: http://vilenski.org/science/safari/cellstructure/cellmembrane.html http://www.mccc.edu/~chorba/celldiagram.htm

Cell membranes MOVE!

Molecules in cell membranes are

constantly moving and changing

Click to See Fluidity

Animation from: http://www.sp.uconn.edu/~terry/images/anim/fluidmem.gif

CELL MEMBRANE (PLASMA MEMBRANE)

Made mainly of ____________________ and _________________HYDROPHOBIC “tails” of phospholipids make molecules line up as LIPID ________________ with POLAR heads facing _______ & NON-POLAR tails facing ________ Proteins attached to surface (inside or outside)= _____________Proteins stuck into membrane = ______________ (can go part way in or all the way through)

OTHER MOLECULES:• GLYCOPROTEINS (proteins with ___________attached)•STEROIDS (lipids)

Membranes are ____________________________________(=Semi-permeable) Allow certain molecules to pass through; but keep others

out

__________________ = gel-like material + organelles between nucleus and cell membrane

“recognize self”

phospholipids proteins

BILAYER outin

PeripheralIntegral

sugars

SELECTIVELY PERMEABLE

cytoplasm