Cell Membrane

Cell Membrane? Location?  _______________ the cell Function? 1._______________ and __________ for the cell 2.Regulation of what ________ and _________ the cell WHY? -Essential in order to maintain *homeostasis within the cell *maintaining _________ internal conditions

Composition of Cell Membrane  Phospholipid Bilayer 1._______________:  Hydrophilic Head; “water-_________”  Hydrophobic Tail; “water-_________” 2.Bilayer  _______-layers (of phospholipids)

Composition of Cell Membrane  ___________ embedded throughout phospholipid bilayer  Integral Proteins: ______ the width of the cell membrane  ___________ Proteins: Located on one side of the cell membrane (or on the ‘periphery’)  A variety of different ________ of proteins within the cell membrane, each with different ___________

Composition  ______________: another lipid that maintains the _____________ stability of the cell membrane  Carbohydrates: allow for cell-to- cell ______________; a “fingerprint” for each cell  Allows for the immune system to recognize ‘foreign’ cells and attack them  Attached to proteins or phospholipids on __________ layer of cell membrane

 Break it down:  FLUID: The cell membrane is ___________ ________ due to the lipid “tails” on its interior; they “wiggle”  This means that the cell membrane is pliable  The cell membrane has the consistency of olive oil at body temp.  MOSAIC: __________________ of different types, ________________ positioned throughout the membrane create a “mosaic” appearance The cell membrane is a constantly moving assemblage of parts. Fluid Mosaic Model

 Transport of molecules from one side of the membrane to the other in order to maintain homeostasis within the cell.  _____________ Permeable: Only _________ substances can move across the membrane while others cannot.  _________, non-charged molecules (H20, CO2, O2, etc.) can ________ cross the cell membrane.  This is referred to as Passive Transport: molecules are ‘freely’ or ‘passively’ traveling through the cell membrane  This occurs through one of two ways: ___________ or ____________ diffusion Cell Membrane Function

Passive Transport: Diffusion  No ____________ is required  Diffusion: the movement of molecules from a __________ concentration to a _________ concentration until equilibrium is reached  Concentration: the amount of solute in the solvent  ___________: dissolved substance (in the solvent)  solvent: the liquid containing the dissolved substance  Equilibrium: occurs when the __________ concentration is the same throughout the system; ___________ on both sides of the membrane

 A form of Passive Transport (so no _________ required)  Facilitated Diffusion: ____________ molecules (that are unable to passively cross the cell membrane) are “carried” through via a channel protein.  Specific protein channels carry specific types of molecules  For example: __________ is transported across the cell membrane via facilitated diffusion Passive Transport: Facilitated Diffusion