Selectively permeable- has a hydrophobic bilayer- allows hydrophobic molecules and small molecules like O2 can sneak between the membrane. Large hydrophilic molecules cannot pass through the membrane ie: glucose, sodium ions, hydrogen ions.
Separates interior and exterior of the cell
called cell membrane because it is the outermost coating of the cell
Forms the basic fabric of the membrane. Constructed of phospholipids which have a polar head that is charged and hydrophilic, they lie on the inner and outer surface of the membrane. It also has a uncharged nonpolar tail that is hydrophobic which lines up the center of the membrane.
maintains its spherical shape
allows them to reseal when torn
Tendency of molecules or ions to move from an area where they are in higher concentration to an area where they are in lower concentration. Can also be described as molecules moving down their concentration gradient.
Diffusion is based on concentration, collision, molecular size, and if a molecule is a lipid soluble molecule
Channel-mediated facilitated diffusion
Active transport (Solute pumps)
Phospholipids orient themselves in aqueous solutions such that: