Cell Membrane Maintains homeostasis by regulating the movement of molecules in and out of the cell.

Cell MembraneMaintains homeostasis by regulating the movement of molecules in

and out of the cell

Fluid Mosaic Model

• Polar heads are orientated to the aqueous solution (inside and outside of cell)

• Non polar tails are orientated towards one another

• Integral proteins are embedded to form a mosaic

Membrane Proteins

• Channel Proteins (transport)• Carrier Proteins (transport)• Receptor Proteins (signal transduction)• Cell Recognition Proteins (glycoprotein)• Enzymatic Proteins• Intercellular Joining• Attachment for Cytoskeleton

Membrane Permeability

• Impermeable• Permeable• Differentially/Selectively Permeable

Terms to know

• Osmotic pressure• Turgor Pressure• Tonicity• Isotonic• Hypotonic• Hypertonic• Plasmolysis• Creanation

Methods of Transport Across The Cell Membrane

Passive Transport

Rate of Diffusion

• Temperature increase• Increased concentration gradient• Increased membrane permeability• Smaller molecule size

Osmosis

• Diffusion of water through a semi permeable membrane

Facilitated Transport

• Movement of molecules along the concentration gradient with the aid of carrier proteins

Active Transport

• Movement of molecules against the concentration gradient using carrier proteins and ATP

Active Transport

• Endocytosis– Phagocytosis– Pinocytosis

• Exocytosis

Animation Review