Cell Membrane

Review Questions

• What three things make up a phospholipid? Draw and label where the 3 things are located.

• Draw a section of the cell membrane: where are the hydrophilic and hydrophobic regions?

• What makes something hydrophilic or hydrophobic?

Unsaturated Fatty Acid Tails

• Tails are bent (unsaturated) causing fluidity • Membranes solidify when they get cold• Membranes with unsaturated phospholipid

tails solidify at a lower temperature• Organisms adapted to cold climates have

more unsaturated phospholipid tails

Semi-Permeable

You Shall Not Pass

• Can Easily pass through– Small, uncharged, non-polar

• Cannot easily pass through– Big, charged, polar (bear)

“Fluid Mosaic Model”

• Phospholipid bilayer with many “floating” parts

Transport Proteins

• Channel Proteins

• Gated Channels

• Receptor Proteins