3.  BIG biological molecules ◦ Made of smaller parts  Monomers  Carbon-based (organic) ◦ Carbohydrates ◦ Nucleic acids ◦ Proteins ◦ Lipids

4.  Structure: ◦ Glycerol head ◦ Fatty acid tail  Used for: ◦ Long term energy storage ◦ Insulation ◦ Major component of cell membranes ◦ Signaling molecules and hormones  Examples: ◦ Fats, oils, waxes  Found in: ◦ All the good tasting foods

6.  ALL cells have cell membranes for support and protection  All cells need to import and export molecules in order to function properly and maintain homeostasis

7. 1. Regulates passage of nutrients, wastes, gases, and water into and out of cell *Selectively permeable – “picky” about what passes 2. Separates the cell from the environment 3. Allows cells to communicate with other cells via receptors on the surface

8.  Made of a phospholipid bilayer ◦ Phosphate (hydrophilic) “head” ◦ Lipid (hydrophobic) “tail” Phospholipid bilayer

9.  Protein channels ◦ Allow large molecules to pass through Protein channels

10.  SOME SUBSTANCES, ARE SMALL ENOUGH TO MOVE THROUGH THE SPACES BETWEEN THE LIPIDS.  NAME 3 EXAMPLES.

11.  Receptor Protein (Carbohydrate Antennae) ◦ Receives messages from outside the cell ◦ Cell communication is key for homeostasis! Receptor Protein