1. Honors Biology

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

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

5.  All cells have cell membranes  Some cells (eukaryotes) have membranes surrounding organelles ◦ Example: nucleus  All cells need to import and export molecules in order to function properly and maintain homeostasis

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

7. Cell membranes are fluid mosaics of lipids and proteins

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

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

10.  Receptor Protein ◦ Receives messages from outside the cell ◦ Cell communication is key for homeostasis! Receptor Protein

11.  Cholesterol ◦ Lipids that prevent freezing ◦ Helps membrane remain fluid (flexible) Cholesterol