Date post: | 18-Jan-2016 |
Category: |
Documents |
Upload: | alan-banks |
View: | 223 times |
Download: | 0 times |
Lipids & Cell Membranes
Honors Biology
Recall: Macromolecules
BIG biological molecules◦ Made of smaller
parts Monomers
Carbon-based (organic)◦ Carbohydrates◦ Nucleic acids◦ Proteins◦ Lipids
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
Lipids
Cell Membranes
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
Cellular Biology Review
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 environment3. Allow cells to communicate with other
cells via receptors on the surface
Cell Membrane Function: Homeostasis!
Cell membranes are fluid mosaics of lipids and proteins
Made of phospholipid bilayer ◦ Phosphate (hydrophilic) “head” ◦ Lipid (hydrophobic) “tail”
Structure of the Cell Membrane
Phospholipid bilayer
Channel protein◦ Allow large molecules to pass through
Structure of the Cell Membrane
Protein channels
Receptor Protein ◦ Receives messages from outside the cell◦ Cell communication is key for homeostasis!
Structure of the Cell Membrane
Receptor Protein
Cholesterol ◦ Lipids that prevent freezing◦ Helps membrane remain fluid (flexible)
Structure of the Cell Membrane
Cholesterol