1. Cellular Processes and structure
03 Cell Structure
Osmosis
Cell Membrane
Membrane Transport
Eukaryotic cells

2. Cell Membrane AP Bio Framework: 2.A.2 Holtzclaw: 50-52 (7.1-7.2)
Campbell:

3. Cells create and maintain internal environments that are different from their external environments.
Cell membranes are selectively permeable due to their structure.

4. Cell membranes separate the internal environment from the external environment

6. Selective permeability is a direct consequence of membrane structure
Fluid mosaic model - phospholipids slide around each other and are embedded with proteins

7. Selective permeability is a direct consequence of membrane structure
Reactions in organelles are separated from the rest of the cell - which is separated from the rest of the environment - by a permeable membrane.

8. Cell membranes Structural framework phospholipid molecules
glycerol attached to a phosphate and two carbon chains
amphipathic
embedded proteins
can span membrane or face one side
cholesterol
adds structure, determines fluidity
glycoproteins and glycolipids
carbohydrate bound to a protein (or lipid)
uses include signaling, structure, and protection

9. Cell membranes Structural framework phospholipid molecules
embedded proteins
cholesterol
glycoproteins and glycolipids

10. Phospholipids are amphipathic
Hydrophilic and hydrophobic ends.
Hydrophilic phosphates face the aqueous environments (internal and external)
Hydrophobic fatty acid portions face each other within the interior of the membrane itself.

11. Embedded proteins can be hydrophilic, or hydrophobic
charged and polar side groups
or hydrophobic
nonpolar side groups.

12. Cell membranes are selectively permeable
Small, uncharged or nonpolar molecules
freely pass across the membrane
N2, O2
Hydrophilic substances
embedded channel and transport proteins
large polar molecules and ions
glucose, Na ions
Water moves across membranes through channel proteins called aquaporins.

13. Cell walls provide a structural boundary
permeability barrier for some substances

14. Plant cell walls
Made of cellulose
external to the cell membrane

15. Prokaryote cell walls Made of Peptidoglycan
mesh of amino acids and sugars
external to the cell membrane

16. Fungal cell walls
Made of chitin
external to the cell membrane

17. Be able to
2.10 Use representations and models to pose scientific questions about the properties of cell membranes and selective permeability based on molecular structure.
2.11 Construct models that connect the movement of molecules across membranes with membrane structure and function