cells (important!)

4. phospholipid bilayer with proteins
6. occludins in membranes of adjacent cells fuse together, forming mostly impermeable junctions that encircle each cell.
7. loosely attached to integral proteins. include cytoskeleton and extracellular matrix proteins, and motor proteins.
8. gelatinous composition of proteins & polysaccharides. organized mesh holding cells together
11. no energy input, down the gradient, with and without transport proteins
14. firmly inserted transmembrane proteins. include transporters, receptors and enzymes.
16. interstitial fluid, blood plasma, csf. act as transport and dissolving media.
17. electrical potential energy produced by separation of oppositely charged particles across the cell membrane in all cells.
19. only lets in nonpolar molecules and small polar molecules.
20. polar heads, non-polar fatty acid tails. inner and outer membrane surfaces. 75% of membrane lipids.
22. two parts arise from cytoplasmic plaques. intermediate (keratin) filaments. linker (cadherin) proteins.
23. outer surface of the cell. separates intracellular from extracellular.

1. glycocalyx, wavy shape of cell membranes, cell junctions
2. abundant proteins w/sugar groups. cell to cell interactions and cell to cell recongition.
3. hydrocarbon rings are between phospholipid tails. stabilizes the membrane, and promotes membrane fluidity. 20% of membrane lipids.
5. contents between membrane and nucleus. have distinct jobs for the cell
9. energy(atp) required, against the gradient. WITH transport proteins.
10. (communication nexus) membranes of adjacent cells are very close and connected by connexions
12. intestinal/gastric juices, saliva, mucus, etc. aid in lubrication and digestion.
13. largest organelle. contains most of the genetic material.
15. polar sugar groups, and non-polar fatty acids. only on outer membrane surface. 5% of membrane lipids
18. difference in electrical charge between two points
21. recipe for fluids inside and outside the cell membrane are different.