Download The Plasma Membrane

Name ________________________________
THE PLASMA MEMBRANE
POWERPOINT NOTES
Period ________ Date ________ Seat ______
1. The plasma membrane is approximately _______ thick and is __________________ permeable.
2. Selectively permeable means that the _______________ is selective as to which substances can
_________ through them.
3. Cellular membranes are composed primarily of _________, ___________ and _____________.
4. Lipids are a family of compounds including _______, ________________ and _____________.
5. Lipids are __________________ in water.
6. Insoluble means that they don’t ____________ in water.
7. In a cell’s membrane, back to back ________________ molecules form _____ distinctive layers.
8. __________ is the main component inside and outside the cell.
9. ___________ is a term that means “watery.”
10. The outside of the cell is known as the _________________ side.
11. The inside of the cell is known as the _________________ side.
12. The two layers of the membrane together are known a phospholipid _______________.
13. The phosphate heads of the lipids are ________________.
14. hydrophilic means __________ _____________.
15. The two tails of the phospholipids are ___________________.
16. Hydrophobic means _________ _____________.
17. A phospholipid bilayer is __________________, meaning that it has both a hydrophilic region and
a hydrophobic region.
18. Phospholipids are the most _______________ lipids in most membranes.
19. Membrane phospholipids move laterally at a rate of _____________, which is the length of a
typical ______________ cell.
20. Phospholipids also make __________________ flip flops at a rate of about _______________.
21. Cell plasma membranes are usually about as fluid as _________ _______.
22. The bilayer also contains many molecules of the steroid _________________.
23. Cholesterol ___________ the movement of phospholipids in cell membranes.
24. At lower temperatures, however, cholesterol helps to keep the membrane from ____________.
25. Unsaturated hydrocarbon tails of the lipids cause _________ in the lipid bilayer.
26. Bilayers with kinks have __________ cholesterol molecules than those without kinks.
27. The fewer the number of cholesterol molecules, the more _________ the membrane.
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Name ________________________________
THE PLASMA MEMBRANE
POWERPOINT NOTES
Period ________ Date ________ Seat ______
28. Saturated hydrocarbons have ___________ tails.
29. The greater the number of cholesterol molecules, the more _____________ the membrane.
30. In addition to cholesterol, the membrane bilayer is also studded with _____________.
31. _____________ or internal proteins are embedded into the bilayer.
32. Proteins that span the entire bilayer are called ____________________ proteins.
33. Like the bilayer, internal proteins have _________________ and _______________ regions.
34. _____________ or peripheral proteins are not embedded.
35. Extrinsic proteins are ______________, or water loving.
36. Proteins are made up of chains of ___________ _______. The hydrophobic region of the chain is
usually shaped like a __________ or coil.
37. Examples of amino acids are ________________, _______________ and ________________.
38. The amino acids in the helix tend to be _____________________.
39. The amino acids on the ends of the chain tend to be _____________.
40. All amino acids have the following parts:
41. There are only ______ known different amino acids used in the making of proteins.
42. It is the _____ group that makes amino acids structurally different from one another.
43. The R group also determines the amino acid’s ______________.
44. An amino acid with _______ at the end of the R group is a hydrophilic and polar molecule.
45. An amino acid with a __________ group at the end of the R group is hydrophobic & nonpolar.
46. The phospholipids, steroids and proteins of the membrane form a __________ of substances
that float about. This is known as the _____________ _____________ _____________.
47. The fluid mosaic model was proposed by ______________ & ______________ in 1972.
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