Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
42 Cards in this Set
- Front
- Back
|
Cell membranes
|
Selectively permeable.
Provide protection. House receptor. Provide sites for transport. Organize life processes. |
|
|
Cell membranes
|
Consist mostly of a phospholipid bilayer with protein molecules.
|
|
|
Phospholipid
|
phosphate group and 2 fatty acids bonded to 3 carbon glycerol.
|
|
|
Phospholipid
|
Has a hydrophilic head, and hydrophobic tail.
|
|
|
Amphipathic
|
Molecules with hydrophobic and hydrophilic regions.
|
|
|
(Amphipathic)Phospholipid
|
Self-assemble into a double-layered sheet.
|
|
|
Hydrophobic Tails
|
Core
|
|
|
Hydrophilic phosphate groups
|
Both surfaces.
|
|
|
Fuid Mosaic Model
|
Variety of molecules, carbs/proteins that form the membrane and move freely through it.
|
|
|
Cell Membranes Consist Of
|
Proteins, Cholestrol, Carbs, and phospholipids.
|
|
|
Selectively Permeable
|
Proteins function as pores. Membrane bound proteins promote movement of ions/molecules in or out of cells.
|
|
|
For a cell or organelle to function properly:
|
Membranes must be physically/chemically complete.
|
|
|
What ions must routinely move across cell membranes?
|
Lipid soluble molecules ie.oxygen, small uncharged polar ie.carbon dioxide and water.
|
|
|
How could membranes promote the movement of ions out of or into cells?
|
Membrane bound proteins.
|
|
|
How could membranes restrict the movement of ions out of or into cells?
|
Phospholipid bilayer.
|
|
|
Could a cell survive without an intact cell membrane?
|
No, because barrier to simple diffusion.
|
|
|
Permeability
|
Depends on solubility and size of molecules.
|
|
|
Betacynin
|
Reddish pigment located in large central vacuoles of cells.
|
|
|
Tonoplast
|
Vacuolar membrane.
|
|
|
High Temps
|
Cause molecular collisions that destroy membranes.
|
|
|
Selectively Permeable
|
Proteins function as pores. Membrane bound proteins promote movement of ions/molecules in or out of cells.
|
|
|
For a cell or organelle to function properly:
|
Membranes must be physically/chemically complete.
|
|
|
What ions must routinely move across cell membranes?
|
Lipid soluble molecules ie.oxygen, small uncharged polar ie.carbon dioxide and water.
|
|
|
How could membranes promote the movement of ions out of or into cells?
|
Membrane bound proteins.
|
|
|
How could membranes restrict the movement of ions out of or into cells?
|
Phospholipid bilayer.
|
|
|
Could a cell survive without an intact cell membrane?
|
No, because barrier to simple diffusion.
|
|
|
Permeability
|
Depends on solubility and size of molecules.
|
|
|
Betacynin
|
Reddish pigment located in large central vacuoles of cells.
|
|
|
Tonoplast
|
Vacuolar membrane.
|
|
|
High Temps
|
Cause molecular collisions that destroy membranes.
|
|
|
Freezing Temps
|
Cause water to crystallize and expand because of hydrogen bond alignment-ruptures membranes.
|
|
|
Which temp. damaged membranes the most? The least? How do you know?
|
-5C/most,20C/least. Because of color of water.
|
|
|
What is more damaging to membranes? Why?
|
Extreme cold, because water molecules expand and rupture membrane.
|
|
|
Why does freezing temp. require more time?
|
Water expands when it freezes because it needs more time for hydrogen bond alignment.
|
|
|
Organic solvents
|
Dissolve a membrane's lipids.
|
|
|
Acetone
|
Has the greatest ability to dissolve lipids. Damages membranes the most.
|
|
|
Are lipids soluble in both acetone and methanol?
|
Yes.
|
|
|
What damages membranes more?
|
50% Methanol.
|
|
|
Which solvent are lipids more soluble?
|
Acetone.
|
|
|
Did the highest concentration of both solvents cause the most damage?
|
Yes.
|
|
|
What other solvents might be interesting to test in this experiment?
|
Bleach, amonia, vinegar.
|
|
|
What was the purpose of tube7?
|
Control.
|
