Term
| the cell membrane is composed of what? |
|
Definition
| mostly of lipids and proteins |
|
|
Term
| what are 2 characteristics of the phospholipid bilayer? |
|
Definition
- 2 hydrophilic lipid heads facing opposite directions
- hydrophobic lipid tails sandwiched between |
|
|
Term
| Functions of of phospholipid bilayer? (3) |
|
Definition
- separates fluids inside cell from fluids outside
- regulates what gets in and what gets out
- helps maintain homeostasis at cell level |
|
|
Term
| what is semi-permeability (selective permeability) in regards to the cell membrane? |
|
Definition
| ability to regulate what goes in a out of the cell |
|
|
Term
| what is the currently accepted model of the cell membrane |
|
Definition
|
|
Term
| How and whether substances get through the cell membrane depends upon what 3 things: |
|
Definition
- size of molecule
- polarity
- electrical charge |
|
|
Term
T or F
Smaller molecules are more likely to get through the cell membrane |
|
Definition
|
|
Term
| T or F hydrophilics are more likely to get through the cell membrane |
|
Definition
|
|
Term
|
Definition
| the movement of a substance down its concentration gradient from more to less concentrated |
|
|
Term
|
Definition
| the diffusion of water across a selectively permeable membrane |
|
|
Term
| what are 3 examples of types o molecules are capable of diffusing through the cell membrane? |
|
Definition
- dissolved gases
- lipid soluble molecules
- sometimes water |
|
|
Term
| 2 reasons why some molecules not able to diffuse through the cell membrane? |
|
Definition
- too large
- hydrophobic molecules (repelled by water) |
|
|
Term
|
Definition
| moving from high concentration to low concentration |
|
|
Term
|
Definition
| comparison of solute concentration (hypo, hyper, iso) |
|
|
Term
| what are the 3 levels of tonicity? |
|
Definition
- hypotonic
- hypertonic
- isotonic |
|
|
Term
|
Definition
| higher concentration of solute |
|
|
Term
|
Definition
| lower concentration of solute |
|
|
Term
|
Definition
| equal concentration of solute |
|
|
Term
compare two solutions:
#1 is 80% Na Cl, 20% H20
#2 is 65% Na Cl, 35% H20
which solution is hypotonic?
hypertonic? |
|
Definition
- hypotonic = #2
- hypertonic = #1 |
|
|
Term
|
Definition
| when animal cells have shriveled and shrunk |
|
|
Term
|
Definition
| when animal cells fill and rupture |
|
|
Term
|
Definition
| plants that have enough water |
|
|
Term
|
Definition
| when plant is dehydrated and vacuole shrinks |
|
|
Term
| 2 characteristics of passive transport |
|
Definition
- requires no energy
- moves down the concentration gradient |
|
|
Term
T or F
water always moves from hyper to hypo tonicity |
|
Definition
|
|
Term
| 2 characteristics of facilitated diffusion |
|
Definition
- uses protein channels or carriers
- still uses concentration gradient |
|
|
Term
| 3 characteristics of active transport |
|
Definition
- requires energy (ATP)
- uses proteins
- goes AGAINST the concentration gradient (low to high) |
|
|
Term
| PUMP usually refers to what? |
|
Definition
| going against the concentration gradient |
|
|
Term
|
Definition
transportation in or out of a cell within a vesicle
(i.e., proteins, larger molecules) |
|
|
Term
|
Definition
|
|
Term
| physical action of endocytosis |
|
Definition
| plasma membrane engulfs & pinches off a "sac" or vesicle within the cell |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
| moving material out of a cell in a "sac" or vesicle (reverse of endocytosis) |
|
|
Term
| What are the two types of ENERGY-REQUIRING TRANSPORT? |
|
Definition
- active transport
- bulk transport |
|
|
Term
| What are the two types of PASSIVE TRANSPORT? |
|
Definition
- simple diffusion
- facilitated diffusion |
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