Term
| What are the types of cellular transport? |
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Definition
Passive and Active
1) passive - facilitated diffusion, osmosis, simple diffusion
2) active - primary active trasnsport (Na+/K+ ATPase pump) |
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Term
passive transport
movement of what?
concentration gradient? |
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Definition
does not require ATP
-movement of solutes from an area of HIGHER concentration to LOWER
-move DOWN a concentration gradient |
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Term
simple diffusion
rate of diffusion with temperature?
rate of diffusion with molecular size? |
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Definition
type of passive transport
-rate of diffusion INCREASES as temp. INCREASES
-rate of diffusion DECREASES as molecule size INCREASES |
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Term
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Definition
type of passive transport
-diffusing substance binds with CARRIER protein on the inner or outer surface of plasma protein)
-binding causes a conformational change in carrier protein: it flips upside down
-after changes, substance is then released into intra/extracellular fluid |
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Term
Osmosis
terms of solutions across a membrane? |
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Definition
type of passive transport
-the movement of WATER from an area where there are LESS solutes to where there are MORE solutes.
-terms: hypertonic, hypotonic, isotonic
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Term
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Definition
| the solution with more solutes "more salt" |
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Term
hypotonic
how does water move? |
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Definition
the solution with less solute particles
-water will always move from a hypotonic solution to a hypertonic solution |
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Term
| suppose a cell with 5 g NaCl is dropped into a beaker containing 15 g NaCl. Which solution is hypertonic? hypotonic? where will water go? |
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Definition
-beaker is hypertonic
-cell is hypotonic
-water will move out of the cell into the beaker
-cell will shrink (crenate) |
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Term
| in facilitated diffusion, what type of proteins are used as carrier proteins? |
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Definition
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Term
Suppose a cell with 11 g NaCl is dropped into a beaker that contains 11 g NaCl.
Which solution is hypertonic?
hypotonic?
where will water go? |
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Definition
-the 2 solutions are isotonic
-no osmosis will occur, no movement of water |
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Term
Active transport
concentration gradient? |
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Definition
requires ATP and involves movement of solutes from an area of LOWER concentration to HIGHER
-solutes move UP or AGAINST the concentration gradient |
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Term
| How does the K+/Na+ ATpase pump move the ions against their concentration gradient? |
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Definition
through energy derived from enzymatically splitting ATP into ADP and an inorganic phosphate group
-this splitting releases energy |
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Term
There is there more Na+? k+?
Where does the pump move them? how many? |
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Definition
More Na+ outside the cell and more K+ inside the cell
-the pump moves 3Na+ outside the cell toward a HIGHER Na+ concentration
-the pump moves 2K+ inside the cell toward a higher K+ concentration |
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Term
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Definition
the generation of "voltage" (energy) in the form of electricity by the separation of oppositely charged particles across the membrane
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Term
resting membrane potential
what is the usual RMP?
why is this value negative? |
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Definition
the charge on an excitable nerve/muscle cell's membrane when it is at REST (inactive)
-90 mv to -70 mv
-negative because the intracellular fluid is more negative than extracellular fluid
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Term
| At rest, is the cell polarized or non-polarized? |
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Definition
| polarized (due to separation of charges) |
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Term
| Why is the inside of the cell negative? |
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Definition
1) at rest, the membrane is more permeable to K+ than to Na+
2) due to large concentration of intracellular negatively charged proteins that are IMPERMEABLE
3) lots of K+ moves passively out of cell because of its ion channel, taking the + with it |
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Term
| At rest, where does the Na+ go? |
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Definition
| a little Na+ moves passively into cell because of its ion channel (but not as much as K+ leaves cell) |
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Term
| How is K+ and Na+ kept at an equilibrium? |
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Definition
| the passive and active movements occur simultaneously (at the same time) |
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Term
| What are the 3 main roles of the Na+/k+ ATPase pump? |
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Definition
1) actively kicks some Na+ out of cell
2) actively pulls some in K+ to inside the cell
3) maintains differential concentration gradients for Na+ and K+ (they STORE ENERGY for nerve and muscle cell formation) |
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