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Cell Membrane Unit D
Terms in this set (26)
Polar, phosphate-containing (polar-molecules); hydrophilic "water-lover"; face opposite of eachother.
Phospholipid Bi-layer (heads)
Non-polar fatty acid; hydrophobic "water-hater", face eachother in membrane's interior; mono-layer on each side.
Phospholipid Bi-layer (tails)
Dynamic - molecules move sideways; self-sealing (helps keep cell components inside); basic framework of plasma membrane.
Embedded in phospholipid bi-layer among fatty-acid tails; move from one location to another in membrane; minute channels through which substqances are transported in & out of cell; water soluble; selective - move potassium & sodium into cell; can recognize foreign cells; attach to hormones.
Loosley bound to membrane surface; easily separated.
Cellular respiration help support membrane; cholesterol makes cell membrane stronger; encloses cellular contents; facilitates contact with other cells & substances; provides receptors for chemicals (hormones); serve as neuro-transmitters; selectively permeable.
Physiology of Plasma Membrane
Size of molecules (small to medium uncharged polar molecules); solubility in lipids (oxygen & carbon dioxide & hormones can move thru easily); carrier molecules (integral proteins); glucose combines with insulin molecule to move into cells; increase permeability - water attracted to phosphates; very selective.
No energy required; depends on kinetic energy of molecules; movement down concentration gradient (high concentration to low concentration).
Passive (physical) process
Cell uses energy (ATP) in moving substances across membrane; movement against concentration gradient (low concentration to high concentration). "Pumps" a substance across a plasma membrane.
Active (physiological) processes
No energy; simple diffusion; osmosis (water); filtration; dialysis; movement of oxygen to cells (simple); helps larger materials move thru cell (facilitated). (Diffusion, osmosis, filtration, faculative diffusion, dialysis)
Temperature (heat-faster rate); Mass (the larger, the slower to move); Surface Area (faster diffusion); Distance (greater the distance the slower).
Hypertonic; Isotonic; Hypotonic.
Concentration of water & solute in fluid outside cell equals concentration of water & fluid inside cell; .9% Sodium Chloride is isotonic for red blood cells; no movement of water; maintains shape of cell.
Lower concentration of solutes; higher concentration of water outside cell; distilled water - very high; net movement of water into cells; cells swell & burst; moves from higher to lower; anything less than .9%.
Higher concentration of solutes, lower concentration of water outside cell; 10% sodium chloride compared to RBC; net movement of water out of cells; cells shrink; dehydration; anything above .9%.
Destruction of hemoglobin.
Any cell placed in water with no solutes.
Destruction of Red Blood Cells
Dependent on concentration gradient; pressure differences; molecules small to medium; kidneys (nephrons).
Cell membrane will enclose solid particles, will form vacuole. (active process)
"Cell-eating" (large cells) (active process)
"Cell-drinking" (active process)
Packaged by Golgi - pinched off, then to cytoplasm; opposite of diffusion; carrier molecules. (active process)
The movement of water molecules across a partially-permeable membrane down a water potential gradient; low-solute concentration to high-solute concentration; a passive process - does not need energy; solutions: isotonic, hypotonic, hypertonic).
Endocytosis & Exocytosis is an example of what type of cell transport?
Occurs only when a membrane is permeable to water but is not permeable to certain solutions.
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