Finals: CELLULAR TRANSPORT Flashcards
-diffusion:
tendency for particles of any kind to spread out evenly in an available space moving from where they are more concentrated to less concentrated, requires no work, result from thermal motion of atoms and molecules
-concentration gradient
increase or decrease in density of chemical substance in an area
-passive transport:
diffusion of a substance across a biological membrane,
-osmosis: d
diffusion of water molecules across a selectively permeable membrane, water moving from A to B (net force), aquarium allows water to go through simple diffusion
-polar and ions:
have difficulties moving through simple diffusion, not soluble
-selectively permeable membrane
allow some substances to cross more easily than others, hydrophobic interior = one reason for this,
-solute: s
substance that is dissolved in a solution
solution:
liquid consisting of a uniform mixture of two or more substances
aqueous solution
one which water is the solvent
hypertonic:
solution with a higher solute concentration, shrivel and can die from water loss
-hypotonic:
solution with a solute concentration lower than that of the cell, cell gains water, swells, and may burst like an overfilled balloon
-isotonic:
cell volume remains constant, solute concentration of a cell and its isotonic environment are essentially equal and cell gains water at the same rate that it loses
-what happens to plant in hypertonic:
shriveled, loses water, plasma membrane pulls away from cell wall
-what happens to plants in hypotoni
turgid, needs net inflow of water, elastic cell wall expands a bit, pressure it exerts prevents cell from taking in too much water and bursting
-what happens to animals in hypotonic:
: lysed
-what happens to animals in hypertonic:
shriveled
-plasmolysis
plant cell in hypertonic, cell loses water, shrivels, plasma membrane pulls away from cell wall, causes plant to wilt and can be lethal to cell and plant
turgor pressure
The pressure exerted by water inside the cell against the cell wall.When a plant cell stores ions, sugars and other solutes in its vacuole, this causes an influx of water. The influx of water results in a large turgor pressure exerted on the plantcell wall. This makes plant cells to become turgid, thus, helping the plants to stand upright, and do not wilt.
-protein channels:
create channels for things to move through, aquaporin, very selective, used for facilitated diffusion (no energy required)
-examples of protein channels:
sodium channel, potassium, glucose, Ca2+, amino acid
-sodium channel:
only sodium can go in
-potassium channel:
when it opens, only lets potassium out
-pumps:
involved with active transport, energy requirement
-membrane globular protein functions:
enzymes, signal transduction, transport, cell to cell recognition (fuzzy coat)
-transport:
protein channels and pumps
-facilitated diffusion:
when one of proteins channels makes it possible for a substance to move down its concentration gradient, type of passive transport (does not require energy), driving force is concentration gradient, greater to lesser
-active transport:
use pumps, substance moves up a concentration gradient, less to greater, energy needed (ATP)
-example of active transport
sodium potassium pump:
-down:
greater to lesse
-up:
lesser to greater
-exocytosis:
export bulky materials such as proteins or polysaccharides, transport vesicle filled with macromolecules buds with golgi apparatus and moves to plasma membrane, vesicle fuses with plasma membrane and vesicles contents spill out of cell while vesicle membrane become part of plasma membrane,
-endocytosis:
transport process opposite of exocytosis, cell takes in substance, depression in plasma membrane pinches in and forms a vesicle enclosing material that had been outside the cell
-pinocytosis:
cellular drinking, cell gulps droplets of fluid into tiny vesicle, not specific, takes in any and all solute dissolved in droplets TYPE OF ENDOCYTOSIS
-phagocytosis:
cellular eating, cell engulfs particle by wrapping extensions called pseudopodia around it, packing it within a membrane enclosed sac large enough to be called a vacuole TYPE OF ENDOCYTOSIS
-phospholipid:
hydrophilic head, hydrophobic tails, arrange themselves as a biolayer, in PM, tails want to be next to each other, two layers of phospholipids
-plasma membrane:
globular protein in bilayer
cellular secretion:
protein transport vesicle at RER, protein put in ER, it budds off RER and become transport vesicle, it attaches to golgi body and bleg, go through series of golgi body sacs, at the final sac it either become a lysosome or secretory vesicle, when it becomes a secretory vesicle = cellular secretion, it goes to the plasma membrane and export protein
EXO
lyososome
stay in cell
blebbing
come out of membrane
gylcolayx, fuzzy coat
involved with outer leaflet, made of glycoprotein and glycolipid, contract inabition (stop dividing)
how many ATP per glucose are the result of ETC in mitochondria
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