molecular transport
ABC transporter
48 different types of ABC's found in humans, mutations in ABC's results in disease, requires ATP energy, moves against concentration gradient. 1. solute- binding protein interacts with solute. 2. complex interacts with channel. 3. channel undergoes conformational change. 4. ATP hydrolysis provides energy for opening channels and movement of solute
how many sodium and potassium would be moved to the appropriate locations if 3 ATP are used?
9 sodium out, 6 potassium in
explain the difference between active and passive transport. Give an example of active and passive transport and state 1) what is being transported, 2) with or against the concentration gradient, 3) is ut a channel or carrier protein or NA
Active transport is when ATP is used in order to move across the membrane, where as passive transport does not require direct energy to move across the membrane. Active transport: sodium potassium pump moves three sodium ions out of the cell and moves two potassium ions into the cell. the pump works against the concentration gradient and is an example of a carrier protein. Passive transport: passive transport moves with the concentration gradient and is a channel.
glucose transporters
a carrier protein that permits simple diffusion of glucose into the cell
resting membrane potential
a resting cell has a charge separation resulting in a positive charge on the extracellular site of the membrane and negative charge on the cytosolic side
porins
a type of transmembrane channel protein, formed by barrel structure, consists of B-pleated sheets.
aquaporin
a water channel, rapid transport of water molecules, 1 billion molecules/per second, only water can pass through
if the concentration of phosphate is the cytosol is 2.0 mM and the concentration of phosphate in the surrounding fluid is 0.1 mM, how could the cell increase the concentration of phosphate in the cytosol?
active transport
cotransport system
active. indirectly provides energy for active transport, requires ATP energy for proton pump not co transport , moves against concentration gradient, facilitated diffusion.
proton pump
active. stores energy in the form of voltage using protons, requires ATP energy, moves against concentration gradient.
sodium potassium pump
active. uses ATP to pump sodium ions out and potassium ions in. 3NA+ out, 2 K+ in, uses 1 ATP
membrane permeability
biological membrane is a selective barrier. permeable; small molecules, nonpolar/hydrophobic. Imperpermiable; large molecules, polar/hydrophilic.
the phosphate transport system in bacteria imports phosphate into the cell even when the concentration of phosphate outside the cell is much lower than the cytoplasmic phosphate concentration. phosphate import depends on a PH gradient across the membrane ( more acidic outside the cell than inside the cell). phosphate transport is an example of __________.
contransport
osmotic pressure
determined by the concentration of solutes present in solution
active transport moves solutes from areas of high concentration to areas of low concentration and requires ATP
false
endocytosis
forms vesicles from inward folding of the plasma membrane, decreases the surface area of the plasma membrane
ionotropic receptor
ligand gated channel proteins that respond to neurotransmitters to permit passage of ions. extracellular
the voltage across a membrane is called the ______.
membrane potential
a sodium- potassium pump _______
move three sodium ions out of a cell and two potassium ions into a cell while consuming an ATP for each cycle.
passive transport
moves from high to low concentration, doesn't require energy (ATP)
active transport
moving against the gradient- requires energy. ( ABC transporters, sodium- potassium pump, proton pump, H+ sucrose, cotransporter, endo/exocytosis)
simple diffusion
net movement of a substance down its concentration gradient, doesn't require energy, high --> low concentration, movement of a solute
isotonic
normal state for animal cells. flaccid state for plant cell, causing it to wilt.
voltage gated channel
passive
osmosis
passive. A derivation of simple diffusion where water moves instead of the solute, water follows solute.
facilitated diffusion
passive. specific transport proteins move solutes across a membrane, down the gradient= no energy required
white blood cells engulf bacteria using _________
phagocytosis
the difference between pinocytosis and receptor-mediated endocytosis is that ______
pinocytosis is nonselective in the molecules it brings into the cell, whereas receptor- mediated endocytosis offers more selectivity.
facilitated diffusion
process by which substances are transported across cell membranes by protein carrier molecules.
osmoregulation
regulation of osmotic pressure is required to prevent damage to cells
both endocytosis and exocytosis
requires cellular energy, transported substances never physically cross the plasma membrane
exocytosis
secreted large molecules out of the cell, requires fusion of vesicles with the plasma membrane, increases the surface area of the plasma membrane
hypertonic
shriveled cell for animal cells, plasmolyzed and not rigid cell wall for plant cell
passive diffusion is either _____________
simple diffusion- like osmosis. or facilitated diffusion- channel (voltage gated, ligand gated, or mechanically gated) or carrier ( glut 1 transporter.
gated channels
solutes can pass through channels only when in OPEN conformation, determines by their response to stimuli listed below: voltage gated, ligand gated (either intracellular or extracellular), and mechanically gated.
diffusion
substances pass without an intermediary
the force driving simple diffusion is ______, while the energy source for active transport is _______.
the concentration gradient; ATP
cotransport
the energy required to move one solute against its concentration or electrochemical gradient is provided by an ion movement into the cell down its electrochemical gradient
hypotonic
water rushes into animal cells causing it to swell. We want this excess water in plant cells.
