Transport Across a Cell Membrane Flashcards
symporter
couples the transport of two molecules to move glucose against its concentration gradient
the molecules move in the same direction
fenestrations
small windows in nephrons that allow passage of small molecules across the membrane
lowering temperature slows/speeds equilibrium
slows the equilibrium process by decreasing the kinetic energy
cholera
turns on the chlorine transporter in the intestine, so water goes out osmotically
potassium moves up/down the concentration gradient, up/down the membrane potential
up the concentration gradient, down the membrane potential
it goes toward an area of higher potassium concentration, but because there are anions inside the cell, it goes down the membrane potential
the plateau is around -92 mV (the equilibrium potential)
electric gradient and concentration
they can balance each other out, such at a cation can exist in high concentrations inside the cell if there is a negative charge inside
apical side
faces the lumen
rank the 4 types of cell movement by ATP use
- (highest) phagocytosis
- sodium/potassium pump
- symporter
- leaky channel
down the gradient
from high to low; requires no energy
antiporter
molecules go in opposite directions
sodium and glucose (symport)
sodium goes into the cell (it wants to go inside the cell) and helps glucose get into the cell
this is an example of symport
sodium and calcium in the heart
bring in sodium, pump calcium out (antiporter)
leaky channel
Potassium is generally higher inside the cell
Na is generally higher outside of the cell
“Special K in the house, Na I’m outside”
primary active transport
use of ATP to push something against its concentration gradient
secondary active transport
antiport: we want glucose to leave the cell into the blood stream, so we let Na+ inside and send glucose out (they go in opposite directions)
endocytosis/exocytosis
for something to go into a cell (uses a lot of energy) or to exit a cell (also uses a lot of energy)
endothelial cells
the cells lining the glomerulus of the afferent arterial in the kidney, which are fenistrated
facilitated diffusion
something has to facilitate the movement of polar molecules across the membrane; proteins like a chloride channel
diffusion
the process of moving from high to distributed, lower concentrations
hypertonic, hypotonic
high and low concentration
glomerulus
a loopy structure that accepts blood from the afferent artery, where filtration occurs
the Bowman’s capsule
where the filtrate comes out of the glomerulus (Bowman’s space)
basement membrane
another barrier between glomerulus and Bowman’s space
tubular cells
epithelial cell; podocytes that go into the basement membrane and endothelial cell
