test1: ch6 Flashcards
cell membrane is _________ ________ which means it only allows certain molecules through
selectively permeable
type of transport where no energy is required; substances move across membrane from high concentration to low concentration
passive transport
small, nonpolar (hydrophobic) molecules can move easily through the cell membrane from high to low concentration because membrane is mostly made of lipids (nonpolar)
diffusion
the rate of diffusion increases with:
increased concentration gradient, surface area, temperature, and permeability of membrane
movement of water across a membrane from high water concentration to low water concentration (water moves from low solute concentration to high solute concentration)
osmosis
some larger, polar (hydrophilic) substances need a protein carrier or protein channel in membrane that allow the substance to p ass directly through or change conformation when substance binds to release substance on other side (move from high to low with no energy expended)
facilitated diffusion
what are integral proteins?
proteins that allow a substance to pass directly through (channel) or change conformation when substance binds to release substance on other side (carrier), during facilitated diffusion
type of transport where energy is required; substances pumped across membrane from low concentration to high concentration (against concentration gradient)
active transport
solvent + solute = ???
solution
in osmosis, substance that is doin the dissolving (in this case water)
solvent
in osmosis, substance that is being dissolved
solute
passive movement of water across a membrane
osmosis
t or f: during osmosis, water moves from where there is more water to where there is less water
true
measure of force needed to stop osmosis
osmotic pressure
the _______ the solute concentration, the _________ the osmotic pressure
higher; higher
what happens to a red blood cell placed in an isotonic solution?
isotonic solution has same solute concentration as the red blood cell; water will move in and out of cell, the size of cell will stay the same
what happen to a red blood cell placed in a hypotonic solution?
hypotonic has lower solute concentration than inside the cell; water will move from the solution into the cell, causing the cell to swell and potentially burst (hemolyse)
what happens to a red blood cell placed in a hypertonic solution?
hypertonic has higher solute concentration than inside the cell; water will move from the cell into the solution causing it to shrivel or become smaller (crenate)
in epithelial cell junctions, the type of junction that tightly locks cells together making it very difficult for diffusion to occur between cells
tight junction
in epithelial cell junctions, the type of junction where cells are held close
adherens junction
products produced within the cells, packaged in vesicle, vesicle fuses with cell membrane and contents are released outside the cell
exocytosis
substances outside the cells interact with the cell membrane, the membrane folds in, engulfing the substance, and the substance is brought into the cell in a vesicle
endocytosis
“cell drinking” - large amounts of water can be brought into the cell in this manner
pinocytosis
“cell eating” - cells engulf microorganisms and cell debris
phagocytosis
substance binds to receptors on the cell membrane and then brought into cell through endocytosis
receptor-mediated endocytosis
most abundant cation in ICF is…
K+ (potassium ion)
most abundant cation in ECF…
Na+ (sodium ion)
if Na+ and K+ are allowed to freely move across the membrane:
K+ will move out of the cell along its electrochemical gradient until it reaches equilibrium at ___ mV
-90 mV
if Na+ and K+ are allowed to freely move across the membrane:
Na+ will move into the cell along its electrochemical gradient until it reaches equilibrium at ___ mV
+66 mV
resting membrane potential ranges from ___ mV to ___ mV depending on the cell type
-85 mV to -65 mV
type of signal where ions and molecules pass between cells through channels (important in cardiac muscle)
gap junctions
type of signal where cells release molecules that diffuse and communicate with nearby cells
paracrine signaling
type of signaling where neurons release chemicals (neurotransmitters) across a junction (synapse) to communicate with another neuron, a muscle cell, or a gland
synaptic signaling
type of signaling where endocrine glands produce hormones that travel through the blood to a target cell
endocrine signaling
true or false: signal molecules must bind to specific protein receptors on or in their target cells
true
common second messengers are:
cAMP and G-proteins (alpha, beta, and gamma subunits)
