PSL300 Term Test 1 Questions and Correct
Answers
simple diffusion
small, lipid-soluble molecs and gases (e.g. O2, CO2, ethanol, urea, etc) pass either directly
thru phospholipid bilayer or thru pores
passive
no E input required from breakdown of ATP
facilitated diffusion
process of diffusion where molecs diffuse across membrane w/ assistance of carrier protein
(these proteins are not continuous holes; one end is always closed, unlike channels)
active transport
mechanism to move selected molecs across cell membranes, against their [ ] gradient
secondary active transport
When a substance is carried up its [ ] gradient w/out ATP catabolism
ligand gated channel
channel that opens w/ binding of chemical agent
voltage gated channel
channel that opens in response to change of voltage across the membrane
endocytosis
inward 'pinching' of membrane to create a vesicle; usually receptor-mediated to capture
proteins, from outside to inside
, exocytosis
partial or complete fusion of vesicles w/ cell membrane for bulk trans-membrane transport of
specific molecs, from inside to outside
kiss and run
the secretory vesicles dock and fuse w/ plasma membrane at specific locations called 'fusion
pores'; rapid mechanism
full exocytosis
involves complete fusion of vesicle w/ membrane, leading to total release of vesicle contents
at once
membrane potential
potential diff across a cell
Na+/K+ Pump
enzyme that moves Na+ out of cell and K+ into cell by breaking down ATP
resting membrane potential
MP of cell at rest
action potential
an impulse, a v short-lived change in MP used as a signal/message
threshold
Min depolarization necessary to induce regenerative mechanism for opening of Na+ channels
subthreshold stimulus
Answers
simple diffusion
small, lipid-soluble molecs and gases (e.g. O2, CO2, ethanol, urea, etc) pass either directly
thru phospholipid bilayer or thru pores
passive
no E input required from breakdown of ATP
facilitated diffusion
process of diffusion where molecs diffuse across membrane w/ assistance of carrier protein
(these proteins are not continuous holes; one end is always closed, unlike channels)
active transport
mechanism to move selected molecs across cell membranes, against their [ ] gradient
secondary active transport
When a substance is carried up its [ ] gradient w/out ATP catabolism
ligand gated channel
channel that opens w/ binding of chemical agent
voltage gated channel
channel that opens in response to change of voltage across the membrane
endocytosis
inward 'pinching' of membrane to create a vesicle; usually receptor-mediated to capture
proteins, from outside to inside
, exocytosis
partial or complete fusion of vesicles w/ cell membrane for bulk trans-membrane transport of
specific molecs, from inside to outside
kiss and run
the secretory vesicles dock and fuse w/ plasma membrane at specific locations called 'fusion
pores'; rapid mechanism
full exocytosis
involves complete fusion of vesicle w/ membrane, leading to total release of vesicle contents
at once
membrane potential
potential diff across a cell
Na+/K+ Pump
enzyme that moves Na+ out of cell and K+ into cell by breaking down ATP
resting membrane potential
MP of cell at rest
action potential
an impulse, a v short-lived change in MP used as a signal/message
threshold
Min depolarization necessary to induce regenerative mechanism for opening of Na+ channels
subthreshold stimulus
