Questions With Verified Expert Solutions | Latest
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Osmosis - ANSWER Diffusion of water through a selectively
permeable membrane; from a region of higher water
concentration to a region of lower water concentration; directly r/t
hydrostatic pressure and solute concentration; PULL
active transport - ANSWER the movement of materials through a
cell membrane using energy
mediated transport - ANSWER simultaneous movement of a
single solute molecule in one direction (uniport); of two different
solute molecules in one direction (symport); of two different solute
molecules in opposite directions (antiport)
passive mediated transport - ANSWER "facilitated diffusion;"
moving molecules through membranes WITHOUT expending
energy; moving DOWN a concentration gradient
active mediated transport - ANSWER "active transport;"
Requires the expenditure of metabolic energy (ATP); moving UP
or AGAINST a concentration gradient; the major cellular energy
currency
Endocytosis - ANSWER a section of the plasma membrane
enfolds substances from outside the cell, invaginates (folds
inward), and separates from the plasma membrane, forming a
vesicle that moves into the cell; lyzosomal enzymes destroy
molecules in the vesicles
, Pinocytosis - ANSWER "Cell drinking;" A type of endocytosis
that involves the ingestion of fluids and solute molecules through
formation of small vesicles
Phagocytosis - ANSWER "Cell eating;" a type of endocytosis
that involves the ingestion of large particles, such as bacteria,
through formation of large vesicles (vacuoles)
Exocytosis - ANSWER secretion of macromolecules; helps
replace portions of the plasma membrane; also releases
molecules synthesized by the cells into the extracellular matrix
3 ways cells communicate - ANSWER endocrine signaling,
paracrine signaling, synaptic signaling
endocrine signaling - ANSWER remote signaling by secretion
molecules (hormones) in the blood to remote cells
paracrine signaling - ANSWER secretion of local chemical
mediators that are quickly taken up and immobilized; contact
signaling by plasma membrane bound molecules
synaptic signaling - ANSWER secretion of neurotransmitters @
specialized junctions called chemical synapse; contact signaling
via gap junctions
Glycolysis - ANSWER the 2nd phase of cellular energy
production following digestion; in this phase, a glucose molecule
is split forming 2 molecules of ATP through the process of
oxidation; in anaerobic conditions, this process provides energy
for the cell