BIOL 1201 FINAL EXAM QUESTIONS
AND ANSWERS 100% CORRECT
local signaling - ANSWER-animal cells may communicate by direct contact, or cell-cell
recognition (paracrine and synaptic signaling)
cell junctions - ANSWER-Animal and plant cells; directly connect the cytoplasm of
adjacent cells
paracrine signaling - ANSWER-the target cells lie near the secreting cells
synaptic signaling - ANSWER-a nerve cell releases neurotransmitter molecules into a
synapse, stimulating the target cell
endocrine (hormonal) signaling - ANSWER-Specialized endocrine cells secrete
hormones into body fluids, often blood. Hormones reach virtually all body cells, but are
bound only by some cells.
cell-cell recognition - ANSWER-two cells in an animal may communicate by interaction
between molecules protruding from their surfaces
three stages of cell signaling - ANSWER-reception, transduction, response
reception - ANSWER-The target cell's detection of a signal molecule coming from
outside the cell.
transduction - ANSWER-the binding of the signaling molecule alters the receptor and
initiates a signal transduction pathway; occurs in a series of steps
response - ANSWER-the transduced signal triggers a specific response in the target
cell
signal transduction pathway - ANSWER-A series of steps linking a mechanical or
chemical stimulus to a specific cellular response
pathways leading to the release of calcium involve ____ and ____ as additional second
messengers - ANSWER-inositol triphosphate (IP3) and diacylglycerol (DAG)
output response - ANSWER-cell's response to extracellular signal
four aspects of signal regulation - ANSWER-amplification, specificity, efficiency,
termination
, signal amplification - ANSWER-Enzyme cascades amp the cell's response to a signal.
At each step in the cascade, the number of activated products is much greater than the
prev step
ligand - ANSWER-Signal molecule that binds to the receptor
three main types of membrane receptors - ANSWER--G protein-coupled receptors
-Receptor tyrosine kinases
-Ion channel receptors
G protein-coupled receptors (GPCRs) - ANSWER-cell-surface transmembrane
receptors that work with the help of a G protein
Receptor Tyrosine Kinases (RTKs) - ANSWER-membrane receptors that transfer
phosphate groups from ATP to another protein
ligand-gated ion - ANSWER-acts as a gate that opens and closes when the receptor
changes shape
intracellular receptors - ANSWER-receptors located inside the cell rather than on its cell
membrane
phosphorylation - ANSWER-the addition of a phosphate group to a molecule
dephosphorylation - ANSWER-removal of a phosphate group from a molecule
second messengers - ANSWER-Small, non-protein water soluble molecules or ions that
send messages throughout the cells by diffusion.
common second messengers - ANSWER-cyclic AMP and calcium ions
cyclic AMP (cAMP) - ANSWER-A compound formed from ATP that acts as a second
messenger; one of the most commonly used
adenylyl cyclase - ANSWER-an enzyme in the plasma membrane, converts ATP to
cAMP in response to an extracellular signal
phosphorylation cascade - ANSWER-a sequence of events where one enzyme
phosphorylates another, causing a chain reaction leading to the phosphorylation of
thousands of proteins
protein phosphates - ANSWER-Enzymes that can rapidly remove phosphate groups
from proteins.
calcium ions (Ca2+) - ANSWER-more widely used as a second messenger than cAMP;
concentration in the cytosol is much lower than the concentration outside the cell
AND ANSWERS 100% CORRECT
local signaling - ANSWER-animal cells may communicate by direct contact, or cell-cell
recognition (paracrine and synaptic signaling)
cell junctions - ANSWER-Animal and plant cells; directly connect the cytoplasm of
adjacent cells
paracrine signaling - ANSWER-the target cells lie near the secreting cells
synaptic signaling - ANSWER-a nerve cell releases neurotransmitter molecules into a
synapse, stimulating the target cell
endocrine (hormonal) signaling - ANSWER-Specialized endocrine cells secrete
hormones into body fluids, often blood. Hormones reach virtually all body cells, but are
bound only by some cells.
cell-cell recognition - ANSWER-two cells in an animal may communicate by interaction
between molecules protruding from their surfaces
three stages of cell signaling - ANSWER-reception, transduction, response
reception - ANSWER-The target cell's detection of a signal molecule coming from
outside the cell.
transduction - ANSWER-the binding of the signaling molecule alters the receptor and
initiates a signal transduction pathway; occurs in a series of steps
response - ANSWER-the transduced signal triggers a specific response in the target
cell
signal transduction pathway - ANSWER-A series of steps linking a mechanical or
chemical stimulus to a specific cellular response
pathways leading to the release of calcium involve ____ and ____ as additional second
messengers - ANSWER-inositol triphosphate (IP3) and diacylglycerol (DAG)
output response - ANSWER-cell's response to extracellular signal
four aspects of signal regulation - ANSWER-amplification, specificity, efficiency,
termination
, signal amplification - ANSWER-Enzyme cascades amp the cell's response to a signal.
At each step in the cascade, the number of activated products is much greater than the
prev step
ligand - ANSWER-Signal molecule that binds to the receptor
three main types of membrane receptors - ANSWER--G protein-coupled receptors
-Receptor tyrosine kinases
-Ion channel receptors
G protein-coupled receptors (GPCRs) - ANSWER-cell-surface transmembrane
receptors that work with the help of a G protein
Receptor Tyrosine Kinases (RTKs) - ANSWER-membrane receptors that transfer
phosphate groups from ATP to another protein
ligand-gated ion - ANSWER-acts as a gate that opens and closes when the receptor
changes shape
intracellular receptors - ANSWER-receptors located inside the cell rather than on its cell
membrane
phosphorylation - ANSWER-the addition of a phosphate group to a molecule
dephosphorylation - ANSWER-removal of a phosphate group from a molecule
second messengers - ANSWER-Small, non-protein water soluble molecules or ions that
send messages throughout the cells by diffusion.
common second messengers - ANSWER-cyclic AMP and calcium ions
cyclic AMP (cAMP) - ANSWER-A compound formed from ATP that acts as a second
messenger; one of the most commonly used
adenylyl cyclase - ANSWER-an enzyme in the plasma membrane, converts ATP to
cAMP in response to an extracellular signal
phosphorylation cascade - ANSWER-a sequence of events where one enzyme
phosphorylates another, causing a chain reaction leading to the phosphorylation of
thousands of proteins
protein phosphates - ANSWER-Enzymes that can rapidly remove phosphate groups
from proteins.
calcium ions (Ca2+) - ANSWER-more widely used as a second messenger than cAMP;
concentration in the cytosol is much lower than the concentration outside the cell
