BMB 252 Exam 1 – Study Guide, Practice Questions & Revision Notes
what binds to an extracellular signal - correct answer ✔✔receptor
some signal transduction proteins are similar/homologous in yeast and humans - correct answer
✔✔true
what are signaling molecule examples - correct answer ✔✔CO, nucleotide, steriod,
neurotransmitter
some signaling molecules can travel through the cellular membrane and bind to their targets
inside the cell - correct answer ✔✔true
what signaling types can be used to guide cell movement - correct answer ✔✔paracrine and
contact dependent
lymphocytes have receptors for their own signals that result in their self activation as well; this
type of signaling is called - correct answer ✔✔autocrine
neurotransmitters have higher affinity to their receptors than hormones - correct answer
✔✔false
if a cell recieves no signal, it will die - correct answer ✔✔true
which signal is transduced faster - correct answer ✔✔the one that changes the protein
modification state
acetylcholine always causes muscles to contract - correct answer ✔✔false
,acetylcholines binds to only one kind of receptor - correct answer ✔✔false
ion pumps pump signals back into what to clear the synapse - correct answer ✔✔the
presynaptic cell
what is irreversible: receptor sequestration or down-regulation? - correct answer
✔✔sequestration
which feedback loop can result in oscillation? - correct answer ✔✔negative
which of the following can diffuse freely through the plasma membrane and does not require
channels? CO2, H20, K+ - correct answer ✔✔CO2
autocrine signaling is analagous to - correct answer ✔✔talking to yourself
which of the receptors have the lowest affinity to their signaling molecules - correct answer
✔✔acetylcholine receptors in the synapse
maintaining constant protein expression throughout the lifetime is based on what - correct
answer ✔✔positive feedback loops
ion channel linked receptors are mostly located on - correct answer ✔✔at synapses on
postsynaptic neurons
phosphorylation of an enzyme always turns it on - correct answer ✔✔false
GPCR is a GEF for G protein - correct answer ✔✔true
, what happens to a cell in the absence of a signal - correct answer ✔✔apoptosis- programmed
cell death
What keeps the signal localized in paracrine signaling? - correct answer ✔✔they can quickly be
absorbed by other cells, get degraded by extracellular enzymes, and get trapped in extracellular
matrix
what kinds of molecules can act as signals - correct answer ✔✔proteins, small peptides, amino
acids, nucleotides, steroids, retinoids, fatty acid derivatives, dissolved gases (CO, NO)
difference between signaling molecules that bind to intracellular and cell-surface receptors? -
correct answer ✔✔cell surface signals= hydrophillic; intracellular= hydrophobic (must pass
through lipid bilayer)
four forms of intercellular signaling - correct answer ✔✔contact-dependent, paracrine,
endocrine, synaptic
synaptic vs. endocrine signaling - correct answer ✔✔endocrine= slow signal delivery/diffusion,
low concentration of signal (hormones are in low concentration in the blood), high affinity for
receptors; synaptic= fast signal delivery/diffusion, high concentration of signal (lots of
neurotransmitters at synapse), low affinity for receptors (neurotransmitters must dissociate fast
to clear synapse)
what determines the speed of intracellular transmission in response to a signal? - correct
answer ✔✔phosphorylations and altered protein function (fast) and altered protein synthesis
(slow)
what kinds of responses can acetylcholine illicit? does it always bind to the same receptor? -
correct answer ✔✔muscle cells= contract in response to acetylcholine; heart muscles cells=
relax; NO, different receptors for the same signal create a different response
what binds to an extracellular signal - correct answer ✔✔receptor
some signal transduction proteins are similar/homologous in yeast and humans - correct answer
✔✔true
what are signaling molecule examples - correct answer ✔✔CO, nucleotide, steriod,
neurotransmitter
some signaling molecules can travel through the cellular membrane and bind to their targets
inside the cell - correct answer ✔✔true
what signaling types can be used to guide cell movement - correct answer ✔✔paracrine and
contact dependent
lymphocytes have receptors for their own signals that result in their self activation as well; this
type of signaling is called - correct answer ✔✔autocrine
neurotransmitters have higher affinity to their receptors than hormones - correct answer
✔✔false
if a cell recieves no signal, it will die - correct answer ✔✔true
which signal is transduced faster - correct answer ✔✔the one that changes the protein
modification state
acetylcholine always causes muscles to contract - correct answer ✔✔false
,acetylcholines binds to only one kind of receptor - correct answer ✔✔false
ion pumps pump signals back into what to clear the synapse - correct answer ✔✔the
presynaptic cell
what is irreversible: receptor sequestration or down-regulation? - correct answer
✔✔sequestration
which feedback loop can result in oscillation? - correct answer ✔✔negative
which of the following can diffuse freely through the plasma membrane and does not require
channels? CO2, H20, K+ - correct answer ✔✔CO2
autocrine signaling is analagous to - correct answer ✔✔talking to yourself
which of the receptors have the lowest affinity to their signaling molecules - correct answer
✔✔acetylcholine receptors in the synapse
maintaining constant protein expression throughout the lifetime is based on what - correct
answer ✔✔positive feedback loops
ion channel linked receptors are mostly located on - correct answer ✔✔at synapses on
postsynaptic neurons
phosphorylation of an enzyme always turns it on - correct answer ✔✔false
GPCR is a GEF for G protein - correct answer ✔✔true
, what happens to a cell in the absence of a signal - correct answer ✔✔apoptosis- programmed
cell death
What keeps the signal localized in paracrine signaling? - correct answer ✔✔they can quickly be
absorbed by other cells, get degraded by extracellular enzymes, and get trapped in extracellular
matrix
what kinds of molecules can act as signals - correct answer ✔✔proteins, small peptides, amino
acids, nucleotides, steroids, retinoids, fatty acid derivatives, dissolved gases (CO, NO)
difference between signaling molecules that bind to intracellular and cell-surface receptors? -
correct answer ✔✔cell surface signals= hydrophillic; intracellular= hydrophobic (must pass
through lipid bilayer)
four forms of intercellular signaling - correct answer ✔✔contact-dependent, paracrine,
endocrine, synaptic
synaptic vs. endocrine signaling - correct answer ✔✔endocrine= slow signal delivery/diffusion,
low concentration of signal (hormones are in low concentration in the blood), high affinity for
receptors; synaptic= fast signal delivery/diffusion, high concentration of signal (lots of
neurotransmitters at synapse), low affinity for receptors (neurotransmitters must dissociate fast
to clear synapse)
what determines the speed of intracellular transmission in response to a signal? - correct
answer ✔✔phosphorylations and altered protein function (fast) and altered protein synthesis
(slow)
what kinds of responses can acetylcholine illicit? does it always bind to the same receptor? -
correct answer ✔✔muscle cells= contract in response to acetylcholine; heart muscles cells=
relax; NO, different receptors for the same signal create a different response
