BIOS 390 Exam; Questions and Answers 100% Solved
Describe the step in PIP2 system pathway. Correct Ans-A nt binds to a R, the G protein q
subunit activates phospholipase C to act on PIP2 so it splits into IP3 and DAG, both act as 2nd
messengers independently. DAG + Ca activates PKC to phosphorylate targets, IP3 binds to Rs
on the ER to facilitate release of Ca.
How are protein tyrosine kinases similar and different from the other types of protein kinases
that we discussed? Functionally and structurally? Correct Ans-Tyrosine kinases are enzyme
linked, once a ligand binds to an R 2 subunits come together (dimerization) and
autophosphorylation occurs. The R itself has enzymatic activity. R tyr kinase -> ras -> MAPK ->
phosphorylate CREB w/in the nucleus along with other protein kinases to alter RNA
transcription.
What are and describe in detail the three types of SHORT-TERM synaptic plasticity that result
in an increase in synaptic strength? How do their time courses differ? Are these changes pre-
synaptic or postsynaptic? Correct Ans-Paired pulse facilitation - msecs. When 2 APs are
closely spaced.
Augmentation - secs. Occurs after repeated stim, induce a longer response.
PTP - Post tetanic potentiation, mins. High freq stim, produces a longer response than
augmentation
, BIOS 390 Exam; Questions and Answers 100% Solved
Ca build up in presyn terminal. Enhance the ability of Ca to trigger fusion of vesicles to pm to
release contents.
What is the synaptic basis (cellular mechanisms) for short-term sensitization in Aplysia?
Correct Ans-The modulatory neuron, stimulated from its tail, releases 5HT onto the
sensory neuron of the siphon. The 5HT R is activated, G alpha s protein stim AC -> cAMP ->
PKA's catalytic subunits phos targets. K channels are blocked to lengthen AP duration, more
Ca channels open to allow Ca in -> more vesicles release their contents (glutamate) to Rs on
motor neuron -> Ach onto gill.
What additional changes underlie long-term sensitization? Correct Ans-During long term
sensitization, repeated stim has PKA activate CREB w/in the nucleus -> makes ubiquitin
hydrolase that inhibits the regulatory subunits from acting, PKA's catalytic subunits are the
only ones active & don't need 5HT. Constant Ach acting on the gill.
How is long term potentiation induced in the hippocampus? Correct Ans-High-frequency
stimulation is needed to depolarize the cell/neuron and unblock the NMDA receptor pore's
Mg ion
Describe the step in PIP2 system pathway. Correct Ans-A nt binds to a R, the G protein q
subunit activates phospholipase C to act on PIP2 so it splits into IP3 and DAG, both act as 2nd
messengers independently. DAG + Ca activates PKC to phosphorylate targets, IP3 binds to Rs
on the ER to facilitate release of Ca.
How are protein tyrosine kinases similar and different from the other types of protein kinases
that we discussed? Functionally and structurally? Correct Ans-Tyrosine kinases are enzyme
linked, once a ligand binds to an R 2 subunits come together (dimerization) and
autophosphorylation occurs. The R itself has enzymatic activity. R tyr kinase -> ras -> MAPK ->
phosphorylate CREB w/in the nucleus along with other protein kinases to alter RNA
transcription.
What are and describe in detail the three types of SHORT-TERM synaptic plasticity that result
in an increase in synaptic strength? How do their time courses differ? Are these changes pre-
synaptic or postsynaptic? Correct Ans-Paired pulse facilitation - msecs. When 2 APs are
closely spaced.
Augmentation - secs. Occurs after repeated stim, induce a longer response.
PTP - Post tetanic potentiation, mins. High freq stim, produces a longer response than
augmentation
, BIOS 390 Exam; Questions and Answers 100% Solved
Ca build up in presyn terminal. Enhance the ability of Ca to trigger fusion of vesicles to pm to
release contents.
What is the synaptic basis (cellular mechanisms) for short-term sensitization in Aplysia?
Correct Ans-The modulatory neuron, stimulated from its tail, releases 5HT onto the
sensory neuron of the siphon. The 5HT R is activated, G alpha s protein stim AC -> cAMP ->
PKA's catalytic subunits phos targets. K channels are blocked to lengthen AP duration, more
Ca channels open to allow Ca in -> more vesicles release their contents (glutamate) to Rs on
motor neuron -> Ach onto gill.
What additional changes underlie long-term sensitization? Correct Ans-During long term
sensitization, repeated stim has PKA activate CREB w/in the nucleus -> makes ubiquitin
hydrolase that inhibits the regulatory subunits from acting, PKA's catalytic subunits are the
only ones active & don't need 5HT. Constant Ach acting on the gill.
How is long term potentiation induced in the hippocampus? Correct Ans-High-frequency
stimulation is needed to depolarize the cell/neuron and unblock the NMDA receptor pore's
Mg ion
