ECE Biology FINAL Study Guide|80
Latest Updated Questions With Answers
What are the three stages of cell signaling? - Answer1. Reception
2. Transduction
3. Response
What happens during each stage of cell signaling? (signal transduction) - Answer1.
Reception - detection of a signal molecule (ligand) coming from outside of the cell and
binding to the receptor
2. Transduction - conversion of the signal to a form that can be used for cellular
response
3. Response - the cellular response to the signal molecule
How does a G-coupled protein receptor work? (how it is activated and gets the signal
across) - Answer1. The GPCR is activated when a signal molecule attaches to its
receptor.
2. When this happens, the G-protein travels from the inactive enzyme to the receptor
and is activated when it attaches to the receptor since it catalyzes the change of GTP to
GDP.
3. The G-protein, now with GTP, travels back to the enzyme which is then activated by
the G-protein, allowing a cellular response
How does a Tyrosine Kinase Receptor work? (how it is activated and gets the signal
across) - Answer1. A signal molecule (ligand) attaches to the binding site on the
inactive monomers in the cytoplasm. When two monomers with signal molecules are
close, they will bind to form a dimer
2. The formation of a dimer activates the tyrosine kinase regions on the monomers and
phosphorylation occurs which allows the receptor tyrosine kinase (RTK) to fully activate
with the addition of phosphates
3. Inactive relay proteins are then able to bind to the activated tyrosines, creating
cellular responses and allowing the relay proteins to become active
What is the difference between receptor tyrosine kinases (RTKs) and G-protein coupled
receptors (GPCRs)? - Answer1. RTKs - use ATP as energy
GPCRs - use GTP as energy
2. RTKs - can send multiple cellular responses
GPCRs - can only send one cellular response
, How does an Ion-gated channel work? (how it is activated and gets the signal across) -
Answer1. A signal molecule attaches to the receptor of the Ion-gated channel
2. The gate of the channel opens, allowing entry of ions across the plasma membrane
which enables a cellular response
3. Once the signal molecule leaves, the gate closes and ions are unable to go through
the channel
What happens during the phosphorylation cascade? (how the signal gets across and
what happens to the protein during phosphorylation) - Answer1. A signal molecule
binds to the receptor, resulting in the activation of a relay molecule because of the
addition of a phosphoryl group.
2. The Inactive protein kinases in the cascade become active when a phosphoryl group
is added. This constant transfer of phosphoryl groups between inactive and active
kinases continues, amplifying the signal throughout the cascade
3. Eventually, the inactive protein at the end of the cascade obtains a phosphoryl group
and is activated which allows the now-activated protein to send an amplified cellular
response
What are examples of secondary messengers? - Answercyclic AMP (cAMP), calcium
ions (CA 2+), and inositol triphosphate (IP3) - they all relay a signal inside of a cell
Give an example of how a secondary messenger can create cellular responses. -
AnswerCyclic AMP (cAMP):
The activated protein from a GPCR activates the adenylyl kinase which converts ATP to
cAMP (second messenger). The cAMP activates the protein kinase A which creates
multiple cellular responses
What does apoptosis mean? What can apoptosis do? - Answercell suicide; protect
neighboring cells from damage and helps animal development and maintenance
What are the structural differences between bacteria and viruses - AnswerBacteria:
Prokaryotic cell
Most are free-living (some parasitic)
Live inside or outside the body
Relatively large size
Antibiotics used to treat bacteria
Viruses:
Not a living cell (genes packaged in protein shell)
Intracellular parasite
Need a host to survive - mutate easily and reproduce quickly
Latest Updated Questions With Answers
What are the three stages of cell signaling? - Answer1. Reception
2. Transduction
3. Response
What happens during each stage of cell signaling? (signal transduction) - Answer1.
Reception - detection of a signal molecule (ligand) coming from outside of the cell and
binding to the receptor
2. Transduction - conversion of the signal to a form that can be used for cellular
response
3. Response - the cellular response to the signal molecule
How does a G-coupled protein receptor work? (how it is activated and gets the signal
across) - Answer1. The GPCR is activated when a signal molecule attaches to its
receptor.
2. When this happens, the G-protein travels from the inactive enzyme to the receptor
and is activated when it attaches to the receptor since it catalyzes the change of GTP to
GDP.
3. The G-protein, now with GTP, travels back to the enzyme which is then activated by
the G-protein, allowing a cellular response
How does a Tyrosine Kinase Receptor work? (how it is activated and gets the signal
across) - Answer1. A signal molecule (ligand) attaches to the binding site on the
inactive monomers in the cytoplasm. When two monomers with signal molecules are
close, they will bind to form a dimer
2. The formation of a dimer activates the tyrosine kinase regions on the monomers and
phosphorylation occurs which allows the receptor tyrosine kinase (RTK) to fully activate
with the addition of phosphates
3. Inactive relay proteins are then able to bind to the activated tyrosines, creating
cellular responses and allowing the relay proteins to become active
What is the difference between receptor tyrosine kinases (RTKs) and G-protein coupled
receptors (GPCRs)? - Answer1. RTKs - use ATP as energy
GPCRs - use GTP as energy
2. RTKs - can send multiple cellular responses
GPCRs - can only send one cellular response
, How does an Ion-gated channel work? (how it is activated and gets the signal across) -
Answer1. A signal molecule attaches to the receptor of the Ion-gated channel
2. The gate of the channel opens, allowing entry of ions across the plasma membrane
which enables a cellular response
3. Once the signal molecule leaves, the gate closes and ions are unable to go through
the channel
What happens during the phosphorylation cascade? (how the signal gets across and
what happens to the protein during phosphorylation) - Answer1. A signal molecule
binds to the receptor, resulting in the activation of a relay molecule because of the
addition of a phosphoryl group.
2. The Inactive protein kinases in the cascade become active when a phosphoryl group
is added. This constant transfer of phosphoryl groups between inactive and active
kinases continues, amplifying the signal throughout the cascade
3. Eventually, the inactive protein at the end of the cascade obtains a phosphoryl group
and is activated which allows the now-activated protein to send an amplified cellular
response
What are examples of secondary messengers? - Answercyclic AMP (cAMP), calcium
ions (CA 2+), and inositol triphosphate (IP3) - they all relay a signal inside of a cell
Give an example of how a secondary messenger can create cellular responses. -
AnswerCyclic AMP (cAMP):
The activated protein from a GPCR activates the adenylyl kinase which converts ATP to
cAMP (second messenger). The cAMP activates the protein kinase A which creates
multiple cellular responses
What does apoptosis mean? What can apoptosis do? - Answercell suicide; protect
neighboring cells from damage and helps animal development and maintenance
What are the structural differences between bacteria and viruses - AnswerBacteria:
Prokaryotic cell
Most are free-living (some parasitic)
Live inside or outside the body
Relatively large size
Antibiotics used to treat bacteria
Viruses:
Not a living cell (genes packaged in protein shell)
Intracellular parasite
Need a host to survive - mutate easily and reproduce quickly
