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Cell Bio Cell Signaling

Questions from Dr Groppe's lecture on cell signaling
STUDY
PLAY
________________ receptors convert chemical into electrical signals.
Ion channel-linked
What is the conversion of one type of signal into another?
Signal Transduction
What are four types of cell signaling?
Endocrine, Paracrine, Neuronal, and Contact-dependent
__________________ signaling controls nerve-cell production.
Contact-dependent
True or false: The same signal molecule can induce different responses in different target cells.
True
Extracellular signals alter the activity of diverse cell _________ to alter cellular behavior.
proteins
Extracellular signal molecules can bind to ______________ receptors or _____________ receptors and enzymes.
extracellular; intracellular
Nitric oxide (NO) triggers smooth muscle _____________ in a blood-vessel wall.
relaxation
Steroid hormones bind intracellular receptors that act as _________________________ proteins.
gene regulatory
True or false: Gases such as NO are the only signal molecules that can cross the plasma membrane.
False.
The steroid hormone __________ acts by activating a gene regulatory protein.
Cortisol
What are the three basic classes of cell surface receptors?
G-protein-linked, Ion-channel-linked, and Enzyme-linked
Many intracellular signaling proteins act as ___________________.
molecular switches
True or false: All G-protein-linked receptors possess a similar structure.
True
When activated, G-proteins....?
dissociate into two signaling proteins
The G protein alpha-subunit switches itself off by _______________________.
hydrolyzing bound GTP
G proteins couple receptor activation to opening of _______________ K+ channels.
cardiomyocyte
What catalyzes the synthesis of intracellular second-messengers?
Enzymes activated by G-proteins
Cyclic AMP is synthesized by ____________, and degraded by __________________
adenyl cyclase; cyclic AMP phosphodiesterase
Cyclic AMP concentration rises rapidly in response to which extracellular signal?
neurotransmitter serotonin
Receptor tyrosine kinases activate the GTP-binding protein _____.
Ras
_______________ networks integrate information to control complex cell behaviors.
Protein kinase
Activation of a _______________________ directs assembly of an intracellular complex.
receptor tyrosine kinase
True or false: The Ras protein is monomeric and a membrane-linked GTPase.
True
__________ percent of human cancers come from activating mutations in ras genes.
Thirty
________________ activates a MAP-kinase phosphorylation cascade
Ras GTPase
What receptors are associated with cytoplasmic tyrosine kinases?
Cytokine receptors
TGF-beta/BMP receptors activate ___________________ directly at the plasma membrane.
gene regulatory proteins