Chapter 7 Flashcards
(46 cards)
What are the components of chemical signaling pathways?
Extracellular signaling molecules, receptors, and effectors.
What are the functional categories of extracellular signaling molecules?
Neurotransmitters, hormones, and trophic factors.
What do trophic factors promote?
Growth, development, survival, and differentiation.
Where are transmembrane receptors located?
In the plasma membrane, for impermeant and some permeant molecules.
Where are intracellular receptors located?
In the cytoplasm or nucleus, for permeant molecules only.
What is an example of an intracellular signaling molecule?
Nitric oxide.
What are ionotropic receptors?
Receptors that are part of an ion channel, generating an electrical signal.
What do G proteins do?
They can activate enzymes and participate in transcriptional regulation.
What are the advantages of intracellular signaling paths?
Amplification, multiple steps/levels of control, and spatial localization.
What are the challenges of intracellular signaling?
Maintaining the signal long enough to elicit a response and controlling signaling inactivation.
What is juxtacrine signaling?
Signaling that requires cell-cell physical contact.
What is autocrine signaling?
Signaling where the molecule binds to a receptor on the releasing cell.
What is paracrine signaling?
Signaling that diffuses within the tissue of the releasing cell.
What is endocrine signaling?
Signaling where the molecule travels in the blood.
What are the types of transmembrane receptors?
Channel-linked receptors, enzyme-linked receptors, and metabotropic G-protein coupled receptors.
What activates G-protein coupled receptors?
A signaling molecule and GTP replacing GDP.
What are the types of second messengers?
Calcium ions, cyclic nucleotides (cAMP, cGMP), diacylglycerol (DAG), and inositol triphosphate (IP3).
What is the role of calcium in signaling?
It activates kinases, triggers neurotransmitter release, and binds to transcriptional activators.
How is cAMP activated?
By trimeric Gs proteins via adenylyl cyclase.
What does diacylglycerol (DAG) activate?
Protein kinase C (PKC).
What is the role of protein kinases?
They modulate the activity of enzymes, neurotransmitter receptors, ion channels, and structural proteins.
What is the function of protein phosphatases?
They dephosphorylate proteins, modulating their activity.
What is the significance of c-fos in signaling pathways?
It acts as a transcriptional activator for other genes.
What are the characteristics of mood disorders?
Prolonged mood alterations, high heritability, and shared susceptibility genes with schizophrenia.
