Cell Signaling I Flashcards
T or F: most cell signals can cross the cell membrane.
False - only a few can do this. Most act through specific cell receptors.
Name a neurotransmitter signal.
Acetyl choline
Name gases that acts as signals.
NO, CO, CO2, O2
Name lipids that can act as signals.
Prostaglandins, leukotrienes
Name nucleotides that acts as signals.
ATP, GTP
Name AAs that acts as signals.
Glutamate, epinephrine, histamine, serotonin
Name peptides that act as signals.
Ang II, vasopressin, ANP/ANF (diuretic), endorphins
Name proteins that act as signals.
Insulin, glucagon, GH
Name steroids that acts as signals.
Cortisol, thyroxin, testosterone, estrogen
Give an example of a type of cell that uses gap junctions for signaling.
Cardiac muscle cells in ventricle - allow ventricle to beat as a single unit
What is autocrine signaling?
Single cell makes both the signal and receptor
What is paracrine signaling?
Once cell makes a signal that is received by receptor on a neighboring cell
What are the hydrophobic signals that CAN cross the cell membrane and bind internal cell receptors?
(GRATSV)
Gases (CO, NO, CO2, O2), retinoic acid, thyroxin, steroids, vitamins A and D
What hormone promotes growth in cells and indicates “good times”?
Insulin
What hormone is a stress signal?
Cortisol
What hormone is a hunger signal?
Glucagon
What hormone is an emergency signal?
Epinephrine
What hormone is an antidiuretic? What does it do?
ADH/vasopressin (peptide hormone) - preserves fluid and increases thirst
What hormone promotes diuresis?
ANF/ANP (atrial natriuretic factor) - peptide hormone
What signal would become elevated in a patient with edema?
ANF/ANP
What are the four different ways cells can signal?
1) Ion channel-linked - fastest
2) G protein-linked - faster
3) Enzyme- linked - slower
4) Alter gene expression - slowest (steroids)
What is the effect on the cell membrane potential when opening calcium channels?
Depolarization
What is the effect on the cell membrane potential when opening chloride channels?
Hyperpolarization
Most channels are in a closed state. What must you do to open a channel?
Voltage-gated, stress-activated, or bind TWO ligand molecules (ligand-gated)
How do GABAs and diazepams like Valium work? What do they do?
Open chloride channels so cell hyperpolarizes - treats anxiety
How does lidocaine work and what does it do?
Blocks Na+ channels - local anesthetic
How do sulfonylureas work and what do they do?
Block K+ channels so more insulin is released - treats diabetes
How does Nifedipine work?
Blocks Ca2+ channels - dilates blood vessels - treats hypertension
What are the two mechanisms you can use to increase chloride flow?
Increase duration of opening - barbiturates
Increase frequency of opening - benzodiazepines
