Cell signaling Flashcards
Example of gap junction signaling
Glucagon receptors on liver cells are not evenly distributed
Connexins disperse glucagon molecules to coordinate cAMP signaling
How many connexin molecules make a half pore?
6
Example of contact-dependent signaling
Glycoproteins of leukocyte adhere to receptors on endothelial cells to guide them to injury site
What transmembrane protein is responsible for leukocytes binding to endothelial cells?
Integrins
Example of signaling with secreted molecules
ACh to adrenergic receptors
What is endocrine signaling?
Molecules transported by the bloodstream
What is paracrine signaling?
Molecules diffuse to nearby cells
What is autocrine signaling?
Molecules diffuse to same type of cell or to upregulate producing cell
Name a molecule that uses endocrine signaling
Anti-diuretic hormone
What is the function of ADH?
Low blood pressure (vasoconstriction)
High blood osmolarity (water retention)
What are the receptors of ADH?
Vasopressin 1 - smooth muscle cells, arteries
Vasopressin 2 - Kidney collecting ducts
Name a molecule that uses Paracrine signaling
Nitric oxide
What is the function of nitric oxide?
Vasodilation during inflammation
What enzyme is activated after NO binds to histamine receptors?
Guanylyl cyclase
Name a molecule that uses neuronal signaling
Acetylcholine
What is the function of acetylcholine?
Voluntary muscle contraction
What is the receptor for acetycholine?
Nicotinic acetylcholine receptor
What is the difference between endocrine and synaptic receptors?
Endocrine receptors need low concentration of molecule to reach many cells
Synaptic receptors need high concentration of molecules to reach specific cells.
What is the difference between water-soluble and lipid-soluble receptors?
Extracellular vs intracellular receptors
Name a water-soluble signaling molecule
Epinephrine
Name a fat-soluble receptor signaling molecule
aldosterone
What are the 3 types of target molecules?
Cell surface receptors
Intracellular Receptors
Intracellular enzymes
Name a signaling molecule that uses cell-surface receptors
ADH
Name a signaling molecule that uses an intracellular receptor
Aldosterone
What is the function of aldosterone?
Modulate high K+ in serum by inducing kidney to excrete K+ and retain H2O and Na+
Name a signaling molecule that uses intracellular enzymes
Nitric oxide
