Cell Signaling Flashcards
Direct Contact Signaling
regulatory signals that originate from conditions within a cell
Synaptic Signaling
Communication signals occurring between neighboring cells
Endocrine Signaling
response to extracellular regulatory signals that are generated to coordinate metabolic activities and other activities for the survival of the cell
G-Protein Coupled Receptors
extracellular ligand binding domain
7 transmembrane spanning domains
cytosolic G protein activation domain
Adenylyl Cyclase
integral membrane protein uses energy (ATP) to generate cAMP
Ion Channels
Regulate flow of specific ions across membranes
Dephosphorylation of Proteins
protein phosphatases hydrolytically cleave phosphate esters- remove/dephosphorylate effector proteins phosphorylated by protein kinases
Toxin Entry into Cells
Secretion of cholera toxin to gut lumen
endosomal uptake of catalytic subunit A (component of cholera toxin)
Exit from endosome into cytosol and cleavage to catalytic peptide A1
Effect of cholera toxin
Secretion of Cl and bicarbonate results in Na and water secretion
reabsorptive function of colon overwhelmed
dehydratio and electrolyte imbalance
Insulin
water soluble protein hormone
produced in B cells of islets of Langerhans (pancreas)
stored in secretory granules
promotes production of glycogen, triacylglycerols, protein
Insulin and Glucose
Increase of glucose in blood= increase in insulin release
decrease glucagon
Insulin and Amino Acids
increase in AA causes increase in insulin secretion
glucagon release increases- increases glucose uptake
Insulin and Gastrointestinal Hormones
peptide hormones released from SI as insulin is released in response to food intake
Factors that negatively affect insulin secretion
scarcity of dietary fuels- glucose and AA
increase of epinephrine in blood
Epinephrine release
secreted in adrenal medulla in response to stress, trauma, exercise
