Hormonal signalling Flashcards
What must the cell have for the hormone to elicit a specific response to the cell
Possess specific receptor proteins
Transduction
Receptors by initiating signalling events or cellular mechanism that result in target cells response
What ways can a hormone signal respond
Stimulation of protein synthesis
Activation or deactivation of enzymes
Alteration in the permeability of the cell membrane
Altered rates of mitosis and cell growth
Stimulation of the secretion of products
What is signalling amplification
Any molecules that catalyse a reaction can do so multiple times producing more than one product.
What does insulin affect
Glycolysis
Glucose uptake
Gluconeogenesis
Cell growth
What are the 2 main classes of hormone receptors
Cell surface- transmembrane receptors
Intracellular receptors
Transmembrane receptor function
Hormones that cannot cross the plasma membrane will use cell surface receptors
Transmembrane receptors type
Extracellular
Intracellular
Transmembrane domains
Receptors transfer signal from outside of cell to the inside then what
Triggering a single transduction cascade
What enzyme carries out phosphorylation
Kinase enzymes
What reverses the phosphorylation reaction
Phosphatases
What is phosphorylation
The transfer of a phosphate group
Tyrosine kinase function
Phosphorylates tyrosine amino acid residues
Enzyme linked cell surface receptors pathways
Insulin binds insulin receptor
Tyrosine kinase on cytoplasmic side of receptor is activated
Kinase causes phosphorylation of intracellular proteins triggers cascade reactions
What is the most common signal transduction pathway
Signalling through G protein linked receptors
G protein linked receptor signalling route 1
Hormone
Receptor
Adenylate cyclase
Cyclic AMP
Protein kinase A
Glucose metabolism
G protein linked receptor signalling route 2
Hormone
Receptor
Phospholipase C
IP3
Calcium
Glucose metabolism
Secondary messengers
Cyclic AMP- cAMP
Inositol triphosphate IP3
Diacylglycerol DAG
What are G protein linked receptors response to hormone mediated by
Trimeric GTP binding protein
What are the 3 subunits of G proteins
Alpha
Beta
Gamma
What does hormone binding cause
A conformational change
What is the on coding
Gtp
What is the off coding
GDP
What does the intracellular domain interact with
G protein