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Physio Ch. 5
Question | Answer |
---|---|
ligans bind to...and are ususally..such as... | receptors...chemical messengers...hormones, neurots and paracrine/autocrine agents |
paracrine/autocrine agent examples | histamine and nitric oxide |
chemical messengers NEED...which are generally... | receptors...proteins or glycoprotein with a chemical specific binding site |
receptors have...so it only binds to a... | specificity...specific ligand |
receptors are located in the... | cell plasma membrane (transmembrane protien) |
cell membranes allow | lipid insoluble messengers to enter the cell |
receptors can also be located | inside the cell or nucleus |
characteristics of messenger-receptor interactions | affinity, % saturation, and competition |
competition involves | agonists (promote activity) and antagonists (block activity) |
regulation of receptors is either | down or up regulation |
down regulation decreases | or decreases in the affinity of the receptor |
down regulation involves... | negative feedback mechanism |
neg. feedback mechanisms for regulatin receptors increases the... | amt of ligand > ^ messenger - receptor interaction |
^ amt of ligand > ^ messenger - receptor interaction increases...and involves the...which lastly... | amt of desired action...internalization of receptors (endocytosis) > ^ breakdown of receptors...decreases amount of reaction |
negative example of down-regulation would be | insulin resistance and dec insulin receptor sensitivity |
insulin resistance and dec insulin receptor sensitivity results in | dec glucose transporters in skeletal muscle and adipose tissue |
up-regulation involves the | addition of receptors to cell plasma membrane or increase in the affinity of the receptor (exocytosis) |
signal transduction pathways cause the...and involves the steps from.. | domino effect...signal to desired response |
signal transduction pathways involve | receptor activation and transduction |
receptor activation involves | messenger-recepter interaction |
transuction involves...and may also involve... | transformation of a signal to a response...many steps and many chemicals/reactions |
lipid soluble messengers in signal transduction pathways: the receptors are...and thelipid-soluble messengers can... | intracellular...pass through the phospholipid bilayer |
lipid soluble messengers that can pass through the phospholipid bilayer include | steriod hormones, thyroid hormones, and 1,25 hydroxyvitamin D (steroid derivative) |
most lipid soluble messengers alter...because the...act as a... | rates of DNA transcription...receptor and bound messenger...transcription factor |
lipid-soluble messengers may increase or decrease | gene activity |
plasma membrane receptors for...and their mechanism of transduction includes... | lipid soluble messengers...ion channels, enzymes, activate JAK kinases, activate G proteins |
the plasma membrane receptors for lipid soluble messengers: ion channels are | chemically ligand gated channels |
the plasma membrane receptors for lipid soluble messengers: enzymes are usually...and some receptors...or they... | kinases that phosphorylate a protein...act as enzymes...activate ligand protein as an ezymes |
the plasma membrane receptors for lipid soluble messengers: activating JAK kinases, jak stands for...and the receptor is not the...but it activates... | just another kinase...kinase...a seperate kinase and they you transfer energy to another molecule |
the plasma membrane receptors for lipid soluble messengers: activating G proteins, G protein complexes are in the...and the change in G proteins activates... | membrane...an additional protein |
G proteins may result in...or in... | change in membrane potential (get a response)...generation of a second messenger (get a response) |