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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) |