BIO230H1 Lecture 20: lecture 20 review .docx
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BIO230H1 Full Course Notes
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Answer: small, hydrophobic molecules (water can be used in some cases through osmosis, but not always ) A very small signaling molecule: nitric oxide (no) Made by the deamination of arginine by no synthases. Made by the deamination of arginine by no synthases easily degradeable and acts very locally) Acts locally because of a 5-10 second half life. It is converted to no and relaxes blood vessels, reducing workload on the heart. Ligand binding alters receptor conformation, and releases inhibitors, Dna binding and downstream transcription to promote dna binding and downstream transcription. The transcriptional response to hormones can be complex. Ion channels are a major class of signaling molecules. Ion channels can be activated in a number of ways. A restricted outward leakage of potassium ions polarizes plasma membranes of excitable cells outside inside. Voltage-gated sodium channels produce and respond to action potentials.
