Kevin Ahern's Bite-Sized Biochemistry #53 - Immune System & Grand Finale

1. Contact - [email protected] 2. Kevin's lectures with The Great Courses - https://www.thegreatcoursesplus.com/b... 3. Kevin's Lecturio videos for medical students - https://www.lecturio.com/medical-cour... 4. Course materials at https://kevingahern.com/biochemistry-... 5. Course video channel at    • Kevin Ahern's Bite-Sized Biochemistry #1: ...   6. Metabolic Melodies at https://teeheetime.com/category/lyric... 7. Kevin's Free Biochemistry books - https://kevingahern.com/biochemistry-... 8. Kevin's Pre-med Audio course on Listenable - https://listenable.io/web/courses/143... Sensory Systems II 1. The protein that binds the retinal in each of these is similar to the opsin of rod cells (40% identity). Color blindness (usually in males) arises due to recombination between related red and green receptor genes on the X chromosome. 2. Hearing arises as a result of signaling in the ear arising from hair cell micromanipulation (movement) arising from sound waves. Tipping of the cells causes little "tethers" to pull open ion channels that initiate a nerve signal. 3. Touch is the least understood sense. There are receptors for pressure, temperature and other sensations. Touch receptors can be linked to pain centers called nociceptors located in the spinal cord and brain. Interestingly, the compound capsaicin, which causes hot sensations in the mouth stimulates the same nociceptors. 4. The capsaicin receptor is a transmembrane protein. This protein contains a pore that opens to allow calcium ions in when capsaicin binds, thus initiating a nerve signal. Mice lacking the capsaicin receptor do not respond at all to capsaicin. Similarly, birds do not contain coding for a capsaicin receptor and are immune to it.