Cell complexity: ion channels (Introduction)

by David Turell , Friday, December 12, 2014, 14:28 (3415 days ago) @ David Turell

Cell membranes have pores which control thee in an out flow of ions, atoms without one electron. The body runs on 'wet electricity' different than the dry electricity of a computer. It takes extremely complex systems to do this.-http://darwins-god.blogspot.com/2014/12/potassium-channels-even-more-clever.html-"These positively charged ions enter and exit the cell via huge protein machines called channels which are imbedded in the cell wall and, like a donut, have a hole in the middle through which the ions flow. What is astonishing is how well these channels work. Not only do they open and close as needed, but they have two seemingly impossible design features. On the one hand they are extremely selective, allowing only a particular type of ion to flow through it. But on the other hand, they allow the chosen ions to flow through incredibly fast. It would seem that high selectivity would come at the cost of a slow transmission rate. But no, potassium channels for instance filter out practically everything but potassium ions, and yet their flow rate is practically at the maximum speed that is physically attainable. Now a recent study has added more information about how potassium channels perform their amazing feats."-
"Ion channels are proteins that line holes in the plasma membrane. They can open on demand to let ions in and out of the cell. They allow nerve impulses to travel, cause your heart to beat, and allow your muscles to contract. In many cells, channels and another kind of protein called a pump together maintain a relatively constant negative charge within your cells. This net negative charge, or membrane potential, affects the entry and exit of a variety of materials. page 15 of Bioinformatics, Genomics, and Proteomics: Getting the Big Picture-"10 million to 100 million per second!-
"The importance of these precise structures and hence functioning of protein machines like these channels cannot be understated. Potassium channels, like other channels that pass other ions from one side of the cell membrane to the other, have a particular architecture that allows them to open and close upon command. We now know that intricately designed and mechanically fine-tuned ion channels determine the rhythm and allow an electrical impulse initiated when we stub our toe to be transmitted to the brain.- Ibid page 19-"However even these, in comparison to electrons, huge ions also get lost in the wet environment. So what is needed are pumps along the way to pump ions in and also out. In the case of our nerve cells, ions go in to start the signal and are pumped out to reset that part of the system so it is ready for the next (or continuing) sensation."-http://www.uncommondescent.com/intelligent-design/potassium-channels-even-more-clever-than-thought/-Our entire body runs this way, and these descriptions are only a tiny part of the picture.