Ron Vale (UCSF, HHMI) 1: Molecular Motor Proteins

link I didn't realize there was also a Powering the Cell: Mitochondria video. The classic one narrated - link One of my pandemic YouTube binges was watching Ron Vale videos about kinesin and dynein. ▶ this video link link And searching for Ron Vale will bring a number of other videos about molecular machines.

If you think that’s cool you might also like to see the motor proteins that walk along inside our cells. There are a few types including the ones that make muscles work. Kinesin is fun because it has little legs made of proteins. It gloms onto big bubbles of stuff inside the cell and carries them along pathways to their destination. Chemical reactions cause the proteins to fold in the right way to take each step. This shows how they look. link This explains the mechanisms that they use to walk. ▶ this video

I only see simple biochemical machines in that video. Here’s what they look like when you zoom in a bit more: ▶ this video It’s literally chemical bonds breaking and forming, stochastically.

The genomic machinery is incredible complex and messy. Imagine some code, that is interpreted by little machines not created by that code, that then create other machines, that read that code in a different way, to create other machines, that copy that code, which is then read by other machines, etc, etc. These "machines" are chunks of molecules that require quantum mechanics to fully understand, and also tend to have a lot of issues with them. As an example of the weirdness, look at motor proteins: ▶ this video It's amazing how utterly mad it all is, and yet not only does it work, our simple models of how it works have actually been helpful even though they were wrong. I mean, it's not like there's actually a single value in your DNA that is looked up by some "eyeball creation" machine when it determines the color of your eyes. Rather, there's a whole slew of genes that, when used as a map to build proteins and then, over a cascade of complex reactions, ends up with an eyeball that is also blue (and, additionally, probably more light sensitive, more tolerant to alcohol, and also more likely to have alcohol use disorder) Source: work for genomenon.com which is like a search engine for genetic research papers)

When I see stuff like this I have to say I am amazed at how precise some drugs are. Somewhat related I was watching a video about protein motors and how they work. They are small structures that walk on microtubules (as mentioned in the Alzheimer's article) inside cells. There are many types but some walk using hinged protein feet. The narrator explained how his team invented a drug that helped to make one step in that process better. They made the hinge part of the foot work normally giving it more strength. It was a single phosphate molecule added to this step. It was incredible to think one small part of a protein motor the "ankle" part of the foot of that one protein motor on a microtubule inside a single cell had some help. I explained it horribly here is the video ▶ this video edit: phosphate not sulphur