Tuesday, June 19, 2012

The Trenches of Discovery: The human machine: pistons and ratchets

This week, I thought it would be interesting to look at how ATP gets used up in a process that will be very familiar to you but that you probably know little about: muscle contraction.

As I mentioned last time, ATP is used by just about every active process that takes place in your cells. Most of these processes siphon only tiny amounts of ATP from the ever-replenished pool that is available in your cells – as far as they’re concerned there is an infinite amount of ATP available because they could never use is all up on their own. For this reason, a lot of our cellular machinery is, frankly, wasteful. The mechanisms that regulate DNA repair, movement of organelles within cells, and many other processes consume ATP with gay abandon because their impact is so miniscule on the total energy consumed by your body as a whole. There has been no need to evolve more cost-efficient mechanisms, such as those employed by our single-celled relatives for whom every ATP counts!

Read the rest at The Trenches of Discovery