The second MWM energy metabolism looks at how we use enzymes to exert exquisite control over what happens inside our bodies. If the second law of thermodynamics holds that entropy is always increasing, why don’t we reach maximum entropy right away? Why do we observe any order at all?  The activation energy represents the resistance to change that can be found in any substance. We exploit the concept biologically by maintaining a body temperature that provides insufficient energy for most relevant reactions to go forward without catalysis, and imposing upon this backdrop an expansive repertoire of enzymes that can, in a regulated fashion, lower the energy barriers sufficiently for reactions to go forward. This lesson looks at how they do that, and how we regulate their activity. Watch the full lesson at chrismasterjohnphd.com/mwm/2/2 Sign up for MWM Pro for early access to content, enhanced keyword searching, self-pacing tools, downloadable audio and transcripts, a rich array of hyperlinked further reading suggestions, and a community with a forum for each lesson.